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Car Forum / Driving, Maintenance, Tuning / Maintenance and Repair / April 200889 Escort LX 1.9L CFI -- Fuel delivery is out of wack
The continuing saga of a dear friend's 89 Escort LX 1.9L with Central Fuel Injection (it has a throttle body with a single injector)... I have ruled out spark as the problem. Spark is good. I caught the fuel injector in the act of not injecting fuel when it should, and all the while the coil is firing a healthy spark to all the plugs. I replaced the fuel filter on the off chance that I was having a good day and that would solve the problem. The gods would have none of it. I wasn't having a good day... not as far as reviving my dear friend's Escort goes. Many other things went surprisingly well. Little things, but very much appreciated. Wiping the previous slate clean, I offer the following symptoms: Sometimes the injector will spray gas and sometimes it won't. When the injector will not spray gas, there is fuel and pressure in the fuel pressure regulator. I confirmed this by unscrewing the fuel pressure regulator cover and watching as fuel sprayed out with surprised force and duration. Therefore I have taken it into my head that the problem must lie with either the injector, a sensor, faulty wiring or the computer. I can hear the electric fuel pump doing its thing and the fuel pressure regulator seems to be full of pressurized fuel. Whether the pressure is up to specs, I don't know, but I was mightily impressed with the force with which is sprayed out when I loosened the screws of the fuel pressure regulator cover. Another symptom is that the engine tries to stall immediately after starting. I can keep it alive by constantly pumping the gas pedal. No one position on the gas pedal will keep the engine running, but pumping it will. But that is no way to go through life. At present, the engine seems to start consistently but will not run. I don't have a noid light to check the signal to the injector wiring, but since the injector sometimes works I have to assume that the wiring sometimes works as well. The Chilton manual suggests that the Throttle Position Sensor plays a role in the correct operation of the fuel injection system, as does the PCM (Powertrain Control Module, or engine computer). I'll give that last one a great big 'DUH'. The Chilton manual spells out some diagnostic procedures which I will endeavor to undertake in the coming days. However, my vast arsenal of tools does not include noid lights to check injectors as I am new to fuel injection. I may buy some... or I may not. It all depends on whether or not I solve the problem without them while I waffle on their purchase. God, I hope to hell, for the sake of future generations, the world transits soon to electric vehicles.  Signature"Forget it, Jake. It's the Internet." > The continuing saga of a dear friend's 89 Escort LX 1.9L with Central > Fuel Injection (it has a throttle body with a single injector)... [quoted text clipped - 45 lines] > whether or not I solve the problem without them while I waffle on their > purchase. Noid lights are handy but they're not absolutely necessary. You could rig a #194 bulb to work the same. Possibilities; Either the injector is being commanded to NOT allow fuel or there is an electrical problem with it. The return voltage from the TPS could be high enough that the ECM is interpreting it as a clear flood command. or The injector is shorted or open and is electrically incapable of operating. Check the return (signal) TPS voltage, at idle position, it should be under 1.00 volts. Measure the resistance of the injector windings, are they in spec? Confirming fuel pressure would be a smart step also. 'squirts good when I crack a line' isn't in any manual I've ever read.... What happens if you pressurize the system up and then activate the injector with a couple of jumper leads? Does fuel spray? What if the coolant sensor is shorted and the ECM thinks the engine is hotter than it actually is, what do you suppose the injector pulse would be, shorter or longer than needed? Do you get more fuel spray if you unplug it? What if the MAP sensor was reading a much higher altitude than actual, shorter or longer injector pulse? Do you get more fuel spray if you unplug it? Do you have 5 volt reference voltage at the CTS, TPS and MAP sensors? You don't need a noid light, you need a clear path of deductive logic. >> The continuing saga of a dear friend's 89 Escort LX 1.9L with Central >> Fuel Injection (it has a throttle body with a single injector)... [quoted text clipped - 82 lines] > > You don't need a noid light, you need a clear path of deductive logic. I got the engine to the point where it blows black smoke at a rough idle and is perfectly driveable. It didn't stall in several miles of driving. I checked the TPS with a DVOM as per the Chilton manual (probably the same in the Ford service manual). It had good 5 volt Vref, but the manual said it should read 'approximately' zero at idle, but this read .76 volts. I disconnected the wiring harness from the TPS to get closer to 'approximately' zero, but this did not change the rough idle/black smoke condition. Disconnecting the CTS didn't change anything either. I didn't get around to checking the increasingly suspicious MAP sensor, but will do so in a day or two. The single fuel injector in the throttle body was looking good today, but just too much gas at idle. Even I, who am new to EFI could see that. More as I get to it. And thanks... Signature"Forget it, Jake. It's the Internet." As a diagnostic procedure for ruling out sensors as a cause of rough idle and black smoke at the tailpipe, how does this sound: Disconnect the O2 sensor or the MAP sensor or the TPS, forcing the computer into limp mode, and see if this changes the rough idle and black smoke at idle. I am away from the car at the moment or I would try it now. I was just doing some google and google groups searches on this problem of a TBI engine dumping too much fuel at idle, causing rough idle and black smoke out the tailpipe and the idea of forcing the computer into limp mode came up in one discussion of this problem. If forcing the computer into default 'limp' mode does *not* change the problem, that would seem to indicate that the problem is *not* sensor based. Does that sound like correct logic? If the problem is not sensor based, it must be component based, i.e. the injector, components that maintain fuel pressure, engine computer, vacuum hoses, etc. I have yet to test the MAP sensor and the fuel pressure. The first is easily within my reach but the second will require some nosing around to find the "fuel pressure diagnostic valve" mentioned in the Chilton manual, but not pictured. One is asked to "Locate the fuel diagnostic valve on the fuel rail". This may be fine for the MFI, Multi-Port Fuel Injection, but this car has the CFI, Central Fuel Injection, with a single throttle body injector. What is really discouraging is that every single discussion that I have found dealing with this kind of problem on a vehicle with fuel injection ends without resolution. Not a single one ends with the OP coming back to post what fixed the problem. I think that most people would want to come back to the discussion and crow about finding the solution. I would. Signature"Forget it, Jake. It's the Internet." > As a diagnostic procedure for ruling out sensors as a cause of rough idle > and black smoke at the tailpipe, how does this sound: > > Disconnect the O2 sensor or the MAP sensor or the TPS, forcing the computer > into limp mode, and see if this changes the rough idle and black smoke at > idle. And if it does change, then what ?? I am away from the car at the moment or I would try > it now. I was just doing some google and google groups searches on this > problem of a TBI engine dumping too much fuel at idle, causing rough idle > and black smoke out the tailpipe and the idea of forcing the computer into > limp mode came up in one discussion of this problem. See above. If you disconnect a sensor, it puts the computer in "limp mode" and the vehicle now runs better, what does it prove ? It proves nothing ! Every time you unplug a sensor ( ANY sensor ) it should go into limp mode. When in limp mode it may not use any sensor values and run on a pre programed map in the ECU. In that instance, ant sensor you unplug will have exactly the same effect. It all depends on how the ECU is programed to operate. > If forcing the computer into default 'limp' mode does *not* change the > problem, that would seem to indicate that the problem is *not* sensor based. > Does that sound like correct logic? No. What if the problem was a broken wire in the harness going to a sensor ? If you unplug the sensor you still have an open connection and it will still run the same. Why not start with basic diagnostics first ? Is the check engine light on ? Did you check for stored codes, even if the light ISN"T on ? Do you have a scan tool that is capable of reading sensor values ? Another piece of info that may be helpful, DO NOT DRIVE THE CAR if it is running that rich as you will ruin the catalytic converter, it will overheat and melt from the excess fuel. If the problem is not sensor > based, it must be component based, i.e. the injector, components that > maintain fuel pressure, engine computer, vacuum hoses, etc. [quoted text clipped - 11 lines] > post what fixed the problem. I think that most people would want to come > back to the discussion and crow about finding the solution. I would. >> As a diagnostic procedure for ruling out sensors as a cause of rough idle >> and black smoke at the tailpipe, how does this sound: [quoted text clipped - 4 lines] > > And if it does change, then what ?? That would indicate that the problem could be the result of a malfunctioning sensor. Since limp mode does not depend on sensor input, if the engine runs *better* in