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5.3 Extremely low idle

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Old 01-05-2009, 01:37 PM
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Default 5.3 Extremely low idle

Hey guys.... 2000 Tahoe 5.3. About 100k on the clock. Exhaust, intake, TB spacer I think. Extremely low idle.... like 300 or so RPM. Its supposed to be about 600-650 right? Any ideas what could cause this? I can correct it with EFI LIVE I beleive but I would rather fix the problem! Thanks
Old 01-05-2009, 07:04 PM
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try cleaning the throttle body. that usually takes care of it.
Old 01-05-2009, 09:20 PM
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I've seen that before. Around 99-00 they had the recall, bulletin, whatever about the throttle sticking and it said to install a fixed orfice PCV valve and plug the hole in the throttle blade and reset minimum air. I don't know if all of the above got done minus setting minimum air or what but I have seen a handful of them idle stupidly low. To see what PCV valve you have just pull it out and see if its got a small hole in the center or a large hole with the little rattle valve inside. Also to see if the hole is plugged in the throttle blade just yank the intake tube off and see. Other then that I have no idea why they idle that low unless the IAC passage is plugged but that should cause some pretty bad drivability problems.
Old 01-05-2009, 11:11 PM
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Cleaned my Airraid filter and the MAF. Still no dice.

I think its this POS throttle body spacer - was on it when I bought it. Can it be removed and use the same bolts to put it back together or what? Easy as unbolting and rebolting?
Old 01-07-2009, 12:39 AM
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Originally Posted by SIKDMAX
Cleaned my Airraid filter and the MAF. Still no dice.

I think its this POS throttle body spacer - was on it when I bought it. Can it be removed and use the same bolts to put it back together or what? Easy as unbolting and rebolting?
Take your airbox completely off and clean your Throttle Body. My 00 hoe did this about every 50K miles. Worked like a champ for me!
Old 01-31-2010, 12:18 AM
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I've already pulled off the AEM, cleaned the TB, and now I'm down to drilling the flow hole a little bigger. I'm having the issue too. But it's only in the cold weather that this issue is more apparent.
Old 01-31-2010, 12:26 AM
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Don't drill any holes Lisa, if cleaning the throttle body didn't help, the IAC valve is more than likely sticking or shot. You could try removing it off of the throttle body and cleaning it first, and if that doesn't work it would probably be worth a shot to just put a new IAC in.

*EDIT* just for poops and giggles, pull the hose off of the fuel pressure regulator located in the center of the driver's side fuel rail and make sure that no fuel drips out. I doubt that is your problem though as the extra fuel would actually be helpful on cold start ups during the winter...
Old 01-31-2010, 12:38 AM
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Originally Posted by oldred95
I've seen that before. Around 99-00 they had the recall, bulletin, whatever about the throttle sticking and it said to install a fixed orfice PCV valve and plug the hole in the throttle blade and reset minimum air. I don't know if all of the above got done minus setting minimum air or what but I have seen a handful of them idle stupidly low. To see what PCV valve you have just pull it out and see if its got a small hole in the center or a large hole with the little rattle valve inside. Also to see if the hole is plugged in the throttle blade just yank the intake tube off and see. Other then that I have no idea why they idle that low unless the IAC passage is plugged but that should cause some pretty bad drivability problems.
The problem with the early throttle bodies sticking was from warped throttle bodies btw, and the fixed orifice PCV was the General's first attempt at combating excessive oil consumption...I diagnosed and had my throttle body replaced under warranty for the sticking condition, and shortly after the TSB came out...
Old 01-31-2010, 12:39 AM
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Originally Posted by budhayes3
Don't drill any holes Lisa, if cleaning the throttle body didn't help, the IAC valve is more than likely sticking or shot. You could try removing it off of the throttle body and cleaning it first, and if that doesn't work it would probably be worth a shot to just put a new IAC in.

*EDIT* just for poops and giggles, pull the hose off of the fuel pressure regulator located in the center of the driver's side fuel rail and make sure that no fuel drips out. I doubt that is your problem though as the extra fuel would actually be helpful on cold start ups during the winter...
What are you doing up this late young man?

Ok.. Looked that one up and it seems hardly intrusive. I think I can handle that one. And the part isn't that costly that it would suffocate me...
Old 01-31-2010, 12:53 AM
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It was my birthday so I slept late today, now I can't fall asleep lol...just trolling the site and seeing what's up


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