I have a 95 Z34 Monte Carlo. It idles at about 2,000rmps in park and neutral. It has had the head and intake gaskets replaced. The check engine light comes on and stays on for a while then shuts off and comes back on again. any ideas as to what would cause these issues?

 

What engine do you have? dose it idle high at a constent rate or does the rpm needlemove around, like it gose form 900 to 2,000 then 1,500, and keep bouncing around like that untill you put it in Drive?

 

Does your Monte have the 3.4X overhead cam engine? Did the high idle issue start after the head and intake gaskets were replaced? A vacuum leak could cause a high idle like you describe.

 

It has 3.4l overhead cam. the needle jumps around. It does almost exactly waht you just said. This problem atarted after the intake and head gaskets were replaced. How do I find the problem if it is a vacum leak?

 

Did shop that changed your head and intake gasket change your spark plugs?

 

Im not sure if the plugs were replaced or not, but the wires look newer. We just bought the car. It also has a hard time starting only when its cold. At 70mph the tack reads around 3000. Is that normal?

 

i would have to agree that its most likely a vacuum leak even tho the gaskets have jsut been replaced.