Idle problems
#1
Idle problems
I've got a 1985 that varies its idle RPM from 550 to 750, in park and in drive. Car runs great above 750 rpm. New plugs, cap, rotor, and MAF sensor. Can't detect any vacuum leaks. I was told that the 1985 did not have a power or burn-off relay for the MAF sensor. Any ideas. Thanks.
#2
RE: Idle problems
Vacuum leak. 100% probability.
https://www.corvetteforums.com/m_37283/tm.htm
print it out, put it in the bathroom.
https://www.corvetteforums.com/m_37283/tm.htm
print it out, put it in the bathroom.
#4
RE: Idle problems
ORIGINAL: lbelew
I've got a 1985 that varies its idle RPM from 550 to 750, in park and in drive. Car runs great above 750 rpm. New plugs, cap, rotor, and MAF sensor. Can't detect any vacuum leaks. I was told that the 1985 did not have a power or burn-off relay for the MAF sensor. Any ideas. Thanks.
I've got a 1985 that varies its idle RPM from 550 to 750, in park and in drive. Car runs great above 750 rpm. New plugs, cap, rotor, and MAF sensor. Can't detect any vacuum leaks. I was told that the 1985 did not have a power or burn-off relay for the MAF sensor. Any ideas. Thanks.
#6
RE: Idle problems
Thanks for all of the input. I guess I'll try cleaning the throttle plates next. I read the article and tried the propane with no luck of locating a vacuum leak. The car has 30300 miles on it and is like new except for my idle problem. I've set my idle at 700 rpm in park and the car purrs, but at 500 it surges to 700. What do you guys think of an EGRissue. I currently do not have any codes stored or a service light. By the way I also have a 2000 and a 1979 vette. Thanks.
#8
RE: Idle problems
30K doesn't seem like enough distancefor avacuum leak to develop. I can't imagine carbon build-up either.
...or anything else failing, mechanical-wise. Rubber and other organic fiber compounds - vacuum hoses and gaskets,COULD fail, given the time period.
So I gotta' stick with an intake leak somewhere. Get back on this one tho'... I'd really like to know on this one.
...or anything else failing, mechanical-wise. Rubber and other organic fiber compounds - vacuum hoses and gaskets,COULD fail, given the time period.
So I gotta' stick with an intake leak somewhere. Get back on this one tho'... I'd really like to know on this one.
#9
RE: Idle problems
I agree with cleaning the throttle body and the IAC also. You can usually hear vac leaks....like a hissing sound.
Does it make a difference if the engine is cold or hot? Usually a vac leak will disappear once the ECM goes closed loop.A easy test to do if you have an ohm meter is to check the resistance of the injectors hot and cold.
Does it make a difference if the engine is cold or hot? Usually a vac leak will disappear once the ECM goes closed loop.A easy test to do if you have an ohm meter is to check the resistance of the injectors hot and cold.