limp mode, then that would indicate that the actually components involved in delivering fuel are working okay and one or more sensors may be at fault. If the engine runs *the same* in limp mode, that would indicate that the components involved in delivering fuel may be faulty since both limp mode and computer control mode depend on these components. > I am away from the car at the moment or I would try >> it now. I was just doing some google and google groups searches on this [quoted text clipped - 4 lines] > See above. If you disconnect a sensor, it puts the computer in "limp mode" > and the vehicle now runs better, what does it prove ? It proves nothing ! Sure it does. It proves that the fuel pump, fuel pressure regulator, and injector are capable of functioning better than they are at present with the sensors informing the computer. If I'm not mistaken, all that is removed from the system in limp mode is sensor input, which is replaced by a computer program. Obviously, the computer needs *some* input, such as rpm, but it can do without the O2, MA, ECT and knock sensors. I'm not sure about the TPS. Does any computer ignore the TPS in limp mode? > Every time you unplug a sensor ( ANY sensor ) it should go into limp mode. > When in limp mode it may not use any sensor values and run on a pre programed > map in the ECU. In that instance, ant sensor you unplug will have exactly the > same effect. It all depends on how the ECU is programed to operate. All I am trying to accomplish by putting the computer into limp mode is to determine whether the problem is sensor based or component based. If the computer is getting bad info from a sensor and is responding accordingly, then forcing the computer into limp mode should remove that bad input and the computer will, as you point out, replace it with a program. Right now, at idle, the engine is running so badly that, if the problem is with a faulty sensor or faulty sensor wiring, I would expect to see an improvement when the limp mode program takes over. If the car runs just as poorly in limp mode, then the fault *must* lie with the components and not the sensors, which have been removed from the system. I will report everything. >> If forcing the computer into default 'limp' mode does *not* change the >> problem, that would seem to indicate that the problem is *not* sensor based. [quoted text clipped - 7 lines] > Did you check for stored codes, even if the light ISN"T on ? Do you have a > scan tool that is capable of reading sensor values ? The check engine light hasn't come on while the engine was running since I started this project. It comes on when the key is in run position and the engine is not running, so I know the light works. I disconnected the battery several times since starting work to clear the computer to see if that affected the problem. It hasn't been disconnected for the last 5 or 6 starts and having been driven for about a mile, so if codes were set, they are still in there. I just looked in the manual and all that is needed to read the codes is an analog meter, which I have. I will definitely check for fault codes. As for the sensor values, I can check them with a DVOM. The TPS checked out okay. I plan on checking the MAP sensor next. I may be wrong, but I don't think any other sensor malfunction would cause this heavy black smoke at idle. As this is a single injector throttle body system, I don't believe there is an Idle Air Control Valve > Another piece of info that may be helpful, DO NOT DRIVE THE CAR if it is > running that rich as you will ruin the catalytic converter, it will overheat [quoted text clipped - 16 lines] >> post what fixed the problem. I think that most people would want to come >> back to the discussion and crow about finding the solution. I would. >>> As a diagnostic procedure for ruling out sensors as a cause of rough >>> idle and black smoke at the tailpipe, how does this sound: [quoted text clipped - 7 lines] > That would indicate that the problem could be the result of a > malfunctioning sensor. I'm curious why you haven't responded to aarcuda. He made some awfully good suggestions in his reply to you. SignatureTegger >>>> As a diagnostic procedure for ruling out sensors as a cause of rough >>>> idle and black smoke at the tailpipe, how does this sound: [quoted text clipped - 9 lines] > I'm curious why you haven't responded to aarcuda. He made some awfully good > suggestions in his reply to you. I *did* respond to him with what I had at that point. The post is right there dated 4/3 at 4:46 pm. I'm surprised you didn't see it. I got started on his suggestions and reported what findings I got at that point. He wrote, "Possibilities; Either the injector is being commanded to NOT allow fuel or there is an electrical problem with it. The return voltage from the TPS could be high enough that the ECM is interpreting it as a clear flood command. or The injector is shorted or open and is electrically incapable of operating." I opened with "I got the engine to the point where it blows black smoke at a rough idle and is perfectly driveable. It didn't stall in several miles of driving." That indicates that the injector was now working. There was a stretch where it was not spraying gas when the engine was cranked, but that condition changed. Don't ask me how. One theory is that the car is haunted, the previous owner is dead and wants it back. But I'm not running with that one yet. Since the engine was now running, but blowing black smoke at idle, there seemed no need to check the injector. It was obviously injecting gas and doing a good job of it once the car was moving. It drove perfectly once over 5 or 10 mph. The problem may yet be the injector, but this is as far as I have gotten with it so far He suggested, "Check the return (signal) TPS voltage, at idle position, it should be under 1.00 volts." I reported back, "I checked the TPS with a DVOM as per the Chilton manual (probably the same in the Ford service manual). It had good 5 volt Vref, but the manual said it should read 'approximately' zero at idle, but this read .76 volts." He wrote, "Confirming fuel pressure would be a smart step also." I agree, but I don't have the capacity at present to do that. He wrote, "What if the coolant sensor is shorted and the ECM thinks the engine is hotter than it actually is, what do you suppose the injector pulse would be, shorter or longer than needed? Do you get more fuel spray if you unplug it?" I responded, "Disconnecting the CTS didn't change anything..." He wrote, "What if the MAP sensor was reading a much higher altitude than actual, shorter or longer injector pulse? Do you get more fuel spray if you unplug it? I responded, "I didn't get around to checking the increasingly suspicious MAP sensor, but will do so in a day or two." He wrote, "You don't need a noid light, you need a clear path of deductive logic." And I am trying to develop one while I am away from the vehicle so that when I go back I can use my time more efficiently. That's why I asked the question about forcing the computer into limp mode as a means of determining whether the fault was sensor-based or component-based. It makes sense to me. Mike shot it down, but the more I thought about it, the more convinced I became that it can be a valid diagnostic technique and I plan to try it, and then focus my attention on either the sensors or the components based on the results I get. It takes about ten seconds to pop the hood and disconnect the O2 sensor and anothe ten seconds to get in and start the engine. If no black smoke, then the problem is probably sensor-based. If black smoke, then the problem is probably component-based, and by that I mean the actual components involved in delivering the fuel to the intake manifold, not sensors that report to the computer. This includes fuel pump, fuel pressure regulator and injector. If that is the problem, then checking the fuel pressure becomes more important. But if I get no black smoke in limp mode, then it makes more sense to check the sensors first. In closing, you obviously did not see my response to aarcuda or you would not have tried to bust me for not responding to him or following his suggestions. Other than mistakenly criticizing me, do you have anything of substance to add to the actual matter at hand? > The check engine light hasn't come on while the engine was running since > I started this project. Mid to late 80s Fords do not illuminate the check engine light like GM and Chrysler cars do. > It comes on when the key is in run position and > the engine is not running, so I know the light works. I disconnected the [quoted text clipped - 4 lines] > is needed to read the codes is an analog meter, which I have. I will > definitely check for fault codes. Warm the engine up, do a "Key On Engine Off" self test. Record the codes. Then do a "Key On Engine Running" self test. Record the codes. > As for the sensor values, I can check them with a DVOM. The TPS checked > out okay. I plan on checking the MAP sensor next. I may be wrong, but I > don't think any other sensor malfunction would cause this heavy black > smoke at idle. An open Engine Coolant Temperature sensor certainly would. > As this is a single injector throttle body system, I don't believe there > is an Idle Air Control Valve It probably has an Idle Speed Control motor, an external device that pushes against the throttle linkage much like the early GM CCC carbed cars used. I will now re-boot into Windoze, log onto MOD and verify. > > The check engine light hasn't come on while the engine was running since > > I started this project. [quoted text clipped - 31 lines] > > I will now re-boot into Windoze, log onto MOD and verify. Well, that was painful... The 89 Escort came with two EFI systems that operated at drastically different fuel pressures. Knowing that, I'd really-really-really want to measure the fuel pressure since it stands a good chance that