Car Forum / Audi Cars / January 2005
Driving with disconnected ISV?
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Yvan - 21 Oct 2004 07:55 GMT I have hmmm... dual fueled 1989 Audi 100 2.3E (NF 5-Cyl. engine). I start engine on unleaded petrol, and after few minutes ('till engine warms up) it switches to LPG (see http://www.lpga.co.uk/LPGA.htm). It is LPG system of an older generation without lambda (O2) gas control.
When I stop the car rpm drops to some 500-600 and then sometimes stalls, and sometimes goes up to 900-1000 and then back to standard 750.
I was wondering if I can disconnect ISV or switch that goes on when throttle pedal is released (I can not remember it's name, English is not my native language), switch that activates ISV. Does that switch do something else? Could i do any damage by disabling it? Or by disconnecting ISV?
On LPG system I can adjust idle by turning a knob, but it seems that ISV is slow in reaction when throttle pedal is released, so to confirm that I want to try driving with ISV disconnected, but I am afraid of possible damage to other systems.
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Steve Sears - 21 Oct 2004 15:48 GMT Yvan, I must admit I have no knowledge of the LPG system or how it runs. With a normal engine, the throttle switch tells the idle stabilization system when the throttle is at idle, and the ISV should regulate rpm. It sounds like you have a sticky ISV - which you should clean with _throttlebody cleaner_ (NOT CARBURETOR CLEANER), or check the condition of the throttle switch. If the ISV is a 2 contact unit, if you can blow through the unit (after it's cleaned, of course) without power, then it's no good. If it's a 3 contact unit, then it is supposed to allow air through at rest. When you clean the ISV, use a 9volt battery to make the valve click to ensure that it is not siezed. If the LPG system acts like a normal fuel system, the shutdown of the switch or of the ISV shouldn't harm it, it will just idle poorly. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> I have hmmm... dual fueled 1989 Audi 100 2.3E (NF 5-Cyl. engine). I > start engine on unleaded petrol, and after few minutes ('till engine [quoted text clipped - 14 lines] > I want to try driving with ISV disconnected, but I am afraid of possible > damage to other systems. Yvan - 21 Oct 2004 19:46 GMT Nedavno Steve Sears pise:
| It sounds like you have a sticky ISV - which you should clean with | _throttlebody cleaner_(NOT CARBURETOR CLEANER), or check the condition | of the throttle switch. Throttle switch is OK it goes on just when it is suppose to, and I cleaned ISV with carburetor cleaner :-( and 9 V battery. Everything works OK running on petrol, it's LPG that is troubling me.
Hire is in short how it works: Engine is always started on petrol, and runs on petrol for few minutes, until engine warms up. Then it switches to LPG. LPG is in liquid state in tank, goes to evaporator (warmed with coolant from car cooling system so it does not freeze), and there it evaporates and goes into intake mainfold trough rubber hose. When engine idles LPG is going trough ISV. So all the electronic, O2 sensor... have no effect when engine is running on LPG. Sort of very simple carburetor. Only thing that can be adjusted is idle (with a knob on evaporator). Since ISV is constantly working I have trouble adjusting idle so I try to disconnect it but engine died. So it seems that my idea about running engine with ISV disconnected is no good :-)
| If the ISV is a 2 contact unit, if you can | blow through the unit (after it's cleaned, of course) without power, | then it's no good. It's 2 contact unit, I'll try that.
| If it's a 3 contact unit, then it is supposed to | allow air through at rest. When you clean the ISV, use a 9volt | battery to make the valve click to ensure that it is not siezed. Did that while I was cleaning ISV, it is working. I also did the test by inserting fuse in one of relay's in fuse box for few seconds, and than by activating full throttle switch, and it's clicking.
| If the LPG system acts like a normal fuel system, the shutdown of the | switch or of the ISV shouldn't harm it, it will just idle poorly. As I said it does, so much for my idea.
BTW how do you adjust timing on this car, how do you loosen distributor when there is bolt at it's base?
