Hi my names owen and i have a 91 honda civic si hatchback with a obd1 d16z6 swap. i had just swapped intake manifold and replaced the IM gasket. i started it up and it had a steady idle at around 2k rpms and no CEL and ive been driving it like that. now when i started it it goes to 2500 rpms and drops to 1000 and goes back up to 2k and stays up there and somtimes the idle goes up and down and its very annoying. Any ideas what this might be..? thanks

 

Check the FITV on the manifold you put on the car. Chances are it needs to be cleaned and adjusted.

-Amp