the wrong pump would cause the exact symptoms you're describing. Forget looking for a pressure test port. There isn't one on CFI. You need an adaptor. CFI fuel pressure spec is 14.5 PSI SFI fuel pressure spec is 35-40 Looking at the wiring diagrams for this system, you should not need a analog volt meter to retrieve trouble codes. The check engine light is wired in parallel with the STO circuit so it should flash the binary codes when STI is jumped to pin 2 of the EEC test connector. (looks like you can do it either way though...) This arrangement further proves WHY the check engine light doesn't come on as expected if there is a trouble code lurking. One last item; these vintages of Ford products were lousy for EEC ground problems. Since the EEC self tests by design activate certain EEC components, the self test is a good time to voltage drop the ground circuit between the ECM and battery negative. >>> The check engine light hasn't come on while the engine was running since >>> I started this project. [quoted text clipped - 35 lines] > since it stands a good chance that the wrong pump would cause the exact > symptoms you're describing. The symptoms I am describing only started a few days ago. Before that engine ran perfectly through complete range of rpms. Plugs looked perfect. Based on that I am all but certain that the fuel pump os the right one. > Forget looking for a pressure test port. There isn't one on CFI. > You need an adaptor. I came to that same conclusion. If I get to the point where checking the fuel pressure becomes the best thing to try next, I will figure out how to do it, but there are other easier test to run that will help narrow the search. > CFI fuel pressure spec is 14.5 PSI > SFI fuel pressure spec is 35-40 [quoted text clipped - 4 lines] > codes when STI is jumped to pin 2 of the EEC test connector. > (looks like you can do it either way though...) One way or another I'll run both tests. > This arrangement further proves WHY the check engine light doesn't come > on as expected if there is a trouble code lurking. [quoted text clipped - 3 lines] > components, the self test is a good time to voltage drop the ground > circuit between the ECM and battery negative. Sorry but you lost me on that last one :-) > The symptoms I am describing only started a few days ago. Before that > engine ran perfectly through complete range of rpms. Plugs looked > perfect. Based on that I am all but certain that the fuel pump os the > right one. Was any service work done immediately prior to when it began running bad? > > One last item; these vintages of Ford products were lousy for EEC ground > > problems. Since the EEC self tests by design activate certain EEC > > components, the self test is a good time to voltage drop the ground > > circuit between the ECM and battery negative. > > Sorry but you lost me on that last one :-) Voltage drop= the proper way to measure resistance in a circuit. Positive meter lead back probed into the ground wire at the ECM, negative meter lead connected as directly to the battery negative as possible, run the self test which will flow as much current as possible (under reasonable circumstances) thru the ground circuits, watch volt meter reading, shouldn't go above .1 volt. >> The symptoms I am describing only started a few days ago. Before that >> engine ran perfectly through complete range of rpms. Plugs looked >> perfect. Based on that I am all but certain that the fuel pump os the >> right one. > > Was any service work done immediately prior to when it began running bad? Just before I was called in, someone else replaced the timing belt and water pump. He was called in because the car stalled twice. He said it was a broken timing belt, which got me very suspicious. 1. The engine stalled twice while the car was being driven. You can't restart an engine with a busted timing belt. 2. The car continued to stall after the timing belt was 'replaced'. I will have to ask my friend if anything was done to the car by anyone just prior to the stalling problem. There are two distinct problems. 1. The engine stalls without warning. 2. The engine blows black smoke from the exhaust at idle due to an excessive of fuel pouring into the throttle body from the injector. Changing the notoriously flaky ignition module did not solve the stalling problem. The stalling problem came on first. The plugs were all toasty tan colored when I checked them and the car idled smoothly and correctly. The black smoke from the exhaust began after I became involved. The first thing I did was remove the air filter housing and plastic intake air ducting to familiarize myself with the layout. To do this, I removed two vacuum hoses, one to the PCV valve and one to the heated air inlet diaphragm on the plastic intake air duct. Both were plugged for any engine running tests that were done with all that baggage removed. Assembly was the reverse of removal, as they say. I can imagine the 'aha!' moment this info might impart, and believe me, I, too, suspect that it must be something that I did to cause the excessively rich idle. The vacuum hoses will all be checked again today... for the umpteenth time. I plan to crack this nut today or tomorrow or die trying. I'll report back. >>> One last item; these vintages of Ford products were lousy for EEC ground >>> problems. Since the EEC self tests by design activate certain EEC [quoted text clipped - 9 lines] > (under reasonable circumstances) thru the ground circuits, watch volt > meter reading, shouldn't go above .1 volt. Got it! Signature"Forget it, Jake. It's the Internet." > 1. The engine stalls without warning. > > 2. The engine blows black smoke from the exhaust at idle due to an > excessive of fuel pouring into the throttle body from the injector. This sounds like one problem not 2. Very rich idle would be likely to cause stalling. Are you saying problem 2 was not there until after you worked on it? Or that you don't know if it was there before? Are the vaccum hoses you messed with in bad shape? -jim > Changing the notoriously flaky ignition module did not solve the > stalling problem. [quoted text clipped - 35 lines] > > "Forget it, Jake. It's the Internet." ----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups ---= - Total Privacy via Encryption =--- > >> The symptoms I am describing only started a few days ago. Before that > >> engine ran perfectly through complete range of rpms. Plugs looked [quoted text clipped - 11 lines] > > 2. The car continued to stall after the timing belt was 'replaced'. Have you verified that the timing belt is installed correctly, that the cam timing is correct? Is the ignition timing correct, have the plug wires been shuffled on the distributor cap, is the mark for the distributor hold down still where it has been for the last 20 years? >>>> The symptoms I am describing only started a few days ago. Before that >>>> engine ran perfectly through complete range of rpms. Plugs looked [quoted text clipped - 16 lines] > distributor cap, is the mark for the distributor hold down still where > it has been for the last 20 years? I haven't yet, but I can check those two things. I have the car at my place now, which makes it easier to work on. I checked for stored codes and got the following: 11 O/R/C -- System pass I ran a KOEO test with the engine fully warmed up and got the following: 32 R/C ---- EGR valve not seated 41 C ------ No EGO/HEGO switching detected, system lean 51 O/C ---- ECT sensor input exceeds test maximum 53 O/C ---- TP sensor input exceeds test maximum 63 O/C ---- TP sensor input below test minimum 87 O/R/C -- Fuel pump primary circuit failure O - Key On, Engine Off R - Engine running C - Continuous memory The KEOR test requires that the engine be revved to 3000 rpm and held for the duration of the test and I want to wait a bit before destroying the tranquility of the day. I haven't yet tested the EEC ground. That will be next The fact that the TP sensor both exceeds test maximum and falls below test minimum is interesting. (three hours later) I decided to clear the computer after pulling the codes to see if they were a current condition or no longer valid. The car seemed to be running well, so I took a chance and drove three miles through city traffic and got on the freeway with it. I drove it about seven miles on the freeway and drove it back going up and down hills with lots of stop and go. Before getting on the freeway I pull the codes from the computer to see if any had set. Nothing but '11'- 'system passed'. I pulled codes again after coming back from the freeway and the hills and again, the same thing - a clean bill of health. Yesterday my friend, who owns this car, made mention of a woman neighbor of hers who has a bit of a mental condition and mentioned that a trusted man in the neighborhood told her to get a locking gas cap for her car because this woman was capable doing something wacky like pouring a none-gasoline substance down the gas tank of anyone from whom she perceived a slight. This woman is in the process of moving from this neighborhood and this trusted man of the neighborhood feared that this woman might decide to give certain individuals a going-away present. I don't know what effect a quart of water in a gas tank would have, but I noticed early on that water was leaking from the weep hole in the muffler at idle. The more the engine was revved, the more water came out. It went from being a steady drip to being a steady trickle. I figured it might be a blown head gasket. Their was no coolant in evidence in this drip and the cooling system is half and half. I'm not sure if coolant would be evident coming from the exhaust of a system with a blown head gasket. But I put that problem aside to concentrate on the problem of stalling, which became supplanted by the problem of the smoky, sooty exhaust. The problem with the sooty exhaust showed up the morning of the second day from