I remember someone else had this problem before and posted here and now I have that too. I have a 1989 V6 firebird and i was sitting still and the engine revs from 500 -1500 rpm randomly. What do I do to fix it?

I also have a problem with car starting. If it sits for a while, my voltage drops from 14 to about 11 1/4 volts (I measures with a digital multi meter). Sometimes the car takes a few times to start in the morning and after work. I am thinking it is my old battery. What could it be?

 

About the car reving by itself, you probably blew a head gasket. check for any leaks. later

 

does it stop after it warms up a little? the revving i mean.

 

When an engine starts "hunting" for its desired idle RPM, the IAC (Idle Air Control) valve (motor or soleniod are other terms) is more than likely the culprit.

A new IAC valve from local parts store is usually around $25-45. Fairly simple to install as well. Most of the time a little paper comes with the IAC valve which explains how to properly set it just before installation.

Another thing you might want to check is your vacuum lines/hoses which run throughout your engine compartment and into your dash (heater and a/c controls). A vacuum leak can also cause idle problems.

 

Better tell it to stop it, or it'll go blind Sounds like a vaccum leak..........

 

My Camaro used to do the same thing. I found that most of the vacume lines had dry rotted and were leaking mainly the big one to the brake booster. Cheap fix