I'm not sure if I should worry about it or not...?

Question

I have a 1996 2.4L Pontiac Sunfire GT. It does this weird thing when I start it for the first time in the morning where it doesn't idle right. It will rev and then slow down, in quick succession, over and over again. Sometimes if I turn it off and start it again, and it will stop. Other times I have to start it and turn it off several times. I'm not sure if it's just because it's cold or what, because it won't do it again the rest of the day. Help!

Answer 1

may have a faulty temp sending unit that is reporting to the computer tat the engine is warmer thain it really is

a scan tool that reads data can tell you if that is the problem

Answer 2

A "rolling idle" indicates a lean condition with not enough fuel being injected into the cylinders, or an unmetered air leak from a vacuum leak or EGR valve leak etc. You should also have the Engine Coolant Temperature ECT sensor checked because it tells the computer to inject more fuel on a cold start. Your engine may be carboned up including the backs of your valves which creates a lean condition by soaking the fuel up. Use BG44k or Chevron Techron Concentrate fuel tank applications to remove carbon. Buy "Top Tier" gasolines.

http://www.toptiergas.com/
http://www.chevron.com/products/prodserv/fuels/additives/concentrate_plus.shtml
http://www.bgprod.com/home.html



http://www.autozone.com/az/cds/en_us/0900823d/80/04/f5/ac/0900823d8004f5ac/repairInfoPages.htm

Answer 3

It could be a number of things.

More than likely it is a sensor on the engine.

If I had to guess I would say the TPS sensore is bad.

TPS= throttle position sensor.

Best bet is to get a obd2 computer scan done and check for trouble codes.

Then you will know for sure.

Answer 4

Check to make sure your air intake is on tightly. A vacuum leak there would do it.