when I began working on this car, and that correlated with the super heavy gas flow coming out of the injector. As it is now, the car is running fine, there is no smoke from the exhaust, no water is dripping from the muffler, it hasn't stalled in over twelve miles of driving in all kinds of conditions, the plugs are back to normal, there are no fault codes in memory and the idle speed is comfortably within specs and I don't know what happened. The fuel problem went from being grossly rich to grossly lean to the point of stalling and not restarting. When the injector wouldn't shoot gas, the fuel pressure regulator had pressure that shot gas out when I backed off a screw on the cover. The next day the engine started right up and ran fine, then started smoking again. Today the engine began running fine, but later developed a bit of sooty exhaust but no where near as bad as the first day of sooty exhaust. The tank was down to less than a quarter full and my friend put in enough to get up over a half a tank and now there is no soot in the exhaust. I haven't checked the timing, but the distributor and the head had some tick marks that lined up and when I changed the ignition module I made another pair and lined them all back up when I was done. I am totally stumped as to what happened. All those fault codes listed above happened after the last time I cleared the computer while working on the car. I may have ran the engine with the TPS disconnected, but not the o2 sensor or the ECT sensor and whatever caused the EGR code to be set is fine now, as is the fuel pump primary circuit failure, which has me most concerned, as the fuel pump was supposed to have been changed recently and it is inside the gas tank. At this point, I'm thinking wiring problems or the computer, but at present, it ain't broke and if it ain't broke I can't fix it and, God, I hope it don't break again. Signature"Forget it, Jake. It's the Internet." > > Have you verified that the timing belt is installed correctly, that the > > cam timing is correct? [quoted text clipped - 4 lines] > > I haven't yet, but I can check those two things. Given the prior history, I can't imagine why this wasn't one of the first things done. > I have the car at my place now, which makes it easier to work on. > [quoted text clipped - 5 lines] > > 32 R/C ---- EGR valve not seated Certainly could cause the symptoms described. > 41 C ------ No EGO/HEGO switching detected, system lean Shorted O2 sensor, would drive the mix rich. > 51 O/C ---- ECT sensor input exceeds test maximum > 53 O/C ---- TP sensor input exceeds test maximum > 63 O/C ---- TP sensor input below test minimum I gotta think you set these during your 'testing.' > 87 O/R/C -- Fuel pump primary circuit failure Interesting... > O - Key On, Engine Off > R - Engine running [quoted text clipped - 3 lines] > for the duration of the test and I want to wait a bit before destroying > the tranquility of the day. Held at 3000 RPM? According to who? There is a point during the engine running self test when the throttle needs to be snapped, but never have I seen it required that the engine speed be held at 3000 RPM. You -really- need to find better reference material. > I haven't yet tested the EEC ground. That will be next > > The fact that the TP sensor both exceeds test maximum and falls below > test minimum is interesting. If you held the RPM at 3000 during any portion of the self test, that's where it came from. > (three hours later) > [quoted text clipped - 22 lines] > out. It went from being a steady drip to being a steady trickle. I > figured it might be a blown head gasket. Water is a natural byproduct of combustion. > Their was no coolant in > evidence in this drip and the cooling system is half and half. I'm not [quoted text clipped - 26 lines] > tick marks that lined up and when I changed the ignition module I made > another pair and lined them all back up when I was done. One set of tic marks is from the factory, if the ignition timing is correct (as checked with a timing light, spout connector un-plugged) then it's a safe bet the cam timing is correct. But, lining up tic marks is NOT a substitute for a timing light. > I am totally stumped as to what happened. All those fault codes listed > above happened after the last time I cleared the computer while working > on the car. I may have ran the engine with the TPS disconnected, but not > the o2 sensor or the ECT sensor You will get an ECT sensor code if the self test is run without warming up the engine. Being as you're the third cook to fry this bacon, who knows where it came from. > and whatever caused the EGR code to be > set is fine now, as is the fuel pump primary circuit failure, which has > me most concerned, as the fuel pump was supposed to have been changed > recently and it is inside the gas tank. "Primary" may refer to the primary winding of the fuel pump relay, it wouldn't necessarily have anything to do with the fuel pump itself. Now, since we now know that the fuel pump was recently replaced, scrutiny of the repair order for that job to determine whether the correct pump part number was used is in order. > At this point, I'm thinking wiring problems or the computer, but at > present, it ain't broke and if it ain't broke I can't fix it and, God, I > hope it don't break again. >>> Have you verified that the timing belt is installed correctly, that the >>> cam timing is correct? [quoted text clipped - 6 lines] > Given the prior history, I can't imagine why this wasn't one of the > first things done. Given that the problem was stalling and nothing else, would it make sense to check the timing first? The guy who changed the timing belt is a full-time mechanic. I'm a carpenter. I have to assume that a full time mechanic is as good at what he does as I am at what I do and I'm pretty damn good at what I do. I'm probably better than some full time mechanics. I expect you are, too. The black smoke came back and the plugs are full of black soot again. What I am dealing with is an intermittent condition that just won't hold still. Now it becomes a question of just how worth it is it to continue. My friend only wants a car she can rely on. She turned to me as a last resort because I once resurrected a 96 Kia Sephia that she bought for 3 grand and it was dead a week later and no one could fix it. Turned out it was a shorted hot wire to something by the gas tank and it fried the computer. It took me two months and two computers from Car-Parts.com but I tracked it down and fixed it. I just got news that my cousin's grandson needs a cheap car to commute to his telemarketing job selling double paned windows. I think I can get $300 for this doggie. SOLD! > >> I have the car at my place now, which makes it easier to work on. [quoted text clipped - 134 lines] >> present, it ain't broke and if it ain't broke I can't fix it and, God, I >> hope it don't break again. Signature"Forget it, Jake. It's the Internet." > > Given the prior history, I can't imagine why this wasn't one of the > > first things done. > > Given that the problem was stalling and nothing else, would it make > sense to check the timing first? Does it make sense that a stalling problem is now a black smoke-sooted plugs-no injector pulse one day-too much injector pulse the next day problem? You HAVE to cover the basics, with emphasis on anything that was dicked with before it landed in your lap. > The guy who changed the timing belt is > a full-time mechanic. I'm a carpenter. I have to assume that a full time > mechanic is as good at what he does as I am at what I do and I'm pretty > damn good at what I do. I'm probably better than some full time > mechanics. I expect you are, too. I'm only as good as a full time mechanic because that is what I am. But since I got your ear; should I square up the end of this 2X4 or should I assume that it's square from the lumber mill? > The black smoke came back and the plugs are full of black soot again. I'm not surprised. > What I am dealing with is an intermittent condition that just won't hold > still. That's why I had gray hair at 23... > Now it becomes a question of just how worth it is it to continue. > My friend only wants a car she can rely on. She turned to me as a last [quoted text clipped - 3 lines] > computer. It took me two months and two computers from Car-Parts.com but > I tracked it down and fixed it. Not good when a customer isn't committed. > I just got news that my cousin's grandson needs a cheap car to commute > to his telemarketing job selling double paned windows. I think I can get > $300 for this doggie. > > SOLD! >>> Given the prior history, I can't imagine why this wasn't one of the >>> first things done. [quoted text clipped - 7 lines] > You HAVE to cover the basics, with emphasis on anything that was dicked > with before it landed in your lap. You know, the first two days were like two wrestlers circling the ring, me and this car. Then they lunge for each other and the battle is on and although the tide of the battle may shift back and forth, only one will emerge the victor. In the beginning, I was determined to win. >> The guy who changed the timing belt is >> a full-time mechanic. I'm a carpenter. I have to assume that a full time [quoted text clipped - 6 lines] > But since I got your ear; should I square up the end of this 2X4 or > should I assume that it's square from the lumber mill? The lumber yards around here are getting pretty good about square ends on their 2x4s. The time spent checking each one adds up to way more time than assuming they are all square and then dealing with that one out 200 that isn't. > >> The black smoke came back and the plugs are full of black soot again. [quoted text clipped - 5 lines] > > That's why I had gray hair at 23... At this point, the best way to proceed, given that the problem won't hold still but comes and goes without any discernible pattern as of yet, is to let her drive the car and see if a pattern emerges of when the sooty exhaust condition is present. (two hours later) 1. I made sure codes were cleared from the computer. 