Pontiac Repair: 91 Grnd Am 2.5 Engine 4Cylinder, engine sensors, nature of the beast

Question
After stopping the idle drops down two different times in gear causing the car to viberate a little,like it's not
ideling fast enough.

Answer
Hi William:

That engine ALWAYS had a strange or erratic idle. It's pretty much the nature of the beast. But there are a few things that it could be if it's worse than usual. It could have a bad idle control motor. Low fuel pressure or high fuel pressure. has an service engine light come on? if so that would be a place to look A scan tool would be of HUGE help you can lood at the engine sensors and look athe the desired engine idle and actual idle speed. that engine the desired and actaul on that engine would varry 30-50 rpms and that would be considered normal on that engine. anything more that that it would be excessive. good luck :}