Hey everyone,

I got a 95' Monte Carlo with the 3.4 DOHC, and it runs fine except this weird idle problem that it has. When you start the car it might idle "ok", but most of the time the idle jumps to around 1500 RPM, and sits there for a few minutes, and then returns to about 800 RPM'* for a few minutes. It will then go back to a high idle for a few minutes, and then again return to a normal idle.

The car will do this regardless of whether you are just sitting in park or driving it. Of course when you are driving it the RPM jumps are a little less, but are noticeable. I do have a check engine light, however, since it is a 95' with the transitional OBD system in it I can't readily read the codes.

Anyone have any suggestions to what the cause or remedy may be?

Thanks in advance,
Dustin

Have you by chance looked around for a vac leak? or cleaned the IAC

Hey,

Thanks for the reply!

Yes, I have cleaned the IAC valve, and didn't notice any changes. I understand that this doesn't mean that it'* not bad though, but I didn't notice any changes.

As for a vacuum leak I have checked the different lines, and if I unplug a vacuum line with the engine running there is a difference in the RPM changes, so I'm assuming that the intake gaskets are good since there was a change in RPM'*.

Also, I did notice that the engine seems to be running a little rich as you can smell it in the exhaust. Not too bad, but slightly noticeable. So if there was an intake gasket leak wouldn't the extra air lean the engine out?

Thanks,
Dustin