UNCONTROLLABLE IDLE....HELP!!!!

[Ameer Antar]

sounds like you have a vac. leak somewhere....if you're absolutely sure the 
throttle isn't stuck, sometimes the return spring on the throttle can get 
gummed up and stick. The vac. leak is prolly between the throttle body and 
cylinder head. There's a lot of stuff to check here...like ISV valve hoses, 
oil cap...basically anything that gets vacuum. A vac. diagram would help. 
Since the idle screw is doing nothing now, and since the idle screw is 
really just a small vac. leak, there must be another bigger one somewhere 
making any idle-screw adjustment insignificant. This can be intermittent 
too, if the hose is rotted and moving around. good luck.

-ameer


At 11:08 AM 3/1/2001 , you wrote:
>Hi all
>I just had the weirdest thing happen to my 87 5kcsqt, while driving home 
>last night exiting the freeway, pulled up to a stop light, noticed the car 
>is idleing at 3000 rpm...try to kick the throttle down...maybe its 
>stuck...nope. So I wait until this morning to check and see if the idle 
>screw has worked its way loose....nope. Checked all hoses(visually with a 
>good feel) to see if any are cracked to make for a vaccum 
>leak....nothing....checked the throttlebody to see if it's 
>sticking....nope....checked the throttle cable to see if its getting bound 
>up....nope;(. The Idle screw seems to have no affect at all!
>     The only thing I can think of is.. a couple of weeks ago my mechanic, 
> tweeked my fuel/air mixture so I could pass emmisions, was running too 
> rich, leaned it out a bit ....haven't had it tested yet....then last week 
> my fuel pump took a crap.. so I replaced it. I've checked for any codes 
> that maybe stored., but nothing is coming up!! I really need your help 
> gang, I haven't the faintest clue what this could be?????Thanks for any 
> input in advance.
>
>
>Thanks
>Tim