I would also consider checking that the coolant temp sensor is working correctly, this is not the gauge sender bit a sensor that tells the ecu the engine temp, if faulty the ecu may not be going rich for cold run conditions, often a scan will show up this fault.

Answered by mhpautos (expert)
26,910 answers provided

Thanks mhpautos for the reply, I will try replacing that part.
GMuser

Response from GMdriver
1 question asked

Dear mhpautos,

I replace the coolant temperature sensor. Unfortunatley, that did not solve the problem.

Me and a friend are working on this problem. We also replaced the IAT and the MAP sensors and checked for vacuum leaks. None of these fixes helped. So, let me describe the problem again. The car starts okay and when the engine is cold it idles rough. This is while it sits in the driveway. When I press on the gas, the engine does not rev up. It hesitates for about 5 seconds then it revs up. If I'm driving down the road with a cold engine, this is a problem. When I slow down and then speed up, the car behaves this way.

So, can you make other suggestions on what may be wrong with the car?
It's a 1993 2.2 liter (VIN 4) "L" carline.

Thanks,
GDdriver

Response from GMdriver
1 question asked