There's about 7K miles on the car, due to an accident, the engine was rebuilt at around 1K miles. Up to this point, it's had all its scheduled maintenance.

 

Shamu, does this problem occur when the A/C is on only or does it do this even when the A/C is off? Mine was doing this the first summer I had it only when the A/C was being used. It seemed the additional drag on the engine at idle was something the ECU could not compensate for quickly enough and it would almost stallbut never quite died. After about 2-3 weeks of this, the ECU seemed to learn and immediately responded when the A/C was on and the revs dropped to idle. It has never done it since. I have used the A/C a few times lately and no problems. I'm hoping that before you actually take it in and have it "fixed" that it will resolve itself and you won't have to have it fixed.
My Corvette used to do this too but that thing never "learned" and the dealer resolved the problem by using a "carb" cleaner and completely cleaning out the throttle body plate and throat. This cured that problem.
My Viper used to do it too but that was because of a bad tank of gas (too low octane). A bottle of octane boost got me through that tank. I changed brands and it never happened again.

 

How bout a valve adjustment?

 

This is going to sound real strange but bear with me. When I was running a 1996cc type 4 motor in my 917 replica I got the same problem. It ended up being the ultralightweight flywheel.

The reaction time of the ECU of the Fuel injection just would not compensate for the higher speed rpm shifts and would get confused. Its just a though but it used to run fine at high rpms and then if I smashed the clutch and dropped the revs while still moving forward it would simply die as the mass on the flywheel just would not sustain idle at least in the ECU's mind. This is 30 year old technology though so the newer stuff more then likly could handle this but it's a guess.

 

[QUOTE]Originally posted by StormBringer
[B]This is going to sound real strange but bear with me. When I was running a 1996cc type 4 motor in my 917 replica I got the same problem. It ended up being the ultralightweight flywheel.

 

Good luck with all the big changes you have to your car it must be a adventure. Also the lightened internals will simply just exsaperate (sp) this problem. Real quick test is to run the car quite hard after a nice warm up. Do a real quick rum to 3rd gear all the way to 9K, then slamm the clutch in and hit the breaks, do this a few times. This is the only way I was ever able to replicate the problem. Good luck keep us posted.

 

Hi Shamu,

I had a similar stalling problem last weekend.

On Saturday morning my alarm company rang me to tell me a battery disconnect alarm had been triggered. What had actually happened was that my battery had gone flat. Probably due to an alarm system that uses radio to talk to the monitors. But I digress.

I charged the battery and then took the car out. Every time I dropped to idle (traffic lights, intersections etc) it would drop revs and stall. Just out of interest it was a very cold day.

It hasn't played up since. I guess it was the ECU relearning by trial and error.

BTW, I changed my spark plugs for Iridiums a couple of weeks ago.

 

At first I thought it was the battery leaking or losing its charge, but a battery shop tested it and it passed with flying colors...

Update on thumping the MAP -- this seems to work, but it's not a 100% fix for me...hmmm...

 

I've had this problem since the day I got the car and it now has 15K miles on it. I have checked/tightened the plugs, taken off/cleaned/re-installed the map sensor, tried fuel injection cleaner, tightened the throttle cable (just cause there was too much slack, not to increase RPMs - that's bad), but nothing has helped. The problem is inconsistent and not easy to reproduce at the dealership so I've basically gotten over it since it has never actually stalled. :-(

 

We have all experienced the dreaded "morning shudder". Few understand it and you will see post after post about it. I agree a MAP sensor tap might work but why? More likely the issue is with STFT:

http://www.amazon.com/exec/obidos/ASIN/097...0145865-3338533

This book and 100 bucks in software can save a lot of people a lot of money.