I hope you can understand what I am writing, my English is far from perfect, and I still have to learn all mechanic words :-)
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Steve Sears - 21 Oct 2004 21:01 GMT Yvan, Although I can't vouch for this, I have heard that you cannot adjust timing by turning the distributor - as I understand it (or misunderstand it), the crank position sensor (a magnetic sensor which picks up the passing of a timing pin on the flywheel) tells the engine control unit when the engine is at top dead center for cylinder 1, and the engine is run accordingly using the hall sensor in the distributor as a secondary reference. Somebody...help me out on this one..... When you say that LPG is going through the ISV - is the LPG hose connected to the valve itself, or the intake? The ISV in a normal car acts like a controllable vacuum leak to stabilize the rpm of the car by controlling the rise and fall of the metering plate - more vacuum in the manifold ~ plate rises ~ more gas injected ~ rpm increases. The ISV is designed to leak unmetered (and unexplosive) air into the engine to drop the plate - if you have the LPG connected to the ISV so it is leaking explosive LPG.....hmmm. This might explain how disconnecting the ISV will result in the engine dying - when the power to the ISV is shut off, the ISV is shut off (or almost off if it is leaking) - so no LPG to the engine. If sounds to me like the change in function of the ISV (from a vacuum leak to a fuel injector) might be the problem with the oscillating idle - when it opens up, it is expecting to let in more air which would normally drop the metering plate and reduce the idle - but in this case the opening of the ISV results in more fuel (LPG) into the engine.....is this right? Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> Nedavno Steve Sears pise: > [quoted text clipped - 42 lines] > I hope you can understand what I am writing, my English is far from > perfect, and I still have to learn all mechanic words :-) Yvan - 22 Oct 2004 20:32 GMT Nedavno Steve Sears pise:
| Yvan, | Although I can't vouch for this, I have heard that you cannot adjust [quoted text clipped - 4 lines] | the engine is run accordingly using the hall sensor in the distributor | as a secondary reference. Somebody...help me out on this one..... OK, I was just wondering... Thanks.
| When you say that LPG is going through the ISV - is the LPG hose | connected to the valve itself, or the intake? LPG hose (actually two of them - one for idle, and one for all but not idle - sorry for mu bad English again) is connected to air/fuel mixer located in front of intake. From air/fuel mixer one hose is going to angled elbow and from there one small hose to intake, and one bigger to ISV.
| The ISV in a normal car | acts like a controllable vacuum leak to stabilize the rpm of the car [quoted text clipped - 11 lines] | plate and reduce the idle - but in this case the opening of the ISV | results in more fuel (LPG) into the engine.....is this right? I think that hose that is going to the ISV delivers LPG/air mixture, not just pure LPG.
I was wrong when posting my original post stating that engine works OK on unleaded fuel. Today since my engine stalled almost every time I stopped in on red traffic light, I switched back to gasoline, and engine then did not die, but it goes to some 650-700 rpm, shakes, then goes to 800-850 rpm and than back to 750 that it should be idling.
So since timing can not be adjusted, and I changed spark plugs, I should probably change distributer cap, rotating arm in distributer. Can O2 sensor give that symptoms? I tested it and it oscillates 0.35 V (.17 up an d .17 down) but it takes 1.2 sec (should be .3 sec). I am not willing to change it, because I think that it has no role when driving on LPG (I am not sure about that). Also where I live monthly income is low, (I as a system administrator in a firm with 500 employees make 300$ for a month) so I am trying to do repairs myself, and Audi part prices are the same or higher than in US. I could sell this car, but I love it so much it is good and served me well for 6 years, I just have to fix this idle thing.
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Steve Sears - 22 Oct 2004 22:11 GMT Yvan, If the ISV is delivering a mixture of LPG and air, that is still more burnable than the air it is supposed to deliver. The ISV is usually opened to drop the metering plate to reduce the amount of fuel going into the engine - but when your ISV opens, it is letting more LPG into the engine. It sounds backwards to me. I would change the cap and rotor as a maintenance item, but if the original oxygen sensor is still in the car I would consider changing it - doubly so if the convertion to LPG used any silicone sealants to seal the hose connections (silicone will coat the OXS). If you can get a cheap price on _any_ 3-wire oxygen sensor, I would get one and splice it into the Audi harness, or get to know some local Audi owners and borrow one to see if the change changes anything - get togethers at pubs are helpful - the flow of beer seems to increase the loaning of tools and selling of spare parts for less money ;-) Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> I think that hose that is going to the ISV delivers LPG/air mixture, not > just pure LPG. [quoted text clipped - 16 lines] > it is good and served me well for 6 years, I just have to fix this idle > thing. Yvan - 23 Oct 2004 09:39 GMT Nedavno Steve Sears pise:
| If the ISV is delivering a mixture of LPG and air, that is still more | burnable than the air it is supposed to deliver. Yes, but since there is no gasoline it must be LPG-air mixture.
