i would also like to add the isle changes every time u come to a stoplight or just let off thee accelerator and the car is in neutral but it doesnt really bounce around and input appreciated

If this Biss screw is all the way down, you might want to check the o ring behind it to see if it's in good shape. A broken BISS screw o-ring would cause your problem. There's also the matter of your ISC.

Have you checked to see if your intake manifold gasket is leaking?

Originally posted by GSX90
Have you checked to see if your intake manifold gasket is leaking?

Click to expand...

hmm, would that cause the idle to do that? i am having the same problem. the biss screw is all the way down and only goes as low as 1k, i also get idle surge when the fans come on and the hood is shut. so maybe air if getting pushed in there? not sure if that could cause it, but i havn't checked that yet....


edit: i have had the isc changed, tb cleaned, checked for leaks, bought a new biss screw w/ o ring and nothing has worked. where can i get an new gasket?

You might have a bad computer. Ultimately, your computer controls your idle. It also controls the voltage regulator inside of your alternator. When your fans kick on the ECU tries to regulate your idle accordingly. It may be having problems doing this. If the problem's not in your ISC, then the only place I can think of where turning on your fans would cause idle surge would be your ECU or maybe your alternator. The alternator or battery can start going bad without your charging lights coming on. It did that to me. Only when the idle dipped really low did the charging warning light come on. That didn't happen until it was almost ready to give up the ghost for good. I'd pull your computer and look to see if the capacitors are leaking too. I did have an idle surge problem, but it was an improperly set BISS screw.

well, the last guy who owned my car had the ECU replaced. it has only about 10k on the ECU. it was done by a shop who specialized in turboed cars. i have no idea, it doesn't really get to me that bad. how expensive is changing the caps?

my valve cover gasget is leaking a little just spray off oil from the lifters tho and the gaskets around the spark plugs are fine the idle does dip low when i turn assessories on like the rear defroster then immediatly goes back up to 100o like it was before and the biss srew wont come out of the hole its all the way unsrewed but i cant lift it out anyone know how to get it out?? also has the car gets warmer the idle increases to a maximum of 1200 but changes everytime i let off the accelerator and come to a stop when i first adjusted the screw it went down to 800 then a few minutes later went back up to 1000

mine does the same thing as yours. it completely strange. i have no idea what is causing it.

to get the screw out, just unscrew it all the way, then chew a piece of gum until it gets all sogy and sticky, then press it over the screw and lift up . kinda ghetto, i know, but it works.

ya the screw head is a little stripped im not sure if the o ring is leaking i just want to get my idle down so it can stop annoying me i dont the the the leaky valve cover gasket would have anything to do with the slightly high idle tho there tying to charge me 85 just for the gasket anyway are u sure it could be the isc i am going to check the resistance tomorrow to make sure there all at 30 kohms but i was just thinking a dirty thrtle body would be the main culprit and input appreciated thanx

The easiest way to get the screw out to replace the o ring is to buy a magnet on a stick. You can get one at your local auto parts store and they only cost a few dollars. If you do alot of your own repares and upgrades I garuantee it will come in handy.

I suggest taking the TB right off and poke the back of the screw with something thin,but stiff (I used a coat hanger),and it should pop out with a bit of force..I tried everything people suggested to me and nothing worked.First I just tried backing it out a whole bunch of times but obviously it only comes out so far,then stops.Then I tried a magnet on a stick..Came to the conclusion that the screw is copper so a magnet won't help.Tried gum and that didn't work.I even tried super gluing a Philips bit to the screw but that didn't work...Just my .02 cdn.

Personally I have not run into this problem yet. I will remember that when this problem does arise. I was not aware of the fact that the screw was made of copper.

the gum thing worked for me.

when i pulled the old screw out it was copper or metal (don't know) and the new one is plastic? maybe they sent me a 2g screw which is just as good, but maybe they are plastic?

Should be an aluminum BISS Screw