I have a 1994 Honda Civic Ex and its giving me problems. I already took it to 4 mechanics and no one seems to know whats wrong. I was wondering if someone could help me find the problem. The car revs up and down when it gets warm on idle. It does it when you step on the accelarator. It bounces up and down for about 10 seconds and then goes back to normal. I've notice that this happens when the fan turns on. This problem makes it hard to drive because it stalls when it does this. Can anyone help me?


Modified by aguilasrafa10 at 7:31 PM 1/19/2006


Modified by aguilasrafa10 at 7:32 PM 1/19/2006

 

tps?

 

^^^ yeah i would start at the tps first then maybe the IAC

 

I had a vacuum leak and that happened too. Check that.

 

fitv (fast idle therm valve) maybe?

 

definately the TPS or a vacuum leak to the intake manifold

 

i changed the tps already and it still does the same thing. once the engine gets warm it starts doing it. it does it for about 10 seconds and then it stops.

 

Changed the tps? How did you manage that?

 

the tps is attached to the throttle body. had to change the whole throttle body but it continued to do the same thing. you have any idea of what it might be?

 

I thought you meant, actually changing just the tps. Hmm...try checking the pcv?

 

is your cel on?

 

what do you mean?

 

cel=check engine light

 

no. i dont know if its a sensor or a vacuum leak.


Modified by aguilasrafa10 at 9:01 PM 1/19/2006

 

It sounds like a vacuum leak, try listening for a hissing sound while the engine is running.

 

definitely a vacuum leak.. or you have a bad idle air control valve.

 

Did you try adjusting your idle speed. Honda's have idle problems in cold weather when an after market intake is added. And if you had a vacume leak your RPM's would drop at 4k when you speed up.