| The ISV is usually | opened to drop the metering plate to reduce the amount of fuel going [quoted text clipped - 4 lines] | it - doubly so if the convertion to LPG used any silicone sealants to | seal the hose connections (silicone will coat the OXS). Yes there is some red stuff that looks like silicone sealant where air/LPG mixer is located. I just wonder if it is necessary. Does O2 sensor have any influence on anything else but amount of injected fuel? If not I would be changing it for nothing since I drive 99% of time on LPG. I tried to disconnect it, but it seems to have no effect on idling whether engine is on LPG or gasoline. But it's definitely not working as it should I tested it by some instructions provided by Bosch with oscilloscope.
| If you can | get a cheap price on_any_ 3-wire oxygen sensor, I would get one and | splice it into the Audi harness, or get to know some local Audi owners | and borrow one to see if the change changes anything - get togethers | at pubs are helpful - the flow of beer seems to increase the loaning | of tools and selling of spare parts for less money ;-) Ha, interesting idea :-) If you think that O2 sensor does have effect on something else than amount of injected fuel I will buy one and replace it. Maybe it will not better things, it certainly will not do any bad.
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Steve Sears - 25 Oct 2004 15:02 GMT Yvan, Ideally, I believe that the LPG go through the main intake _only_ and not also through the ISV.....but I'm sure that the people who designed the system know their stuff. The use of silicone sealant is troublesopme, though. Check out: http://www.sjmautotechnik.com/trouble_shooting/10vo2sen.html The oxygen sensor feeds back to the engine control unit, which does figure in to the idle of the car. Part way down Scott mentions that carbon plugged slots in the OXS will result in fluctuating idle mixture and idle speed. That _may_ be your culprit. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> Nedavno Steve Sears pise: > [quoted text clipped - 31 lines] > something else than amount of injected fuel I will buy one and replace > it. Maybe it will not better things, it certainly will not do any bad. Yvan - 25 Oct 2004 20:11 GMT Nedavno Steve Sears pise:
| Ideally, I believe that the LPG go through the main intake _only_ and | not also through the ISV.....but I'm sure that the people who designed [quoted text clipped - 6 lines] | carbon plugged slots in the OXS will result in fluctuating idle | mixture and idle speed. That _may_ be your culprit. Yes, but disconnecting O2 sensor for a while should solve my problem, and then I could buy new one.
What about deceleration valve? Do I have one? Could stuck decel valve be my problem?
I borrowed one ISV from a guy that sells used Audi parts. He only had one like this:
http://www.sjmautotechnik.com/trouble_shooting/ecupic/idlesta2.jpg which is slightly different then one I have. Borrowed one passed blowing test (as you mentioned it should be closed with no power). Mine did not, but looking at how it operates I am almost sure that that is the way it is suppose to be. With ISV in horizontal position there is a 1 mm gap on the top of a rotating metal thing that can be seen on the "in" side of ISV. With 9V power rotates up first closing mentioned 1 mm gap and then opening gap below it. I hope you can understand this :-)
Anyway, fitting other ISV did not do anything, problem is still hire.
Again I was wondering about decel valve. Perhaps if I have one I could temporarily disable it to see if it is stuck? As I understand it should be somewhere on air filter box. I will check tomorrow (hire is night now) but it would help if I would knew what it looks like.