2. I disconnected the o2 sensor and the MAP sensor and drove the car. 3. I pulled codes and got code 22--'MAP sensor input out of test range'. 4. I reconnected the MAP and o2 sensors. 5. Cleared codes and disconnected only the o2 sensor and drove the car. 6. Pulled codes and got code 11--'System pass', still with wet, sooty exhaust. When running the KOEO test, the computer does not detect the disconnected o2 sensor. (a half hour later) The computer does not report a fault with the o2 sensor unplugged and the engine off, but sets code 41 'No EGO/HEGO switching detected, system lean' in memory after driving a stretch in city traffic. (another two hours later) I pulled the plug on the computer to make it relearn everything and then drove it for twelve miles on the freeway. When I got back I ran a KOEO and a KOER and checked for fault codes in the memory. Everything came up '11', 'system passed'. There is no black smoke or water from the exhaust and it runs like it used to before all the problems started. I haven't pulled a plug yet. but will after I eat something. I'm certain it's a toasty tan color and nit black with soot. My friend wants me to hang onto the car for a few days. She does not want to be the guinea pig in case it stalls. I don't blame her. >> Now it becomes a question of just how worth it is it to continue. >> My friend only wants a car she can rely on. She turned to me as a last [quoted text clipped - 5 lines] > > Not good when a customer isn't committed. It was for a dear friend and not for money and therein lies the rub. I like a good broken-car challenge now and then, especially one that doesn't involve grease and skinned knuckles. > >> I just got news that my cousin's grandson needs a cheap car to commute >> to his telemarketing job selling double paned windows. I think I can get >> $300 for this doggie. >> >> SOLD! NOT SOLD! My friend won't sell the car to someone if it's not working right and if it's working right she wants to keep it. If it's not working right and there is no hope for it to ever work right, she wants to junk it. She doesn't want the karma of passing on a headache to someone, even if that person knows what's up with the car. Signature"Forget it, Jake. It's the Internet." >> The symptoms I am describing only started a few days ago. Before that >> engine ran perfectly through complete range of rpms. Plugs looked [quoted text clipped - 16 lines] > (under reasonable circumstances) thru the ground circuits, watch volt > meter reading, shouldn't go above .1 volt. If I get 12 volts is that an indication of a faulty computer? The ground wire going to the ECM is good. I checked it. Signature"Forget it, Jake. It's the Internet." > >> The symptoms I am describing only started a few days ago. Before that > >> engine ran perfectly through complete range of rpms. Plugs looked [quoted text clipped - 18 lines] > > If I get 12 volts is that an indication of a faulty computer? No, it indicates an open ground circuit. > The ground wire going to the ECM is good. I checked it. Checked it how? If you did the voltage drop test correctly, the ground isn't good, that's the point of the test. >>>> The symptoms I am describing only started a few days ago. Before that >>>> engine ran perfectly through complete range of rpms. Plugs looked [quoted text clipped - 17 lines] > > No, it indicates an open ground circuit. Yes! of course! what was I thinking (smacks forehead) On second thought, my question was based on incorrect thinking on my part. You'll have to excuse me on that one. I was thinking that if I used a volt meter to back probe a wire going into the computer, one that is supposed to be grounded by the computer, and attached the other probe to battery negative, and got 12 volts, then, providing that the ground wire from the computer harness is intact, the computer could be at fault, in other words, the computer would not be performing its grounding function. But that's not what you wrote. > >> The ground wire going to the ECM is good. I checked it. > > Checked it how? I did a continuity test between the ground wire at the disconnected computer harness and ground at the battery. It's good. Don't get pissed but I didn't do the voltage drop test yet. It was a struggle just to get to the computer, which is now sitting in front of me. I almost broke something in my back getting it out. Earlier, when the injector was not spraying gas while cranking, I hooked up a #194 bulb to the wiring harness for the injector like you said and cranked. Nothing. Then I hooked up the injector directly to the battery like you said and it sprayed gas. Then I checked the hot wire at the injector harness and it had 12 volts when the key was in the run position. It remained hot for a few seconds after the key was turned to the off position. Then I checked the signal wire from the injector harness for continuity to the computer harness and it was continuous. The only conclusion that I could come to was that *at that moment*, while cranking the engine, the computer was not grounding the injector circuit like it should. Then I started thinking, "What if the computer is good? What else might cause the computer to act this way?" I started searching again and found this. It's dealing with EFI on Chrysler cars. http://www.allpar.com/fix/fixee.html (scroll down about half way) ------------------------------------------------------------------------- Bohdan Bodnar wrote: Let's go to the fundamentals before troubleshooting. On EVERY EFI engine, the computer expects to see pickup pulses (from crankshaft position sensor if DIS system or distributor if not) if it is to activate the fuel pump beyond the fuel system priming stage and to provide spark. Chrysler is not different. Here's what I'd do: 1). Pull fault codes and see what's causing the problems. You may not have any codes stored... 2). Disconnect battery for about 30 seconds and then crank the engine. 3). Pull codes; is code 12 (working from memory here...) present? This code is an "informational" code which states that the engine was not cranked since the battery was last disconnected. No distributor pickup pulses, no cranking evident to the processor ==> code 12. 4). Alternative procedure to see whether distributor pickup signals are present: listen for fuel injector cycling while cranking. *Lack of* *pickup signals will result in no injector activity*. ------------------------------------------------------------------------- It's this last item that got my attention. I can get an exact replacement used engine computer for as cheap as $20 plus shipping from a wrecking yard, but I don't want to start throwing parts at this car again. An ignition module and a fuel filter already cost $55 and the problem still exists. I don't want to throw a computer at it just yet. Bohdan Bodnar goes on to write: ------------------------------------------------------------------------- 5). Suppose your diagnosis suggests that the ECM is not seeing pickup signals. In *my* case, I'd stick an oscilloscope across the pickup and see whether I have a pulse which is not riding on a DC pedestal; i.e., it is switching cleanly between *power* ground and the voltage which is supplied to the Hall Effect pickup in the distributor. If it's riding on a pedestal, I'd locate the poor ground connection and fix it. 6). If a signal is not present, then I'd look at the pickup supply (my recollection is that is 8 volts...could be 5) WITH the pickup disconnected, I'd do a resistance test between the signal ground and power ground. If pickup power and ground are ok, then either the pickup has failed (most likely) or there's a bad electrical connection in the pickup's connector (less likely). ------------------------------------------------------------------------- These last two items suggest a question to me. If the wiring is okay and the distributor is failing to send a signal to the computer, could it still be sending the signal to fire the coil? In other words, if I get spark at the coil wire and barring any wiring problems, would I be getting the proper pickup signal to the computer, also? Then I started wondering what else might cause the computer to fail to fire the injector at startup. And then I started wondering what else might cause the computer to fail to fire the injector at startup, and at other times cause the computer to fire the injector continuously. For $20 plus shipping, maybe it's worth it to throw another computer at it. > If you did the voltage drop test correctly, the ground isn't good, > that's the point of the test. > > No, it indicates an open ground circuit. > [quoted text clipped - 18 lines] > I did a continuity test between the ground wire at the disconnected > computer harness and ground at the battery. It's good. "Continuity test" can mean a whole lot of different things. None of them are adequate for testing the integrity of this circuit. If the ground circuit from the ECM were broken to the point that ALL but one strand of wire was broken, you'd still see continuity as defined but that circuit could in no way flow enough current to allow proper operation. > Don't get pissed but I didn't do the voltage drop test yet. It was a > struggle just to get to the computer, which is now sitting in front of > me. I almost broke something in my back getting it out. If I was going to get pissed because you failed to do a test, I'd have been pissed a week ago because you've skipped many tests recommended. You still haven't measured fuel pressure. > Earlier, when the injector was not spraying gas while cranking, I hooked > up a #194 bulb to the wiring harness for the injector like you said and [quoted text clipped - 4 lines] > the off position. Then I checked the signal wire from the injector > harness for continuity to the computer