man, that valve is expensive.. I checked the vaccuum line that runs from the fuel rail to the top of the intake manifold.. its good.. no cracks or anything, where else should I be looking?
man, that valve is expensive.. I checked the vaccuum line that runs from the fuel rail to the top of the intake manifold.. its good.. no cracks or anything, where else should I be looking?
may have carbon buildup on the IAC valve, a bad TPS or MAP sensor, or just a vacuum leak somewhere. Is your brake booster hissing while the engine is idling? Even a dirty EGR valve can cause high idle issues.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
When you pulled the vacuum line off did you check for fuel out of the regulator (on the rail). Usually doesn't cause the condition you've noted but it's an easy check. I'd lean towards a vacuum leak from the intake gaskets. Spray some break cleaner or carb cleaner around the base of the intake at idle and see if there's a noticable change in the idle speed and/or smoothness. Clean the throttle plate and MAF sensor. Pull the IAC out of the throttle body and make sure the passage is clean.
There wasn't any in the line from the fuel regulator up when I pulled it off.. I'll go ahead and try and run down those list of things that you gave me.. poke around.. see if I can't find something wrong.. I'll let you know how things go. Thanks for the help guys.
I have the same problem in my 98' tahoe I'm gonna go get some carburetor and choke cleaner and go to town.
EDIT: Oh whoops gasguzzler already mentioned this.. In much more detail. Do as he said that is the problem that needs to be solved.
Last edited by blackcoffee; 02-11-2009 at 08:53 PM.
Finally got around to fooling with it.. It's been so windy the past couple days that I didn't even want to go outside. Sprayed carb cleaner everywhere.. all portions of the intake, checked MAF.. looked good.. tb at IAC had no blockage. all connections are good, no wires are bad.
Poissbly in load shed mode? This is when the BCM and PCM decide the voltage is low and they work together to shed electrical loads and raise the idle. Maybe engine protection mode? If the PCM thinks the engine is overheating it might do stuff like that.
Just a couple shots in the dark but you'll need scanned and logged (or snap-shotted with a TechII) to really know at this point.
Actually about a week and a half ago, went to go start my truck, flipped the key.. got nothing, no lights anything, couple minutes later, it started but was running very rough. The positive cable was loose.. tightened it up.. Got to love side posts.. Do you think that may have anything to do with it? You said something about voltage drops..
Mine did that exact same thing this morning. Wouldn't start. Went inside, Went back out and tried again for sh!ts and giggles and it started. Sounded more like a chopper trying to take off though. Thump Thump Thump Thump Thump Thump. Almost like I had a really Lopey cam.
Check engine light has been on for a while. Last time I had it read left and right bank lean. Don't know if that has anything to do with it. Still haven't changed them.
Could be. Take the cables off and remove the red and black boots. Make sure you get the cable ends clean before reinstallation. Replace the bolts if they're corroded.Originally Posted by 4444xxxx4444
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