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Steve Sears - 26 Oct 2004 16:49 GMT Yvan, The system in the 1987 Audi 5000 Turbo/200 used a deceleration valve, the failure of which could result in the engine stalling (it cuts the fuel delivery off to the engine when the car decelerates, thus reducing fuel consumption) - but that is for the fuel system, which your LPG system is not using. There's a Russian web site that has all the parts diagrams - if you ask the collective at www.audifans.com - I'm sure someone will send you the link to the site (it's often referred to as the "Family Album"). I think you should give all of the intake hoses a real close check for cracks or leaks - also in the connections between the LPG system and the car's original system hoses - the underside of the intake hoses rots out first due to oil from the crankcase recirculation (and turbo leaks). When the car is idling, the intake is under a vacuum and may cause an intermittent leak in a broken hose - changing the fuel/LPG mixture and thus the idle. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
Yvan - 26 Oct 2004 20:15 GMT Nedavno Steve Sears pise:
| The system in the 1987 Audi 5000 Turbo/200 used a deceleration valve, | the failure of which could result in the engine stalling (it cuts the | fuel delivery off to the engine when the car decelerates, thus | reducing fuel consumption) - but that is for the fuel system, which | your LPG system is not using. Yes, but from:
http://www.sjmautotechnik.com/trouble_shooting/ecusys.html#decel
"These valves have been known to stick open and then not shut when the RPM drops below 1200 which causes the big vacuum leak and the stalling"
So if deceleration valve is not completely stick, but slow in response (close to sticking, but still works) I would have vacuum leak. I do not knew if this is possible.
| There's a Russian web site that has all | the parts diagrams Yes, I knew, I found it some time ago, its:
http://www.elcats.ru/audivw/nn/
I was searching there and on page:
http://www.elcats.ru/audivw/nn/vag4.asp?gid=1&cid=79&motor=&myear=1988&cyl=&vol=
when you click on nine-th item from the top, and then on the button below the picture on the left, (NF engine) there is no decel valve. But if you click on the eighth item from the top and then on the button below the picture on the left, (MC engine) there is one. So it seems that I do not have one.
What about EGR valve? Where is it? I can not find it either on Russian site. Do I have it? Can that be the problem?
| I think you should give all of the | intake hoses a real close check for cracks or leaks - also in the [quoted text clipped - 3 lines] | the intake is under a vacuum and may cause an intermittent leak in a | broken hose - changing the fuel/LPG mixture and thus the idle. I already checked intake hoses. Only breather hose was broken, and I replaced it.
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Steve Sears - 27 Oct 2004 15:51 GMT Yvan, I think that the oxygen sensor and the catalytic converter led to the demise of the EGR valve - my 1980 5k (WD-code engine) has one (and no OXS or cat. converter), but my 1987 5ktq (MC-code engine) does not. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
Yvan - 27 Oct 2004 19:11 GMT Nedavno Steve Sears piše:
| I think that the oxygen sensor and the catalytic converter led to the | demise of the EGR valve - my 1980 5k (WD-code engine) has one (and no | OXS or cat. converter), but my 1987 5ktq (MC-code engine) does not. Thanks for all your help. I will check once again all the vacuum hoses, maybe replace some of them will ones for fuel or radiator hoses be good? If nothing gets better I'll have admit defeat and go to mechanic :-(
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Steve Sears - 27 Oct 2004 20:33 GMT Yvan, Someone on Audifans wrote that using an _UNLIT_ propane torch (with the car outside in a well ventilated area, etc. etc.), you could find intermittent vacuum leaks by flowing the stream of propane gas over the intake hoses with the engine running. If the engine rpm raised with the torch tip near a hose or connector, there would be a good chance there was a leak in that area. I've never done that test, and of course you know that propane can burn and blow stuff up, but it's a test others have used successfully. No probs on the help. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
Yvan - 27 Oct 2004 21:54 GMT Nedavno Steve Sears pise:
| Someone on Audifans wrote that using an _UNLIT_ propane torch (with | the car outside in a well ventilated area, etc. etc.), you could find [quoted text clipped - 4 lines] | of course you know that propane can burn and blow stuff up, but it's a | test others have used successfully. No probs on the help. Thanks again for all your help.
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Wolfgang Pawlinetz - 27 Oct 2004 21:55 GMT >I've never done that test, and of course you know that propane can burn and >blow stuff up, but it's a test others have used successfully. Can't one just use startpilot? Startpilot is a spray which is useful for carburator engines if they don't want to start. Spray it into the air intake during turning of the engine. I suppose it's alcohol or ethane.
