alright guyz im in need of some tips. my neighbor owns a 90 crx si. im not sure if hes runnin a stock motor but im pretyy sure is a y8. well the thing is when he starts it and its at idle the car's rpms go up and down. from 600-1200 only at idle. im a mechanic so the first thing i thought was the Idle air control sensor. but my homeboy told me his 91 accored with an f22 had the same problem but it was reving up and down with hight rpms and he said a vacume line was disconnected. so which one could it be?

 

it could be either.

also check for coolant loss. a bubble in the coolant system will do that as well.

 

two thing I know are common to that problem, the IACV plunger is sticking because it is old, and filled with crap from the intake, a bad vacuum line (listen for hissing as you turn it off), or a mispositioned throttle sensor. check all of those out.

 

okay but wouldnt you hear the hissing if the car was running?

 

explain to me how a a bubble could cause it to have a bad idle

 

it has to do with how it the air bubble goes to the IACV? and makes it screw with the idle. there are posts on this. just search for IACV.

 

hey i have the same problem with my car if you figured it out could you reply on this page what you did? thnx... later bro'

 

sure no problem

 

it was the IACV. i took it out and cleaned it with some carb cleaner. then put it back on. now it idles just right

 

alright thnx im going to try that when i get home.. later bra'

 

koo den. let me know how it goes