After much effort and anguish, my car is once again in full health. I had a stalling problem which seems to be quite common in these cars. It would start and run for a time then the run badly and die. It would sometimes refire, sometimes not. It deteriorated to the point that it would only run for 10 sec before stalling. I went over the usual suspects (ref/speed sensors, fuel preesure, DME relay, TPS, Airflow sensor) etc and everything checked out.

The clue that provided the solution was when I was checking spark. I was using a timing light hooked to each of the plug wires in turn. Easier and safer than fussing with unplugged plug leads. Just for laughs I shined it in the inspection hole above the distributor cap. When the car started to run badly, the timing retarded a few degrees (a tooth or two on the cam pulley) and would wander around. I suspected a bad knock sensor/KLR system since that is what is supposed to happen in a knock situation. I bought a used KLR which turned out to be bad (no spark at all).

Then I read one of Danno's posts that said that the DME generates a retarded spark in these situations. On hunch, I bought a rebuilt DME and like magic the car was fixed. Loren at Systems Consulting tested my DME and verified a problem with the timing section of the unit.

The Rennlist has been a life saver to me. I could not have fixed this complex car without the collective knowledge of the group.

 

Would this make a car stall at idle, but still run fine?? This is my problem now. Wants to stall when first started up if I don't keep reving the motor, then once it is warmed up, it wil hold idle most of them time and makes full boost, but vac gauge is reading about 12 at idle when normally 18.

Check most things I can think of, even new TPS and all boost/vac lines.

 

Just a hunch, but when did you last change the fuel filter? I had a similar problem Todd, and that and a new DME relay did the trick. Cheap and easy, boost is back and the car runs like a champ. Just a (cheap) thought.

 

Fuel filter is a few moths old and have new DME relay only 1 month old. So I am stumped

 

toddk911 ... had the same problem. Check the intake manifold and torque down the bolts. My bolts where loose and the gasket was broken. The air leak would seal up once the engine would heat up.

Jaak Lepson

 

Todd's problem may be the temp sensor in the head. It changes resistance with temperature. When the engine is cold the DME senses this and richens the mixture. There are resistance specs for different ends of the temp spectrum. I took mine out of the car and set it up in a pan of water on the stove. I heated the water and watch the resistance change.

 

I have the same problem as Todd. It is getting worse every day. The amount of time I have to hold the throttle up after cold starting is only 20 seconds or so. Could this be enough time for heat to expand the manifold and seal a leak. Car starts and idles fine the whole day and the process repeats the next morning.