Should provide the same result as it's made for that purpose, but it could possibly be a bit safer than propane.
Don't know, however, what the english brandname is.
Regards
Wolfgang
 Signature 1999 Audi A6 Avant TDI
Steve Sears - 28 Oct 2004 14:11 GMT Wolfgang, That sounds like the "Quickstart" that my dad used to use to get the old '68 Dodge Monaco going on cold mornings - it's ether. I've also heard of using WD40. The propane method sounds good because you're not waiting for the last spot you sprayed to dry up before you move on to check a different hose. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> >I've never done that test, and of course you know that propane can burn and > >blow stuff up, but it's a test others have used successfully. [quoted text clipped - 12 lines] > > Wolfgang Yvan - 29 Oct 2004 15:07 GMT Nedavno Steve Sears pise:
| Wolfgang, | That sounds like the "Quickstart" that my dad used to use to get the | old '68 Dodge Monaco going on cold mornings - it's ether. I've also | heard of using WD40. The propane method sounds good because you're | not waiting for the last spot you sprayed to dry up before you move on | to check a different hose. It sounds dangerous to me. If I have bad spark plug wire, or exhaust is leaking, I cold burn car or myself :-)
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Yvan - 03 Nov 2004 21:59 GMT Nedavno Steve Sears pise:
| The propane method sounds good because you're | not waiting for the last spot you sprayed to dry up before you move on | to check a different hose. Does my (5 cyl, 2.3 NF normally aspirated) engine have PCV (positive crankshaft ventilation) valve? If it does, where is it? I'd like to check it.
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Steve Sears - 04 Nov 2004 14:59 GMT Yvan, No, I don't believe that it has a valve, but it should have a vent hose that collapses over time. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> Nedavno Steve Sears pise: > [quoted text clipped - 5 lines] > crankshaft ventilation) valve? If it does, where is it? I'd like to > check it. Yvan - 04 Nov 2004 15:56 GMT Nedavno Steve Sears pise:
| No, I don't believe that it has a valve, but it should have a vent | hose that collapses over time. OK, thanks. I recently replaced that hose.
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Yvan - 06 Dec 2004 17:59 GMT Update:
I disconnected ISV electrical connector, and result is that engine idles OK when warm (50 deg Celsius or more). The higher the engine temperature, the higher the RPM, but no more than ~900.
When I stop, rpm does not drop low to ~600 rpm and then up to ~900 and then to normal 750 as it does with ISV connected. It just goes down to to ~900 or less depending on engine temperature.
Am I right to assume that my problem is ISV?
How do I find out if it is exactly ISV an not some sensor somewhere that sends wrong signals to ECU? I have oscilloscope and digital multimeter so I would appreciate if anyone can give me details, or point me to some url on the net with detailed specification of voltages (or any other way to determine what is not functioning correctly).
I ordered Haynes manual from haynes.co.uk, but it has not arrived yet.
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Tony - 06 Dec 2004 19:34 GMT I do not see a thread where you described what problem you are trying to correct.
Also, What car is this?
If a T44, you might want to see numerous threads on this at Audiworld: http://forums.audiworld.com/v8/
The ISV is operated with the ISV controller (in T44s it is in drivers side under dash in Aux relay panel).
One input that it uses is a temp sender (on T44, I5 it is under the upper radiotor hose)
> Update: > [quoted text clipped - 15 lines] > > I ordered Haynes manual from haynes.co.uk, but it has not arrived yet. Yvan - 06 Dec 2004 19:48 GMT Nedavno Tony pise:
| I do not see a thread where you described what problem you are trying | to correct. I have problem that I briefly described in my previous post. When I stop the car rpm drops to some 500-600 and then sometimes stalls, and sometimes goes up to 900-1000 and then back to standard 750.
| Also, What car is this? 1989 Audi 100 2.3E (NF 5-Cyl. engine).
| If a T44, you might want to see numerous threads on this at Audiworld: | http://forums.audiworld.com/v8/ It is not V8.
| The ISV is operated with the ISV controller (in T44s it is in drivers | side under dash in Aux relay panel). | | One input that it uses is a temp sender (on T44, I5 it is under the | upper radiotor hose) I found some instructions here:
http://www.sjmautotechnik.com/trouble_shooting/injector.html#mixture
but it seems it is not for my NF 5-Cyl. engine. But I am going to test it like this anyway.
