pcmentor

Can anyone tell me how the ISC works and how to test it. The ohm reading checks out. I am troubleshooting a low idle problem when hot and in gear. have checked the TPS and EGR. What other things can make the idle low?

NCSU-4runner

dunno if its anthing like a supra ISC but this is how you do it for a 7M

when i checked mine the movement is VERY subtle, you almost have to have someone else ground the points while you stare at the part that moves


http://www.cygnusx1.net/Supra/Librar...on=FI&Page=107

frty6&2

Your MAF sensor could be off, dirty, or broken or you could have a vacum leak, or your timing chain could have jumped a tooth if the chain guide is broken, which they usually are. And I have no idea how the ISC valve works, I just turn the screw till the idle is around 800-900 and roll. Good luck,

Mike

pcmentor

The idle somehow is now at a good level. I fixed it some how. Thanks for your input. Pete

pcmentor

I'm not having idle speed problems now but I get a miss at 2500rpm. Replaced all tuneup stuff. The O2 sensor voltage is around .19vdc at idle and goes up to .45 at 2500. The O2 also throws a code if left at 2500 rpm for two minutes. Must be lean for some reason. Fixed major vacuum leaks but still low voltage. Any help will be appreciated. Thanks