90 awd idleing prob. . . . . . stumped??

[dragdsm]

when cold it will idle at 2000 then when it warms up it will go anywhere from 900 to 1500 or 1500 to 2300 . . . . any suggestions??? also when getting into boost right about 6 psi it will kind of hesitate then go to 9 psi where it normally goes any suggestions on that too??

 

[snailed]

vacuumme leak/ buust leak, check all vacuumme hoses, BISS screw o-ring, throttle body shaft seal. best way is to pressure test the system. hook compressed air into the system, fitting onto a cap and clamp it to teh pipe usually right off the compressor outlet into the I/C pipe, set the compressor to a bit over the PSI of boost you will be running (i do 35) listen for leaks, if you can't pinpoint it spray some soapy water solution on the area and it'll bubble up where the leak is. PS if you put too much pressure and the compressed air/ cap blows off it'll be LOUD. hope this helped.

 

[playitlouddsm]

Get yourself a multimeter and test your TPS and IAC. If one of those are out of spec your idle won't be steady (aka idle surge).
-Good Luck, Nick

 

[larsrya8]

set the compressor to a bit over the PSI of boost you will be running (i do 35) listen for leaks

If you're still stock, between 20 and 25 psi should be fine. It's usually recommended to set the test pressure slightly (~5psi) above what you plan to run. I'd only do 35 if you're trying to create more leaks were there aren't any yet.

My ISC (Idle Speed Controller) was bad, and that's what caused my idle surge.