harness and it was continuous. Again, a continuity test is worthless. One strand of wire will show continuity, but it will not flow the more then 1 amp of current it takes to open the injector. (remember, this is a peak/hold injector) > The only conclusion that I could come to was that *at that moment*, > while cranking the engine, the computer was not grounding the injector [quoted text clipped - 9 lines] > > Bohdan Bodnar wrote: Smart man, his presence on usenet is sorely missed. > Let's go to the fundamentals before troubleshooting. On EVERY EFI > engine, the computer expects to see pickup pulses (from crankshaft [quoted text clipped - 44 lines] > the distributor is failing to send a signal to the computer, could it > still be sending the signal to fire the coil? No. If there is spark, there is a reference signal available at the ECM to trigger the injector. > In other words, if I get > spark at the coil wire and barring any wiring problems, would I be > getting the proper pickup signal to the computer, also? Yes, the proper signal is there. > Then I started wondering what else might cause the computer to fail to > fire the injector at startup. I already listed those things way back. TPS voltage too high, coolant temperature sensor voltage too low... > And then I started wondering what else might cause the computer to fail > to fire the injector at startup, and at other times cause the computer > to fire the injector continuously. > > For $20 plus shipping, maybe it's worth it to throw another computer at it. Not until you properly test the power feeds and grounds. > > If you did the voltage drop test correctly, the ground isn't good, > > that's the point of the test. >>> No, it indicates an open ground circuit. >> Yes! of course! what was I thinking (smacks forehead) [quoted text clipped - 22 lines] > that circuit could in no way flow enough current to allow proper > operation. Then I'll do the test as you outlined it. > >> Don't get pissed but I didn't do the voltage drop test yet. It was a [quoted text clipped - 4 lines] > been pissed a week ago because you've skipped many tests recommended. > You still haven't measured fuel pressure. I don't have the equipment to measure fuel pressure at this time. However, the fuel pump has been working flawlessly in this vehicle for about three years. And while a fuel pump that was providing twice the pressure needed would not cause the injector not to fire. And wouldn't the pressure regulator, do a degree, take care of the excess pressure caused by a fuel pump that put out too much pressure? Besides, the other fuel pump that goes on this vehicle, the one for multi-port injection is mounted outside the tank, not inside, like the one for single point injection, so it could not be possible to install the other FP for this vehicle. So all these factors combined, but mostly the one about not having the equipment, have forestalled a measurement of the fuel pressure. I am not adverse to any procedure. In fact, I would love to be able to have an O-scope and other devices to play with, but I am just a humble shadetree mechanic making due with paper clips and the cheapest DVOM money can buy. > >> Earlier, when the injector was not spraying gas while cranking, I hooked [quoted text clipped - 77 lines] > No. If there is spark, there is a reference signal available at the ECM > to trigger the injector. Good. I appreciate your confidence on this point. I checked and the coil is firing. But the wiring carrying the reference signal from the distributor to the computer could be bad, so I can't yet rule this out. >> In other words, if I get >> spark at the coil wire and barring any wiring problems, would I be [quoted text clipped - 7 lines] > I already listed those things way back. TPS voltage too high, coolant > temperature sensor voltage too low... Let me see if I understand this correctly. If the TPS voltage is too high, the computer responds with a clear flood command and ceases to ground the injector circuit. I can understand this. If I understand the operation of the CTS, high voltage indicates low temperature. How could this cause the computer to *completely* cease grounding of the injector? > >> And then I started wondering what else might cause the computer to fail [quoted text clipped - 4 lines] > > Not until you properly test the power feeds and grounds. Okay... backprobing the ground wire at the computer with the red lead of DVOM and with the black lead at battery negative, run the KOEO test. Voltage should be less than .1 volts. I'm working from memory for purpose of responding. Will check your post again before doing the actual test. I will need to review all your posts again to see if I can determine *exactly* what you mean by "properly test the power feeds and grounds". I can use the procedures in the Chilton manual for testing the various sensors and their related circuitry. I will get back here with the results later in the day. > >>> If you did the voltage drop test correctly, the ground isn't good, >>> that's the point of the test. Signature"Forget it, Jake. It's the Internet." >>> No, it indicates an open ground circuit. >> Yes! of course! what was I thinking (smacks forehead) [quoted text clipped - 30 lines] > been pissed a week ago because you've skipped many tests recommended. > You still haven't measured fuel pressure. I just measured static fuel pressure at the outflow nozzle of the fuel filter. The vacuum/pressure gauge that is have is a perfect fit for it. Pressure is right in the middle of specs of 13-17 psi. Pressure holds steady after FP is cut off. To measure the fuel pressure at the FP regulator will require some more ingenuity on my part. The Chilton manual is sketchy on details. It doesn't specify what the fuel pressure should be. I would have to assume that it at or below the specs for the fuel pump. I don't understand why it is necessary to have the gasoline flow into a container. (1/2 hour later) Just rigged up a tee fitting to check pressure regulator. I kept the old fuel filter and connected the fuel line to the throttle body to it. Then I used a plastic tee fitting and some rubber vacuum hose to connect the two filters and a pressure gauge. Pumped up the system and pressure held steady at 14 psi. Five minutes later, it is steady at 13 psi. Just previous to this, the injector began firing again but uncontrolled. I cut the engine off and tried to restart. Injector not firing. > >> Earlier, when the injector was not spraying gas while cranking, I hooked [quoted text clipped - 100 lines] >>> If you did the voltage drop test correctly, the ground isn't good, >>> that's the point of the test. Signature"Forget it, Jake. It's the Internet." >> The check engine light hasn't come on while the engine was running since >> I started this project. [quoted text clipped - 15 lines] > > Then do a "Key On Engine Running" self test. Record the codes. Will do at the first opportunity tomorrow. The Chilton manual spells out the procedure for doing this with an analog meter. I've done this in the past so it should be a piece of cake. > >> As for the sensor values, I can check them with a DVOM. The TPS checked [quoted text clipped - 3 lines] > > An open Engine Coolant Temperature sensor certainly would. Then I'll add that to the list of things to check. I had a malfunction of the CTS on my 87 Dakota but the carb is no longer the feedback variety and the only thing the computer controls is the engine timing, and that stayed retarded because the computer never saw the engine as warmed up. Either that or the computer was in open loop mode. Either way, the gas mileage sucked and it nearly doubled on the freeway when I fixed the problem. The plastic wiring connector plug was broken and the circuit was open. >> As this is a single injector throttle body system, I don't believe there >> is an Idle Air Control Valve > > It probably has an Idle Speed Control motor, an external device that > pushes against the throttle linkage much like the early GM CCC carbed > cars used. That's exactly what it has: 1989 Ford Escort Idle Speed Control Actuator http://www.google.com/products?q=%22idle+speed+control%22+1989+escort&btnG=Searc h+Products&hl=en&show=dd http://info.rockauto.com/Airtex/Detail.html?2H1455.jpg > I will now re-boot into Windoze, log onto MOD and verify. MOD? > > I will now re-boot into Windoze, log onto MOD and verify. > > MOD? Mitchell On Demand >>> I will now re-boot into Windoze, log onto MOD and verify. >> MOD? > > Mitchell On Demand The fuel injector failed again to shoot gas. Confirmed that the fuel pump was working by taken the cover off the fuel pump regulator and grounding the FP wire in the test plug. Gas shot out the appropriate orifice of the FP regulator. No way to test pressure except with finger. I could feel it pulse against my finger when held tight enough to block the flow and grounding and ungrounding the test wire. Next I confirmed that the injector solenoid was working by giving it 12 volts from the battery. I could hear it click. Tried three times without success to get the injector to shoot gas and then discovered the adjusting screw in the pressure regulator cover. First I screwed in all the way up from inside the cover (it was capped on top), put everything back together and no gas. Then I realized that I needed to *increase* pressure and screwed it back down to where it was originally. Still no gas. The I screwed it down another 1/8 of an inch or so (that's the smallest unit some carpenters will work to) to increase the pressure and put it back together, grounded the fuel pump for a few seconds and then fire the injector off the battery and got gas. Put everything back together and started the engine, which was pouring black smoke out the exhaust like it does when it's bad, but it was good enough to get it off the street and into the driveway because tomorrow is street sweeping day where I live, and they take your firstborn if you are parked on the street. So now I am getting curious about the fuel pressure in the system and I am beginning to think about how to rig it up so I can see the fuel pressure while driving. The only thing in the fuel pressure regulator that looks like it might need changing is the diaphragm. I still don't understand this flip-flopping back and forth between too much gas and no gas. It could very well be that two different things are going on here. At this point I am open to any suggestions you may have about how to proceed. If it's within my ability, I will do it and report back. Signature"Forget it, Jake. It's the Internet." >>>> I will now re-boot into Windoze, log onto MOD and verify. >>> MOD? [quoted text clipped - 37 lines] > At this point I am open to any suggestions you may have about how to > proceed. If it's within my ability, I will do it and report back. When there was no fuel being injected did it set any codes ? When there was no fuel being injected did you test for injector pulse ? When there was no fuel being injected did you check for power to the fuel injector ? >>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>> MOD? [quoted text clipped - 39 lines] > no fuel being injected did you test for injector pulse ? When there was no > fuel being injected did you check for power to the fuel injector ? Mike, 1. Just checked. It set code 95, 'Fuel pump secondary circuit failure'. 