 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Volvo Cars / July 2006'87 760 (B230FT) Injector Test
I have a no start problem that I believe is a fuel issue. I have checked everything up to the injector rail and I need some help with diagnosis. I could hear nothing with the screwdriver to the injector clicking noise test while the engine was being cranked. I checked the resistance on the injectors and they are all reading 2.7 ohms. According to Chilton etc they should read 16 ohms but I have a hard time believing all four injectors died at once. I confirmed a connection between the fuel rail grounds and battery "-". I can smell a little gas at the fuel pressure regulator vacuum hose but I have not read anything that indicated this could cause a complete no start problem. Thanks in advance for any help. >I have a no start problem that I believe is a fuel issue. I have > checked everything up to the injector rail and I need some help with [quoted text clipped - 8 lines] > problem. > Thanks in advance for any help. I am understanding you have determined you have good pressure at the rail. Have you checked for spark? If that is missing, the Hall sensor may have died... without the signal from that, the injectors never fire. I suspect the 16 ohm reading includes the ballast resistors or is for the non-turbo injectors. My B230FT injectors measure about 2.5 ohms. With just one injector disconnected I read about 5 ohms to ground on one side of the connector and about 7 ohms to ground on the other side. Mike > I have a no start problem that I believe is a fuel issue. I have > checked everything up to the injector rail and I need some help with [quoted text clipped - 8 lines] > problem. > Thanks in advance for any help. On an YM87 2.7 Ohms is correct for blue top injectors (aluminum low resistance quick acting). If you were to measure the resisitance between the injector wire pairs at the control unit you would see ~4 Ohms since the resistance from the resistor pack in the turbo harness would be added in. If you get no flash from the power wire to the injector while cranking then either the computer has died, the harness is bad or there is no spark. If you have fuel pressure at the rail and the fuel pump runs while cranking then you have spark. Bob  SignatureThe goal when driving is to miss the maximum number of objects. Thanks for the responses. I have verified there is fuel in the rail. I believe there is spark because starter fluid in the air intake will cause the engine to start for an instant. I think the problem is that the injectors are not getting a pulse. I determined this by plugging a voltmeter into the back of an injector plug and watching for any sign of voltage when I crank the engine. here was none. Does this test make sense? I have already checked what I could on the ECU using the Chilton information and according to the guidelines the system grounds, air mas meter and coolant temp sensor are okay. The throttle switch test failed at the full throttle position but passed at the idle position. I also checked the air mass meter at the meter itself. There was no mention of a check for injector control on the ECU. > > I have a no start problem that I believe is a fuel issue. I have > > checked everything up to the injector rail and I need some help with [quoted text clipped - 19 lines] > > Bob > Thanks for the responses. > [quoted text clipped - 11 lines] > checked the air mass meter at the meter itself. There was no mention of > a check for injector control on the ECU. Look for the injector resistor pack, it's on the inner fender near the front of the car. Verify no broken wires and clean the connections. Believe it or not, this part does not use waterproof terminals. Also look for a black relay with 4 round pins on or near one of the shock towers. This relay supplies power to the injectors. SignatureMike F. Thornhill (near Toronto), Ont. Replace tt with t (twice!) and remove parentheses to email me directly. (But I check the newsgroup more often than this email address.) Thanks again for the help. I believe I ohmed out the resistor pack a while back and it was okay but I will check it again. Is the black relay you are referring to the radio suppression relay? I encountered some confusion regarding this earlier. I have a black relay on the driver's side near the shock tower but I came to the conclusion after some research this is not a "feature" on the '87 turbos. Do you agree? If not, the literature I encountered indicated that I should swap this with the electric fan relay but I could not find a second relay. Do you have any idea where I should look for the identical fan relay? Some the diagrams I have seen include inline fuses for the injection system that are under the hood. I have not seens any references to these in trouble shooting tips so I have avoiding them. Any chance they could be the problem? > > Thanks for the responses. > > [quoted text clipped - 25 lines] > Replace tt with t (twice!) and remove parentheses to email me directly. > (But I check the newsgroup more often than this email address.) > Thanks again for the help. > [quoted text clipped - 40 lines] > > Mike F. > > Thornhill (near Toronto), Ont. YM87 only had the radio suppression (injector) relay under the hood by the PS reservoir bottle. The cooling fan relay was a five pin type in the central electrical panel behind the ashtray. Bob SignatureThe goal when driving is to miss the maximum number of objects. > YM87 only had the radio suppression (injector) relay under the hood by > the PS reservoir bottle. The cooling fan relay was a five pin type in [quoted text clipped - 3 lines] > -- > The goal when driving is to miss the maximum number of objects. Right. And the suppression relay was something they added part way through the year, and as an free update (recall?) to ones (and 85 and 86 model years) that had already been sold. This is why it may not show in all literature and manuals. This poorly named relay is called (by Volvo) the radio suppression relay. What is does is supply power directly from the battery to components that require pulsing (on-off) power - like the injectors. This isolates this "noise" from the supply to the radio, thus "suppressing" interference. SignatureMike F. Thornhill (near Toronto), Ont. Replace tt with t (twice!) and remove parentheses to email me directly. (But I check the newsgroup more often than this email address.) This is great info. Things are starting to make sense. I only have the relay by the driver side shock tower but it has the correct part number so unless there is another use for that relay I will assume it could be the culprit. Any suggestions on testing or should I just replace it? Any ideas on where I could find one? > > YM87 only had the radio suppression (injector) relay under the hood by > > the PS reservoir bottle. The cooling fan relay was a five pin type in [quoted text clipped - 21 lines] > Replace tt with t (twice!) and remove parentheses to email me directly. > (But I check the newsgroup more often than this email address.) > This is great info. Things are starting to make sense. > I only have the relay by the driver side shock tower but it has the > correct part number so unless there is another use for that relay I > will assume it could be the culprit. > Any suggestions on testing or should I just replace it? > Any ideas on where I could find one? That relay sends power to the resistor pack. There's one wire at the resistor pack that is connected to all 4 resistors. The other 4 wires go to the injectors. The other wires at the injectors are grounded by the FI computer, which is what opens the fuel path. Check for power at the resistor pack. SignatureMike F. Thornhill (near Toronto), Ont. Replace tt with t (twice!) and remove parentheses to email me directly. (But I check the newsgroup more often than this email address.) The problem was the wire that inputs the voltage to the resistor pack was broken inside the plastic resistor pack connector. I found it when I went to clip a volt meter to the line to see if anything was coming out of the radio suppression relay. I picked up two spare resistor packs in good shape and a couple relays just in case at a salvage yard for $21. Replaced the resistor pack and used my original relay and it started right up. Thanks for the all the help. > > This is great info. Things are starting to make sense. > > I only have the relay by the driver side shock tower but it has the [quoted text clipped - 15 lines] > Replace tt with t (twice!) and remove parentheses to email me directly. > (But I check the newsgroup more often than this email address.) |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.