when i start up the car, somtimes the rpm meter goes up and down and up and down and up. it only happens somtimes... any ideas why this happens?

 

Check you IACV, it might be dirty, or check for any vacuum leaks around the IM. Check that and let me know wats up

 

This is what my friend's 92 accord is doing sometimes when he start it in the morning. What is this IACV and where to check for vacuums leak?

 

The IACV is the device that is located behind the intake manifold with sensors plugged into it, its usually held on by 2 screws. Unscrew it and spray brake cleaner into the side with the metal filter then drain it out. For vacuum leaks check all the hoses that connects to the IM

 

thanx, i will try that and update.

 

Is it doing it only when cold? Likely it is the FITV.