ISC problem that needs to be fixed!

[soyee7]

My cel has been on in my car for a while, i posted on this a while ago but that was when i thought it was only a fuel trim malfunction. I went to an actuall dealer the other day and they ran it on there scanner and it said it was my idle speed controll that was messed up. I changed my ISC and the light still came back on. Is there anything else that could be realated to my idle speed controll.

[kjewer1]

Any time the ECU cant control idle speed you'll get the code. MAke sure your TPS is properly adjusted on a 2g, and the throttle closd switch works on a 1g. Fix any vac leaks you have. Set the BISS properly. Thats the tough part. You need a way to konw that the ISC is centered and then adjsut the BISS accordingly. DSMlink lets you do this, not sure if any 1g loggers do. The mitsu scan tool is supposed to have a function for this but I could never get it to work. Just make sure the ISC can hold 750 rpm. IF it cant adjust the BISS so its in control, and go a half turn too far (if you had to adjust it). If the light keeps coming back its something else.

[soyee7]

how long does it usually take for a check engine light to go off by itself.

[kjewer1]

It is never supposed to go off by itself according to the OBDII standards. Has to be cleared with a scanner, or by removing power from the ECU.

[RiceRocket18]

hey, i have exactly the same problem. i replaced my ISC and the CEL still came back. my ISC did have a bad resistance number so i guess it was good to replace it. and it did help the idle. however, the problem is still not fixed. now the car idles fine at 750 but ocassionally still drops below 750 and stutters and comes back up. it does this sometimes when i stop at the light, do a sudden stop or just shifting from neutral or park back to drive. i have an A/T. my CEL code says something like "Idle Control System Malfunction" (or somewhere along that line, can't remember the exact words)

i unscrewed my BISS and checked the rubber o-ring and it looked fine. it doesn't seem to be coming loose anyways. it screws in/out just fine.

could dirty TB, TPS, or EGV valve cause this CEL?

[kjewer1]

TB could, TPS wont, not sure about EGR. I'm assuming you checked leaks as well?

[RiceRocket18]

ok... thanks. i think i'll just have the mech do it next time i go in. i dont feel like taking off the TB myself. going in next month to get my new torque converter and shift kit put on, i'll just tell them.

thanks.