cyang08

i have a 1994 honda civic Dx. the motor is stock except for intake and catback. when i start my car from a cold start, the idle goes up and down and i can hear it in my engine like its pulsating. then i start driving and when i come to a stop same thing happens. when the car warms up then the pulsating goes away. does anyone have the same problem with their civic? and can anyone help?

90CvcDX

i have this same problem and tried to look for a solution but there are just so many factors i was told, one being that the engine is cold/ outside weather is cold, or sensors... i would like to know a fix to this issue too because when i am going really fast and come to a light my engine wll pulse like his does... the thing with mine is when i hold down the brake really hard it stops pulsating, does yours do that too?

RedlineBoyzCRX

The problem I have found is that it is with the IACV Idle Air Control Valve. Try taking your IACV off of your intake manifold, take it completly apart and clean the hell out of it, shoot air thru it, thw works. Let it completly dry out and put it back together, reset your ECU. The weather does affect this, but also let your car sit in the driveay when u start it and rev it up and down a little and hold it at about 3000 RPM's. That helps too. But the main problem is that the IACV gets dirty, that is what regualtes your idle. I have fixed 5 or 6 different cars just by doing that. My friends 2002 Toyota Celcia had the same problem. Cleaned it blew it out, let it dry and it fixed it. If that doesnt work get a new IACV.