1994 Chevy Cavalier

What codes are showing now?



Are you in an area that the temperture reaches freezing?

THe pcm had been a problem due to the location on these. Water would enter it and crack the case.

[quote="jkohl"]1994 Chevy Cavalier 4 cyl Front Wheel Drive Automatic

i live in the valley of oregon so doesnt get to cold here the local parts store scanner said low map pressure?

HAve you checked for an intake leak? Using carb cleaner spray around the intake gasket area and see if the idle changes.

HAs there been any work done to this just prior to this problem? In particular has the egr been removed at all?

no worl was done prior to this it just started doing it yesterday it was weird thinking may iac sensor tryed to find a book on it but the local store has none in stock so i could test the map tps sensors for ohms to see if they are bad

TPS voltage is .6V t0 4.80 V. I don't know what code number you have so I assume it is this:

If this is the right code and you can't read this, send me an email. Pukenstein@aol.com and I'll send it.

The two things I would focus on at this point...actually 3.

1-Be sure the wires and connections are good at the iac, map and pcm. Be sure the harnesses have not been damaged through heat or oil and no corrosion exists.

2-be sure there are no vauum leaks. At the manifold and all rubber goods. Look for any dry rotted, collapsed or opened up lines.

3- Clean the throttle bore with a good cleaner. May need to pick up a bottle brush to aid in this.
https://www.2carpros.com/how_to/how_to_tune_up.htm

In an email, the member found the intake manifold leaking. The unmetered air was the vacuum leak.