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Steve Sears - 06 Dec 2004 20:12 GMT Yvan, The temperature:rpm correlation should be about right, as the LPG will turn to a more diffuse gas with greater heating, and you are using the engine coolant to heat the LPG, right? It sounds like the ISV is indeed working, but the feedback from it being designed for a different purpose than LPG sounds like it may be causing the problem (by working properly!) - I suggest that you may have to rig in a way to disable the ISV when you are running LPG, as the engine runs properly when you're running on gasoline, correct? Thus, when the LPG turns on (engine at required temperature), then you would have to take the ground connection away from the ISV. I expect that there may be a relay doing that already - to shut off the fuel pump. BTW, the Audiworld type 44 (aka type $$) forum, which covers 100/200/5000/V8 (and, apparently 500 in South Africa and other places) - appears as: http://forums.audiworld.com/v8/ - it's not just V8's covered in there And the "Haynes" manual?.......ugggh! When you read "Assembly is the reverse of removal" you'll realize why the Bentley Manual is worth the extra $ for those who actually do work on their car. Steve Sears 1987 Audi 5kTQ - Bentley Manuals (2 volumes) referred to often 1980 Audi 5k - Bentley Manuals (2 copies of 1 volume) close at hand - Haynes/Chiltons manuals use to keep Bentley Manual pages from blowing aroung as I work outside - and as Joke Books 1962 and '64 Auto Union DKW Junior deLuxes - pre-Bentley Factory Manuals (in German and English) in use....along with Babelfish (SPAM Blocker NOTE: Remove SHOES to reply)
Yvan - 06 Dec 2004 21:22 GMT Nedavno Steve Sears pise:
| The temperature:rpm correlation should be about right, as the LPG will | turn to a more diffuse gas with greater heating, and you are using the | engine coolant to heat the LPG, right? I think that engine coolant is used only to keep vaporizer from freezing and it perhaps heets lpg spmewhat, but I think that does not make any difference.
| It sounds like the ISV is indeed working, but the feedback from it | being designed for a different purpose than LPG sounds like it may be | causing the problem (by working properly!) - I suggest that you may | have to rig in a way to disable the ISV when you are running LPG, as | the engine runs properly when you're running on gasoline, correct? No. It is the same, gasoline or lpg, I did some more testing. Perhaps a problem is not so big on gasoline as it is on lpg, but it is there.
| Thus, when the LPG turns on(engine at required temperature), then you | would have to take the ground connection away from the ISV. I expect | that there may be a relay doing that already - to shut off the fuel | pump. I can install a switch to disconnect ISV, but as I just wrote I have the same problem with gasoline too.
| BTW, the Audiworld type 44 (aka type $$) forum, which covers | 100/200/5000/V8(and, apparently 500 in South Africa and other places) | - appears as: http://forums.audiworld.com/v8/ | - it's not just V8's covered in there I will check thaere, thanks.
| And the "Haynes" manual?.......ugggh! When you read "Assembly is the | reverse of removal" you'll realize why the Bentley Manual is worth the | extra$ for those who actually do work on their car. It seems like I will have to get the Bentley Manual, I just received Haynes manual for '77 Puch Maxi that I own, and I am completely disappointed. It looks like "complete idiots guide" to disassemble and assemble moped's engine. I did that without the manual.
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Yvan - 08 Dec 2004 15:29 GMT Nedavno Steve Sears pise:
| It sounds like the ISV is indeed working, but the feedback from it And am I right to assume that there is no vacuum leak, since when I disconnect electrical connection to ISV, when I stop, rpm does not drop low to ~600 rpm and then up to ~900 and then to normal 750 as it does with ISV connected.
