High idle

[nickvash0104]

Thanks for your help thus-far; still need to check out the ISC but not really enough time with Rita about to slam into the coast here; hopefully I'll have some time to check it in the near future.

I forget, but isn't the ISC a testable part electrically? I know that carbon buildup on the sensor will cause problems, but I'm not sure if the valve itself has gone bad yet.

[rnoswal]

The part can be tested. Suprrrrrrra-girl, whoops too many r's, had a link to a service manual that would probably tell you exactly what to test and the values. I have a cd service manual, but I can't figure out how to copy it to here. Ask her for that link.

Russ

[nickvash0104]

I'd adjusted the screw - you're talking about the one near the throttle body, right? I adjusted it to the lowest RPM position and it's still idling too high (I knew it was the lowest RPM position because the other direction revved the engine higher)

[WiseAssJester]

The cams still stock? On a larger motor a massive cam will bump the idle up. My 350 has to idle at about 11-1200 after warming up to keep the lope from the cam from killing it.

[nickvash0104]

Yep, still stock - only thing that isn't stock in regards to engine parts is the air filter.

[rnoswal]

If you have that idle adjuster screw all the way in then you have either an air leak or the ISC is not functioning. You can hear the ISC clicking when you turn the A/C on and off, it should do a little clicking, but that still won't guarantee that it is working. If the computer senses that the car is always cold then it will keep the idle up too, there is a sensor for that too. Still sounds like a vacuum leak though. Make sure that the screw you were playing with seats in all the way too. Sometimes all the carbon build up won't allow it to seat when screwed in all the way. Also, if all else has been checked, the brake booster could be leaking air. Just pinch off the hose to it to check that one out.


Keep trying!

Russ

[KingDiamond]

You can always do the old carb cleaner test, and give spritz here and there to see if the idle changes. Spritz around the intake, and vacuum lines, and what not, if you get a change in your idle when spritz it in a certain area, then that is where your vacuum leak would be.

[nickvash0104]

=( No suction of the carby spray along the intake / TB assembly... not sure where else my leak would be at if I'm suffering one. I did notice though that the idle has reset itself slightly, now idling at the mid 800s - still higher than stock. Would having the K&N cone filter distort the idle w/o a different MAF sensor?

[rnoswal]

800 is very close to what you want. But if your idle adjuster screw is turned all the way in then it is still not right. You might want to check the butterfly screw to make sure someone else hadn't screwed it in to get it to idle up. Also make sure the cables aren't too tight to let the butterfly arm comes back all the way closed. Sometimes the butterfly screws can come loose and not the the butterfly close all the way. It is just barely supposed to be off the sides of the intake to prevent sticking. Did you try closing off the brake booster vacuum hose?

Let us know.

Russ

[suprra_girl]

what were the results of your compression test?

do you still have high idle?