2. No, and therein may lie something. Would a digital dwell meter help in that regard? 3. No, but fuel pump never failed to run when it should, based on sound. I could hear it whirring. Signature"Forget it, Jake. It's the Internet." >>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>> MOD? [quoted text clipped - 51 lines] > 3. No, but fuel pump never failed to run when it should, based on sound. I > could hear it whirring. If the fuel pump never failed to run I would ignore the code 95 for now. You can check for injector pulse with with a simple test light. I would suggest a digital VOM be used to check for the proper voltage to the injector. >>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>> MOD? [quoted text clipped - 55 lines] > You can check for injector pulse with with a simple test light. I would > suggest a digital VOM be used to check for the proper voltage to the injector. Mike, I used the duty cycle function on the DVOM to check the signal to the injector and got a 2.0 reading at idle that increase to between 3.0 and 4.0 with a slight jab to the accelerator. Fuel pump is whirring when it should, when key is turned to the on position and when the running engine is turned off. The problem as it is being manifested at present is an overly rich mix at idle that causes rough idle and black smoke and water out the tailpipe. Adjusting the pressure regulator does not visually affect the flow of gas from the injector. Also, from a newly cleared computer, with about 20 to 30 seconds of idle and one or two revs and then shut down, I got code 32, 'EGR valve not seated'. I don't know what condition sets this code. There are no wires to the EGR valve so I don't know how the computer sense that the valve is not seated. So I am getting this alternation between too much gas, no gas and just right. It's like Goldilocks and the Three Bears. Just to be sure, I am going to pull the EGR valve right now and check it. But I am getting increasingly suspicious of the injector as being the component that, if malfunctioning, might cause these three conditions of too much, too little and just right fuel flow. BTW... how do you test pulse width with a test light? Do you mean a 'noid'? I don't have one, but I have the duty cycle function on the DVOM, which I bought to check the fuel mixture solenoid... oh, that's where 'noid' comes from. (light goes on). I'll get back here after I check the EGR valve. >>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>>> MOD? [quoted text clipped - 84 lines] > > BTW... how do you test pulse width with a test light? You don't. You only need to see if the computer is suppling a ground and if you have power on the other wire. If both conditions are met the test light flashes. Do you mean a > 'noid'? I don't have one, but I have the duty cycle function on the DVOM, > which I bought to check the fuel mixture solenoid... oh, that's where 'noid' > comes from. (light goes on). > > I'll get back here after I check the EGR valve. >>>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>>>> MOD? [quoted text clipped - 87 lines] > you have power on the other wire. If both conditions are met the test light > flashes. The test light didn't flash and the I have power to the red wire at the injector harness. I am convinced that the computer is not grounding the signal wire. The only question that remains is 'why not?' Possible reasons: 1. Faulty computer 2. Some other faulty component(s) that is causing the computer not to ground the injector circuit. 3. Faulty wiring in the injector circuit. I just ruled out number 3 by directly connecting the injector signal wire to the ground wire at the disconnected computer harness. With the injector harness disconnected I turned the key to 'on' and then reconnected the injector harness. The solenoid inside the injector clicked with each connect and disconnect. So using the actual wires in the injector circuit, I can get the injector to fire. As far as number 2 goes, I believe I can rule out the TPS by simply disconnecting it. If the TPS or it's circuitry is faulty, the computer should step in to supply the missing value and the injector should fire at startup. If the injector fires at startup with the TPS disconnected and doesn't fire at startup with the TPS connected, then the TPS or its circuitry could be faulty. Staying with number 2, the wiring that supplies the computer with pickup signals from the distributor may be faulty. The coil fires when cranking, so that part is okay. I'm sure there are huge gaps in my knowledge of computer controlled fuel injection. I can't think of any other input to the computer that would cause it to completely cease firing the injector at startup, but those are the ones I want to concentrate on. > Do you mean a >> 'noid'? I don't have one, but I have the duty cycle function on the DVOM, >> which I bought to check the fuel mixture solenoid... oh, that's where 'noid' >> comes from. (light goes on). >> >> I'll get back here after I check the EGR valve. >>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>> MOD? [quoted text clipped - 55 lines] > You can check for injector pulse with with a simple test light. I would > suggest a digital VOM be used to check for the proper voltage to the injector. I just hooked up a #194 bulb to the injector wiring, like aarcuda suggested, and found that, at present, there is no grounding of the circuit. 12 volts is present at the hot, but there is no path to ground. The system is back in the 'no gas at all' mode. This narrows the problem somewhat, but I still can't imagine what would cause an all or nothing condition as far as the grounding of the signal wire to the injector goes. Just this morning gas was pouring out of the injector at idle. It's as if the signal wire from the injector to the computer is open and sometimes it gets grounded out. Except that sometimes, on rare occasions the car seems normal. So the problem *has* to lie either with the wiring or the computer. Unfortunately, the computer was designed into the most inaccessible place imaginable, the upper driver's side, behind the dash. Signature"Forget it, Jake. It's the Internet." >>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>>> MOD? [quoted text clipped - 71 lines] > Unfortunately, the computer was designed into the most inaccessible > place imaginable, the upper driver's side, behind the dash. Wiring checks out okay from injector plug to computer plug for injector signal wire. If there is no other condition that would cause the computer *not* to fire the injector at startup, then I can arrive at no other conclusion except that the computer is on the fritz. Just looked in the Chilton manual and the procedure they have for troubleshooting the injectoris as follows: 5. If the injector is not spraying fuel, unplug the electrical connector from the injector. 6. Attach a noid light to the injector electrical harness and have an assistant crank the engine. (I used a #193 bulb as per aarcuda) 7. If the noid light operates, replace the injector. (it didn't) 8. If the noid light does not operate, check the injector wiring harness for damage and repair as necessary. If the noid light still does not operate, Check the Throttle Position sensor and it's circuit. So I guess I need to check the TPS before jumping to the conclusion that the puter is bad. I checked the TPS earlier, but I didn't check the wiring. Time to get back at it. Signature"Forget it, Jake. It's the Internet." >>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>>> MOD? [quoted text clipped - 62 lines] > is present at the hot, but there is no path to ground. The system is back in > the 'no gas at all' mode. That should have been one of the first tests you performed when it wouldn't start. > This narrows the problem somewhat, but I still can't imagine what would > cause an all or nothing condition as far as the grounding of the signal wire > to the injector goes. Just this morning gas was pouring out of the injector > at idle. It's as if the signal wire from the injector to the computer is > open and sometimes it gets grounded out. Except that sometimes, on rare > occasions the car seems normal. The computer fires the injector by supplying a ground. > So the problem *has* to lie either with the wiring or the computer. > Unfortunately, the computer was designed into the most inaccessible place > imaginable, the upper driver's side, behind the dash. Well, the computer needs some sort of signal to tell it when to fire the injector, right ? So it could also be a bad cam or crank sensor. When you lose injector pulse do you lose spark also ? > "Forget it, Jake. It's the Internet." >>>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>>>> MOD? [quoted text clipped - 81 lines] > injector, right ? So it could also be a bad cam or crank sensor. When you > lose injector pulse do you lose spark also ? No, I check last night and spark was strong and bright. If the problem is with the distributor pickup signal not reaching the computer, it has to be with the wiring. This is a single injector in a throttle body so the signal comes from the pickup on the distributor. The Chilton manual I have shows four wires going from the distributor into the computer. All I can do is check them all for continuity. If they all check out, I will assume that the computer is getting the signal it needs. I have to work with the tools I have and make the most of them. >> "Forget it, Jake. It's the Internet." Signature"Forget it, Jake. It's the Internet." >>>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>>>>> MOD? [quoted text clipped - 81 lines] > injector, right ? So it could also be a bad cam or crank sensor. When you > lose injector pulse do you lose spark also ? To add to my last post, I just checked all the wiring from the distributor to the computer and all four wires check good for continuity. I am getting spark at the coil so I will assume for now that I am getting pickup signal to the computer. One wire has an 'ignition suppressor resistor' in series between the distributor and the computer and it reads 22,000 ohms. So now I want to check the TPS. Mike, if you know of any other conditions outside of a faulty computer that might result in no grounding of the fuel injector when the engine is cranked, please, by all means post them. Here's what I know with a very high degree of certainty. 1. The injector works. 2. The fuel pump and pressure regulator are working. 3. There is no voltage to the injector at startup. 4. The injector wiring is sound. 5. The distributor wiring to the computer is sound and I am getting spark at the coil. 6. The wiring from the TPS and the MAP sensor to the computer is intact. 7. Disconnecting the TPS and MAP sensors does not enable the injector. I may be wrong, but with my limited knowledge I can only conclude from this that the TPS and MAP sensors do not play a part in the failure of the computer to ground the injector circuit. I am looking at a *complete* failure of the grounding of the injector at startup. Nada, zero, zilch. I have managed, to my satisfaction, to eliminate all known (to me) possibilities that might cause this problem with the exception of the computer. If the computer is good, If there is proper fuel pressure to the injector, If the injector and its circuitry are good, If the coil is firing and the wiring from the distributor to the computer is intact, If the MAP, TP, ECT, ACT and O2 sensors are disconnected, Then the computer should be grounding the injector circuit at startup. From everything that I know so far, the computer is faulty OR Something that I don't see is interfering with the computer's ability to ground the injector at startup. I have been adding to this post all morning. See the one just previous to this one to aarcuda it has the very latest. > >>>>>>> In article <pnBJj.198$v...@newssvr21.news.prodigy.net>, > [quoted text clipped - 151 lines] > I have been adding to this post all morning. See the one just previous > to this one to aarcuda it has the very latest. Only thing I can add is make sure the puter has a good solid ground. I suspect that it does otherwise you'd have more issues, but it's easy enough to check - run a test lead from the puter case to a known good ground and try again. nate >>>>>>>>> In article <pnBJj.198$v...@newssvr21.news.prodigy.net>, >>>>>>>>>>> I will now re-boot into Windoze, log onto MOD and verify. [quoted text clipped - 137 lines] > > nate Thanks nate, I used two different tests to confirm good ground. I fired the injector through the computer wiring harness while it was unhooked from the puter. I shorted the injector signal wire directly to the ground wire in the puter harness and turn the key on. The injector fired. Then I ran aarcuda's test of backprobing the ground wire with the positive lead of a digital volt meter while connected the negative lead to battery ground while the harness was connected to the puter and then running the KOEO test to check for any voltage drop. There was none. Now I'm waiting for the battery to recharge enough to continue. Signature"Forget it, Jake. It's the Internet." >>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>> MOD? [quoted text clipped - 39 lines] > no fuel being injected did you test for injector pulse ? When there was no > fuel being injected did you check for power to the fuel injector ? Mike, did a search for 'Fuel pump secondary circuit failure' and found this: http://www.fordmuscle.com/forums/all-ford-techboard/466783-fuel-pump-secondary-c ircuit-failure.html Here is the google search for that phrase: http://www.google.com/search?hl=en&q=%22Fuel+pump+secondary+circuit+failure%22&b tnG=Google+Search Signature"Forget it, Jake. It's the Internet." >>>>>> I will now re-boot into Windoze, log onto MOD and verify. >>>>> MOD? [quoted text clipped - 47 lines] > > http://www.google.com/search?hl=en&q=%22Fuel+pump+secondary+circuit+failure%22&b tnG=Google+Search The second link on that google search leads to a list of the codes and 95 sounds a lot like what aarcuda69062 mentioned about grounding issues: "One last item; these vintages of Ford products were lousy for EEC ground problems. Since the EEC self tests by design activate certain EEC components, the self test is a good time to voltage drop the ground circuit between the ECM and battery negative." Time to get bizay? Signature"Forget it, Jake. It's the Internet." And thanks to all for the help... Components that I know or feel strongly are good... and why 1. *Fuel Pump and Fuel Pressure Regulator* Both work to keep fuel pressure within specs, 13 to 17 psi, after brief cranking for the alloted time of 60 seconds. 2. *Fuel Injector* The fuel injector will spray fuel continuously when hooked up to the battery, and fuel pressure is maintained. 3. *Fuel Injector Wiring* Fuel injector works as described above when the current is routed through the fuel injector wiring that is used by the computer. With the wiring harness disconnected from the computer and the injector signal wire shorted to the ground wire at the plug and using the red +12 volt wire to the injector, when the key is turn on, the injector fires. 4. *Wiring from the Distributor to the Computer* These wires were tested for continuity with a a digital ohm meter and found to be intact. The coil is firing a strong spark when the engine is cranked. 5. *Computer Ground Circuit* This circuit was tested by backprobing the ground wire at the computer with the positive lead of a digital volt meter and attaching the negative lead to battery ground and running the KOEO test. There was no voltage drop. The procedure in #3 confirms that the computer grounding circuit is good. 6. *Throttle Position Sensor* I checked the TPS as per the Chilton manual with the following results: VREF = 5 volts Voltage range was from .76 volts at fully closed to almost 5 volts at full opened, measuring across the appropriate terminals. The TPS wiring to the computer is intact as measured by a digital ohm meter. 7. *EGR Valve* I removed and inspected the EGR valve. It moves freely when 5 to 10 pounds of vacuum is applied. All vacuum lines are intact. I did *not* yet check the valve that opens the vacuum line to the EGR valve as the engine warms up. 8. *MAP Sensor Wiring* The MAP sensor wiring to the computer is intact as measured by a digital ohm meter. I have yet to test the MAP sensor itself. Today, at different times, the injector both fired and did not fire when cranking the engine. At one point I used a #194 bulb to check the injector harness and the bulb pulsed as the engine was cranked. At another time the injector was hooked up as I cranked the engine and the engine started, albeit with a heavily rich mixture. But mostly the injector would not fire when the engine was cranked. After going through all this, I pulled codes and found that the computer set Code 95 again, 'Fuel pump secondary circuit failure', although the fuel pump worked flawlessly when grounded through the FP test terminal at the test socket, and when turning the key on and turning it off, the latter only if pressure below a certain level. Things I should check: MAP sensor values Coolant temp sensor values Fuel pump relay At this point, even though they rarely fail, I am becoming very suspicious of the computer. But before I take that step I want to exhaust all other possible causes so please feel free to add to the list. I notice on the wiring diagram for the computer that an 'EGR vacuum regulator' is hooked up to the computer. It appears to be an electromagnetic solenoid, but it's function is unclear. Just looked it up. It is analogous to the EGR port on a carb. Basically tells the EGR valve when to open. Appropriately named. I don't know how this computer is programmed to control gas flow through the injector and how any given failure in any given sensor or component might cause the computer to shut down gas flow by ceasing to ground the injector. aarcuda explained how malfunction of the TPS could cause the computer to issue a 'clear flood' command at idle which would shut down the injector, but the TPS sensor and its circuitry tests out okay. > And thanks to all for the help... > [quoted text clipped - 80 lines] > computer to issue a 'clear flood' command at idle which would shut down > the injector, but the TPS sensor and its circuitry tests out okay. Make sure the ecm is getting a pip signal. |
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