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Yvan - 14 Dec 2004 19:25 GMT Nedavno Steve Sears pise:
| And the "Haynes" manual?.......ugggh! When you read "Assembly is the | reverse of removal" you'll realize why the Bentley Manual is worth the | extra$ for those who actually do work on their car. You are right! Just got my Haynes. Not much to help me solve my problem. There is no information where is located ISV Control Unit for my car. I wanted to test it according to:
http://www.sjmautotechnik.com/trouble_shooting/injector.html#mixture
but when I removed driver side parcel shelf I could not find it. There were only few relay's and connectors.
Anyone knows location of ISV Control Unit on 5-cyl. 1989 Audi 100?
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Tony - 15 Dec 2004 04:14 GMT Bentley says that it should be in the aux relay panel (by drivers left knee under dash on left hand drive cars). It looks like a relay but is double the width of a normal relay. Bottom row of relays.
> but when I removed driver side parcel shelf I could not find it. There > were only few relay's and connectors. > > Anyone knows location of ISV Control Unit on 5-cyl. 1989 Audi 100? Yvan - 15 Dec 2004 16:27 GMT Nedavno Tony pise:
| Bentley says that it should be in the aux relay panel (by drivers left | knee under dash on left hand drive cars). It looks like a relay but is | double the width of a normal relay. Bottom row of relays. | > | > Anyone knows location of ISV Control Unit on 5-cyl. 1989 Audi 100? I looked there, only 4-5 wire connectors and 2-3 relays, none of them wider than normal. I will look again soon (to cold now).
Or is it different on European models? Anyone from Europe?
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Steve Sears - 16 Dec 2004 16:48 GMT Yvan, You might want to look close to the relays you have found, in my 1987 5ktq there are a set of relays accessable by a cover, but there are also some relays mounted beside them. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> Nedavno Tony pise: > [quoted text clipped - 8 lines] > > Or is it different on European models? Anyone from Europe? Yvan - 18 Dec 2004 13:39 GMT Nedavno Steve Sears pise:
| You might want to look close to the relays you have found, in my 1987 | 5ktq there are a set of relays accessable by a cover, but there are | also some relays mounted beside them. I took some pictures:
http://photos.yahoo.com/perlica
Black box that I outlined with red color is Bosch car alarm. Nothing looks like ISV Control Unit. Am I looking at right place? Look at first two photos.
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Tony - 19 Dec 2004 00:34 GMT That is where you should find it.
Like I mentioned before, that is where it should be. I remember someone commenting on the Audiworld form (T44 / V8) that some years controlled the ISV from the ECU but I am not sure if that is correct and what years it would involve. You may want to ask the question there as well.
Tony
> Nedavno Steve Sears pise: > [quoted text clipped - 9 lines] > looks like ISV Control Unit. Am I looking at right place? Look at first > two photos. Yvan - 19 Dec 2004 10:36 GMT Nedavno Tony pise:
| That is where you should find it. | [quoted text clipped - 3 lines] | and what years it would involve. You may want to ask the question | there as well. I will, thanks.
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Yvan - 26 Jan 2005 20:31 GMT Nedavno Steve Sears pise:
| You might want to look close to the relays you have found, in my 1987 | 5ktq there are a set of relays accessable by a cover, but there are | also some relays mounted beside them. I found ISV control unit. It is integrated with fuel injection control unit, and is under right side kick panel, and ISV is connected to it. I checked connection and it is OK. Ignition control unit is under left side kick panel, and idle and full throttle switches are connected to it (and the connection is OK, and switches work as they should).
Since I did not knew how to fix my idle problem proper way I decided to do the only way I knew. I cut the wire from fuel injection control unit to ISV just in front of fuel injection control unit, and then used rear fog light switch on the dash for connecting and disconnecting ISV.
Hire is how it now works: I switch ISV on, start the car, and drive for a while until engine warms up to ~50 degrees Celsius. I then hit the switch, and disconnect ISV, and engine revs nicely around 800 rpm. No stalling - hesitating then. Not the best solution, but it works.
I was wondering if I could do some damage by disconnecting ISV while engine is running?
Am I right to assume that there is no vacuum leak if engine does not stall with ISV disconnected?
And since idle switch works, and its connection to ignition control unit is OK, as is ISV - fuel injection control unit connection, perhaps ISV is my problem. On the other hand I cleaned ISV with carburetor cleaner (I should use throttle body cleaner as I learned later), and checked it with 9V battery, it seemed OK to me. And I did put another ISV (but not from NF engine, it was slightly different), and my problem did not go away:-(
Anyway I temporarily solved my stalling/idle problem.
