Whenever my 1994 Civic St coupe has been sitting for more than 3-4 hours (estimate), like in the morning or at night, the engine will rev a little up and down all my itself without my foot on the gas pedal...this just started happening and am wondering what the heck is going on...I don't want to take it to a garage b/c this car has absolutely snake bitten me and turned into the ultimate money pit....thanks for the answers.

Adrian

 

how high does it rev to? if its just a few hundred rpms, clean your iacv, or it could be a vacuum leak.

 

also check your TPS.

 

https://honda-tech.com/zerothread?id=529107

 

throttle position sensor, air leak or a vacuum leak. start checkin.