I have a 98 Z24 and when it is really cold out, the following sometimes occur (especially after it has been sitting outside overnight):
The car starts up quickly, then the rpms bounce back and forth from 1000rpm to 2500rpm for about 10 seconds (kind of like it is reving) by itself. After this, the rpms goes to about 3000rpm and comes down slowly to 1000rpm , then the car acts normally. I am not giving any gas.
I do notice the exhaust smells quite different when it is studdering vs when it goes back to normal. When it is studdering, the exhaust smells like the smell when starting a snowblower. It is quite strong.
Anyone have any ideas?
Well the first thing I would look at is for the idle air control valve sticking. I have seen it happen many times, and cold weather only makes it worse.
- 2004 Cavalier - 124k, owned since new
Happened to me when my coolant temp sensor was broken, the car doesn't realize the engine is so cold and messes up the timing/fuel for a little bit.
How expensive would it be to replace the coolant temp sensor?
^^^^
They are only about $15, but I seriously doubt thats it
- 2004 Cavalier - 124k, owned since new
when it acts up, tap on the IAC with the handle of a screwdriver, sumtimes this will jog it loose, and willhelp u diagnose it