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Randolph - 06 Dec 2004 21:11 GMT > I have problem that I briefly described in my previous post. When I > stop the car rpm drops to some 500-600 and then sometimes stalls, and [quoted text clipped - 3 lines] > > 1989 Audi 100 2.3E (NF 5-Cyl. engine). I have an '87 VW Golf GTi with CIS-e (= KE-Jetronic) fuel injection. I too had a problem with idle speed earlier this year. I first suspected the ISV and replaced it (the replacement cost me $4, so replacing it was cheap troubleshooting). No change. I then found out the the idle position switch (the switch that closes when you release the gas pedal) was broken. The fuel injection system would never know to get into idle mode, and thus the idle speed was off. A new switch (they are sold only in a set with the wide open throttle switch for my car) was over US$100 from the dealer so I went to a local junkyard. What I found was that a large number of both Audis and VWs at the junkyard had broken idle position switches, so it seems to be a common problem for VAG vehicles of that vintage. I eventually found a working one from a slightly newer car with Digifant, not CIS-e. The switch is the same for the two, but the wiring is different. The switches are located on the throttle body, on mine there is one switch in plain view on top, which is the WOT, or wide open throttle switch, and another underneath the throttle body. This is the idle switch. Your car may be different.
I don't know what type of fuel injection you have on your car, but I believe you said you do not have an oxygen sensor. That would be consistent with CIS (= K-jetronic), and I believe (but am not sure) that CIS uses the same switches as CIS-e. The simplest test of the switch is to open the hood and move the throttle by hand between closed and barely open. If the switch is working, you should hear the clicks at is turns on and off. The broken switches I have seen have had the plunger fall out, so that the switch would not operate at all. Another test is to disconnect the switch and short the two wires that goes to it. If shorting the wires make the idle go back to normal, you can be pretty sure there is a problem with the switch.
Yvan - 06 Dec 2004 21:31 GMT Nedavno Randolph pise:
| > | Also, What car is this? | > [quoted text clipped - 4 lines] | the ISV and replaced it (the replacement cost me $4, so replacing it | was cheap troubleshooting). ISV for my car is $220 (BOSCH 0 280 140 512) Audi part 034 133 455B is probably more $$.
| No change. I then found out the the idle | position switch (the switch that closes when you release the gas | pedal) was broken. One on my car works OK. I checked.
| I don't know what type of fuel injection you have on your car, but I | believe you said you do not have an oxygen sensor. I have O2 sensor.
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Tony - 06 Dec 2004 22:08 GMT > Nedavno Tony pise: > [quoted text clipped - 10 lines] > > It is not V8. The forum link that I gave is for all Type 44s ('82 to '91) and most of the discussion is for the five cylinder engines.
> | The ISV is operated with the ISV controller (in T44s it is in drivers > | side under dash in Aux relay panel). [quoted text clipped - 5 lines] > > http://www.sjmautotechnik.com/trouble_shooting/injector.html#mixture Very good source for information. SMJ site is nearly the 'bible' for T44 series.
> but it seems it is not for my NF 5-Cyl. engine. But I am going to test > it like this anyway. That would be a good start.
Good luck.
Tony '91 100q 5spd ISV BTDT
Steve Sears - 06 Dec 2004 19:56 GMT Tony, Yvan has a Type $$, but he's running an LPG convertion on his car. You'd have to look at the a.a.a archives to see the troubleshooting that went on a couple of months ago. Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)
> I do not see a thread where you described what problem you are trying to correct. > [quoted text clipped - 28 lines] > > > > I ordered Haynes manual from haynes.co.uk, but it has not arrived yet. Tony - 06 Dec 2004 22:10 GMT Oh, that's right and the thought is that on LPG the ISV might be functioning just opposite from gas due to the location of the LPG infection.
Tony
> Tony, > Yvan has a Type $$, but he's running an LPG convertion on his car. You'd > have to look at the a.a.a archives to see the troubleshooting that went on a > couple of months ago.
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