unusual hight idle rpms...help

[spawn87]

so i im not sure what the problem is yet but every ones in a while my car will idle at about 1500-1900 rpms ....and i notice it dose it also after i turn the a/c off and if i turn it back up it will idle down but only till like 1200 rpms im taking my car in for a tunne up but dose any one have an idea of what the problem could be?

 

[Maxboost1010]

Where is your biss adjusted? Does it happen at a certain temperature? Like is it cold or hot when it happens or does temperature not make a difference?

 

[pdc]

Sounds like it could be your ISC (Idle Speed Controller).

 

[DJYoshaBYD]

Check the idle speed controller, but first, do a full timing/idle adjustment.. CAS, TPS, BISS.. go to VFAQ.com and read about it there.. Its very simple to do.. Also, give us a lil more info on when this happens.. Hot? Cold? Warmed up and stopped? Cold and coming to a stop?

 

[spawn87]

Check the idle speed controller, but first, do a full timing/idle adjustment.. CAS, TPS, BISS.. go to VFAQ.com and read about it there.. Its very simple to do.. Also, give us a lil more info on when this happens.. Hot? Cold? Warmed up and stopped? Cold and coming to a stop?

it happends mainly during hot while running and coming to a stop.

 

[90laserRSfwd]

sounds like and ISC or an air leak (t/b shaft seals, injector o rings, etc.) Mostly ISC though. Take your ISC off your car and check it with a multimeter. The ISC is attached to the T/B with two 8mm bolts. Set the multimeter to ohms, and test the coils. There should be between 28 and 33 ohms of resistance. It looks like this:

1 2 3
- - -
- - -
4 5 6

Check for resistance between 1&2 then 2&3 then 4&5 then 5&6. DO NOT CHECK 3&4. Sorry for the crude drawling, I'm not supposed to be on tuners here at work. Hope this helps. Let us know how you make out. Boss is coming, got to go, ciao..