BadComrade

New variation on an old problem?:

Last week I start up my 85 CGT, start driving, and 30 seconds later the engine kinda hesitates, then dies. Obviously I re-start it, and same thing happens. So I pull over, try to start it, and have a hard time getting it started. Finally starts, but after a couple of seconds the engine dies in the *exact* same way it does when you turn off the ignition. Tach falls straight to 0 as if it was unplugged, etc etc etc. Same thing happens the next few times I start it. Having the hood open and no tools but my own hands, I disconnect the connector on the ISV, and it starts / runs fine. If only someone easily impressed had been with me...

SOOO a few days later, I decide to reconnect the ISV while the engine is running to see if the car will stall again. "No dice". The car runs normal with it re-connected again until a few days later when it stalls again in the same way as before. So, I disconnect the ISV *again* with plans to clean it out in the near future. Drive the car for a few more days with it disconnected, and it runs normal until -TODAY-. While (of course) sitting in the middle lane of Lake Shore Drive at the height of travel on Memorial Day at a red light here in Chicago, the engine just dies without warning in the same way (as if I turned the key to off). Won't start (in the same was as the beginning). Finally get it started, and it dies (again, same way). I eventually FIX the problem by RE-CONECTING the ISV with the key in the "on" position and disconnecting it a few seconds later, and the car gets me all the way back home with no more stalling.

My guess is that maybe the ISV was in a position to cause the car to stall when the problem originally happened, and maybe the vaccum running through it got it back to that "bad" position today while it was disconnected and my temporarily reconnecting it jarred it to a position that would let the car run well with it disconnected again? (haha yeah right) I've read that disconnecting the ISV should cause the engine to act weird, and mine didn't. When I disconect it the only thing that changes is that the idle goes up maybe a few hundred RPM...

I've also read about a micro-switch that apparently lives under the throttle body that cuts gas to the engine above 1800 RPM when you let off the gas? Maybe this switch is faulty in some way where it's randomly cutting gas to the engine and my disconnecting the ISV had some sort of weird electrical effect on this switch causing it to work right again?

Oh, and by the way... as far as Vaccum issues... the breather hose that always collapses on these cars is indeed collapsed (but bellows up when the engine is reved) and I *think* I noticed a bit of oil on one or two of the fuel lines near the injectors (possible O-ring leaks i.e. vac leaks) but I don't see how a vac leak would only cause this intermitent stalling problem.

Any thoughts?? Anyone have this happen?? Thanks in advance!

Chris Hall
bad_comrade AT megsinet dot net

austinado16

You probably have a broken connector at the distributor to the Hall Effect Sensor inside the distributor. It's very common and easily fixed by JB Weld Epoxying it back in place and securing it there with a zip-tie. Note that your main symptom is dead ignition, including a dead tach. A failing ISV would just give you poor idling, it wouldn't kill the engine.

The reason why disco-ing the ISV made a difference is because you're pulling on the wiring and moving the connectors.

Sounds like you need to replace that collapsed breather hose, replace the valve cover gasket, and then turn you attention to maybe a tune up....ie, plugs, cap, rotor, maybe plug wires, and an air filter..... if you haven't done them in a while.

BadComrade

I just looked at the plug on the back side of the distributor, and guess what? It's mount is loose and there's electrical tape and a loose zip-tie around the wiring. I'm guessing one of the previous owners had the problem I'm now having, and used your prescribed fix. Must be time for a new zip-tie!!! I don't think I "moved" this wiring when unplugging the ISV's connector, but I probably did "check for loose spark plug wires" etc etc in my frustration on the side of the road haha.

I don't have time to mess with it right now, but as soon as I try the fix, I'll let you know if it worked (I'm guessing it will since it seems to have worked with the old zip-tie)

I'm just glad it's not the ignition control module, etc.

Any idea of where to get a replacement plug? Believe it or not, it's pretty hard to find Audis in Chicago area yards...

austinado16

A day or so ago for $90. I think I found it when looking for VW parts. It was the complete unit.

