10-14-2019, 06:04 AM
one can even drive all week with the DLC Diag jumper in place, and see 12 all week and then on moment bam , new code pops.
cold idle can be 1000 to 1500 rpm colder the block that faster.
hot is 800 with all accessories off. (means no AC on this car)
many things cause failed idle regulation.
coolant not hot, 180f.
TPS idle switch not closed, and at 0vdc. if 5vdc idle is cancelled.
air leaks. (aka vacuum leaks from anywhere to the plenum)]
ECU in limp home mode. not 12, means that , mostly.
if way below 800 even 400 , egr main valve leaking like mad.
leaking injector or clogged, may cause low idle speeds. below 800 hot.
misfiring engine, blew 800.
1000 hot, no AC turned on is ISC is off line or stuck open.
or engine super rich and huge vacuum leaks at the same time.
The ECU wants to control idle at 800 hot and aggressively modulates the ISC valve to do that. we see it can do that. only why remains.
cold idle can be 1000 to 1500 rpm colder the block that faster.
hot is 800 with all accessories off. (means no AC on this car)
many things cause failed idle regulation.
coolant not hot, 180f.
TPS idle switch not closed, and at 0vdc. if 5vdc idle is cancelled.
air leaks. (aka vacuum leaks from anywhere to the plenum)]
ECU in limp home mode. not 12, means that , mostly.
if way below 800 even 400 , egr main valve leaking like mad.
leaking injector or clogged, may cause low idle speeds. below 800 hot.
misfiring engine, blew 800.
1000 hot, no AC turned on is ISC is off line or stuck open.
or engine super rich and huge vacuum leaks at the same time.
The ECU wants to control idle at 800 hot and aggressively modulates the ISC valve to do that. we see it can do that. only why remains.
http://www.fixkick.com