the idle speed goes up and down at idle somtimes. what could this be? its a DX 1.5 L SOHC civic HB 1989? my friends prelude does the same thing then stops after a while . what could this b? is it expensive to fix?

mike

 

check your vacuum lines

 

How much up and down does it go?

 

sounds like a vaccum problem

 

I have had that problem before. It is a vaccuum thing. One of your lines may have a hole in it. That will mess up the idle. I have a 89 DX sedan. It isnt too bad to fix. It tends to cost more for the mechanic to find the problem rather than to fix the problem.

 

MY CAR DID THE SAME THING.. I TOOK IT TO THE SHOP AND THEY CLEANED SOMETHING OUT BUT I FORGOT WHAT IT WAS CALLED. IT IS LOCATED BEHIND THE INTAKE MANIFOLD NEAR THE THROTTLE.. IDLE CONTROL VALVE? NOT SURE, ILL FIND OUT..

 

Check your EACV. (I believe 1989 is F/I right?) Its located behind the F/I near the firewall. Take it, and the hoses off and check to see if the mesh screen is clogged up with carbon and ****. If so, take some carb cleaner and some small rags and q-tips and clean it up. You can even spray a liberal amount into the EACV to get behind the mesh....use compressed air to blow the carb cleaner out before re-connecting. Re-connect and try again. If its still acting shitty, well, hey, at least you cleaned your EACV. The vacume problem sounds legit also....


[Modified by SoulflyCRXsi, 3:08 PM 3/20/2002]

 

well i hear u can spray some fluid on the vacuum lines and if it leaks the idle will rev up or somethin.. i forget what fluid it was?? starter fluid or something?? any ideas.

thanks
mike

 

In your case, you have a fast idel control valve, located under the TB. I Think with the 89-91, they have a EACV. (Electronic air control valve) which I previously explained how to clean. There is no need to take a car to the shop to have the EACV or FICV cleaned...its easy stuff.

 

Carb cleaner works well for this. Spray it on all connections and pipes your idle will jump up quite a bit if there is a leak where you sprayed it. Then Duct tape... JK also duct tape your motor mounts adds strenth.. JK