i gotta 1990 civic ef that when im idling the engine revs up and down sounds like breathing problems but only when im idle.. and i have no clue what it could be i have never dealt with this problem before so if u have some helpful information please let me know.

 

vacuum leak?

 

answer these questions first...

-what type of motor?
-what is your idle at start up, and what does it fluctuate between? (i.e. 500-1000rpm)
-have you recently added/flushed coolant from the radiator?
-have you removed/replaced any sensors on the intake manifold or carbeurator?
-finally, i know you said only at idle, but when you accelerate, does it fluctuate at all during this time? kind of like if your stepping on the gas pedal repedely.

 

- stock d15
-no tack
-no
-no
-and no only during idle

but i will definitely check these things out and get back to you thanks!

 

start pinching vaccuum lines rite off of the manifold until the problem stops. if it's not a vaccuum leak make sure your throttle cable isn't too tight, it needs to have a little slack in it, if not your tps will not be at 0, so the computer will start ****ing with it trying to compinsate for it, and it will do exactly what your describing.

 

At idle does the idle go up then down repetedly if so could also be your Idle Air Control Valve (IACV) located behond the throttle body.

here's a link with picture to show you what i mean and a link how to clean it.

http://media.photobucket.com/image/h...cture_3678.jpg

video

http://www.youtube.com/watch?v=tUkCCwqU3eU

I think by the way you describe it below

http://www.youtube.com/watch?v=rwwgw...eature=related

Let me know man hope that helps.

 

i had too clean my iacv a few days ago it was easy

 

thanks for all the info guys but it didnt work and i also did the same thing on my si but now my si has idle problems? i cleaned the iacv and the throttle body and now my si has idling issues im stumped any other suggestions?:S

 

check the fast idle valve. its connected on the side of the throttle body and theres a hole inside the throttle body that manages the fast idle valve to maintain a steady idle. to check this stick you finger over one of the holes inside the throttle body. theres should be two holes. one the MPFI systems its on the bottom inside the throttle but the DPFI could be either the top or bottom(im not sure). try it

 

Lots of half-right info in here....

stock 90 dx has no fast idle valve, and the IACV isn't behind the intake on the dx, its on the drivers side furthest runner of the intake manifold. the farthest right when looking at it from the front.

 

http://ef-honda.com/ben/Badidle.php

 

Vacuum leak