idle problems after intake install
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so should i pull the damn thing again or just keep lookin for the vaccum leak? i cant hear any type of vaccum hissing noises in the engine bay with the car running.
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had a friend come over with a scanner.....no thrown codes and no vaccum leaks anywhere, all vaccum hoses have vaccum. the brake booster releases pressure when the hose is unplugged, pcv hose has vaccum and sucks.
when we started the car, it shot to 3000 rpms for a second, then dropped down to a very low idle, real choppy. we gave it gas to keep it alive and then it held its own idle at 700 for a while, backfiring about every 5 seconds. then it slowly idled back up to 2000 where it stayed. the scanner said it had 25 degress of spark advance at 2000 rpms which we thought was funny....and that was the only abnormality that we could find anywhere.
the car was tuned about a month ago, and about 6 degrees of advance was added to compensate for the pulled timing that the bad knock sensors were causing......could this be a tunning issue? we dont think so but who knows....lemme hear some more input.
when we started the car, it shot to 3000 rpms for a second, then dropped down to a very low idle, real choppy. we gave it gas to keep it alive and then it held its own idle at 700 for a while, backfiring about every 5 seconds. then it slowly idled back up to 2000 where it stayed. the scanner said it had 25 degress of spark advance at 2000 rpms which we thought was funny....and that was the only abnormality that we could find anywhere.
the car was tuned about a month ago, and about 6 degrees of advance was added to compensate for the pulled timing that the bad knock sensors were causing......could this be a tunning issue? we dont think so but who knows....lemme hear some more input.
Last edited by kyles2000z; Feb 12, 2007 at 11:43 PM.
Your tune isnt gonna make the car idle at 2k. Just because the hoses have vacuum does not mean there is not a vacuum leak anywhere. It can have a vacuum leak and still have some vacuum left.
You had a good idle, you then pulled the intake, you replaced the intake, and now your idle is really high. Its common sense it is a vacuum leak. make sure you hooked up all the vacuum lines when you put it back together. After that pull the manifold again and check it out.
You had a good idle, you then pulled the intake, you replaced the intake, and now your idle is really high. Its common sense it is a vacuum leak. make sure you hooked up all the vacuum lines when you put it back together. After that pull the manifold again and check it out.
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theres only 2 hoses that are big enough to cause the rpms to jump up like that and these hoses suck very hard and have full vaccum, the small vaccum hoses wouldnt be very noticeable if there was a leak there i dont think. there are no vaccum noises in the bay whatsoever. my dad cant figure it out either and hes been doin this every day for 30 years now. oh well, ill post up when i figure somethin out or find a possible problem.
Just FYI, you can have a vacuum leak on these engines and not hear it. It has happened to me before. My fuel trims were way up and eventually I found a vacuum leak that i couldnt even hear.
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wel the car is at a friends shop now, i did all i can and im gonna leave it up to him now, he can do alot more thani can, ill post up waht was wrong with it wheni find out.
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well the verdict was that when i put the intake manifold on, BOTH times, i managed to get one of the wires caught under the corner of the manifold and it wasnt allowing it to seal all the way. just goes ot show how small a vaccum leak it takes to throw things waaay off. thanks for the help tho guys!
Glad ya got it fixed. 
