So the shop had the car for three days and never found a problem.

I have noticed the car will give trouble in another way. You drive the car until it is warmed up good and park it for 15 minutes. It will bog while accelerating the first few times just like with a cold engine. It usually needs a small hill to give it trouble though. The mechanic's shop is on a flat highway. They have to accelerate hard to get out into busy traffic so never could replicate the same conditions I have. Any ideas out there? thanks,

 

So was the ruined IACV replaced?

Could you make and post a video showing the instrument cluster when problem occurs?

 

The idle air control valve assembly is new. My wife tried to drive it this morning. It actually stalled out on her while driving around in a parking lot (cold engine). She was in the store a few minutes and it bogged down going down a hill at the store. I'll experiment with it this afternoon and try a few different things to learn more. I don't have any video equipment though. I'll try and report what the instruments do during the acceleration trouble. Still no check engine light.

 

Cell phone would do.

 

I know this is out there.....I'm almost to the point of thinking the egr is hanging open.

Full throttle, everything is fine. When cold and under load and light throttle, engine wants to die out......ever opened the egr valve on an engine at idle, what happens?

At the begining of this I asked about the cold or hot issue as I was thinking the port in the intake could be clogged but the more I read this I'm thinking the valve is not closing off all the way.....thus when cold and under load it won't go.

Cost, at most an egr gasket and some carb cleaner to prove me wrong.

 

Well, more testing today. The bogging starts and the tach gently falls down from 2,000 to 1,000 then with a jolt the engine kicks back in like someone is stamping on the gas. Meanwhile, the gas pedal is held steady the whole time. If you press hard enough it will downshift and sprint away. After this burst of power sometimes it will sputter and stall.

Now check this out. The car runs fine after the first few stop signs (not really warmed up fully). If you park the car for more than ten minutes it will do the same thing (engine sputtering). If you idle the engine for a minute or two in park it will drive fine with no problem. Could it be the fuel pump starting to die? If you try and load the engine with anything more than idling it will stall and sputter. After just a little idling it will perform just fine. Tomorrow I'll try from dead cold in the morning.

The egr passage and valve have been cleaned when I did the throttle body cleaning. The egr passage was sooty but not really clogged at all. The valve itself is not vacuum but electronic actuated so a little tough to test. The car will stall hot and cold now. I guess I need to change the name of this thread?

 

I would check ignition timing and ECT sensor. Your car should be idling higher when cold than when warm.

 

Did you do a compression test? I messed around for a year with a bad idle issue and nothing worked. I finally did a compression test and found I had only sixty pounds on the middle front cylinder. Before that discovery, I did everything bleed the cooling system, new wires, egr port valve adjustment etc and nothing worked. Before you waste time money and energy do this simple test with the motor running at idle and warmed up pull the dipstick and watch if puffs smoke like an old steam locomotive you have a blowby issue mostly likely related to cracked ring in the middle cylinder. The problem starts out as a rough idle that slowly gets worse, then you'll get intermittent codes like 300...306 (misfires) then the car will start dieing at ilde, finally you will start using lots of oil and the oil will be black as soot after a 1/2 of use.

Engines are dirt cheap for these, I paid only $200 for one with 134k and it runs great conversely trannies are very expensive at least $1000 from a junk yard and $1500 for a rebuilt from an indy shop. It's super easy to change the trans fluid so do it often.

I messed up mating the tranny to engine by bolting the torque converter to the flex plate first so I had to redo the tranny which is about 1/3 the work now I am done and it's great.