My fix isn't electrical tape and a zip tie. My fix is to epoxy that connector plug back in place in the distributor. It's a permanent fix.

I suggest using the zip tie because that holds the plug in place while the JB Weld cures. You can speed up the repair process using a hair dryer to heat up the JB Weld after you apply it. It'll dry in about 10 minutes once hot.

Pretty common failure on the 5cyl cars though.

BadComrade

Ok, so I finally had a chance to play around with the plug and connector for the hall generator. I ran the engine, wiggled the HELL out of the plug and female connector that goes to the wires that go inside the distributor to the hall generator... *No* stalling at all. I had to unplug the connector to get the engine to kill instantly as it has done to me 3 times now on the road.

SOOOOO, I'm wondering if a -failing- Hall Generator will occasionally have the same effect as disconnecting the plug leaving the sender? (By the way, the electrical tape / zip tie I spotted seem to only have been placed there to protect the crumbling rubber boot that covers the wires coming out of the male connector)

Like I said, the only way I have ever "fixed" this weird stalling problem as my car sat dead on the road was to unplug the stupid ISV connector. 2 times the car died with it connected (and disconnecting it got the car going again), and one time it died with the plug disconnected (and reconnecting it for a few seconds then disconnecting it got the car going again...) I know it makes no sense but that's what worked, and I don't think I tugged on the wires to the Hall since they're not really near the ISV wires and I just shook them and nothing happened...

Any other ideas? Maybe something in the ECU is acting up?

Looking forward to some more good ideas...

austinado16

You're just going to have to go over all the wiring that controls fuel injection and ignition. Since you lost coil signal, that's a big hint.

Make sure all the engine and battery ground connections are clean and tight. This doesn't mean looking at them and saying they look fine to you. This means remove them all, clean the connector and clean the surface they attach to. Then reinstall them, battery also. I don't say this to be a jerk, but you'd be surprised how many times this type of advice is given (by myself and others) and the person with the problem doesn't actually do anything other than lift the hood, look around and say, "looks fine. Still doesn't run right."

I'm not saying that's you, I'm just saying be thorough. You'll find the problem.

After cleaning the grounds, start it up and start tugging on all the ignition and fuel injection related wiring, just as you did (good job) with the hall effect wiring. By the way, make sure you epoxy that connector back in place because it could still be the problem and engine vibration contributes to it failing.

BadComrade

Yeah, on my old `83 I once removed the little ground wire on the pass side of the head (or somewhere) then couldn't understand why my idle disappeared... car would drive, just not hold an idle... haha. Then I reconnected that ground and it worked fine.

I guess I'll try and trace down all the grounds I can (any idea where they *are*? maybe the ones I mentioned above are the ones?) and do what you said. I just have a feeling that the little sensor in the hall generator might be going bad... who knows, maybe it's the coil, a bad ground wire in the loop of wiring within the ISV / hall connectors, etc... or maybe I should just take it to my mechanic and let him figure it out haha. The female connector on the side of the distributor is still connected (I've read reports of them breaking off and dangling... mine only moves about 1/16th of an inch away from the distr. when you wiggle it) and the wires I could see inside didn't look like they had been shredded or anything, etc so I'd hate to JB weld it on in case I ever had to remove it...

Thanks for all the help!

BadComrade

Turns out it was the Ignition Control Module. The original Telefunken ICM was dying, causing the ignition to cut out whenever it felt like it. Could go two days with it not happening, then it would happen again. I seemed to get good results when disconnecting the ISV, but I started to figure that really what I was doing was passing time. Maybe the ICM was over heating and the time I spent under the hood was letting it cool down? No idea. Funny thing is, I won a $10 Lucas module on ebay that was "new", and I installed it. Car ran fine for a bit (as it would have with the bad module) and then different problems appeared. The tach needle started dancing all over the place with the engine idle steady, and eventually the enging idle changed and held at different idles and eventually i could floor the gas pedal and get no response from the engine. SO, I yanked the ICM out of my `83 Coupe and tried that. Car's been fine ever since.

Thanks again for everyone's help...