Idle Issue

uthnkunome · February 15, 2009

I have researched through google and by talking with others and have came to the conclusion that the idle issues on the chevy trucks may be an easy fix.

When coming up to a stop sign or redlight the truck is fine until i stop. The rpms with go down and little bit then return back to normal range. I have heard that cleaning certain parts with carb cleaner will fix this problem.

Does anyone have detailed pics or is there a sticky topic around here that addresses this issue or atleast a step by step instruction write up that will help me. I plan on doing this one day this week when i have time. I have about a half can of carb cleaner and an old tooth brush.

I also plan on going to the autoparts store and buying a service manual for my truck.

2003 chevrolet 1500. 4.8

uthnkunome · February 17, 2009

well i put new plugs on it today and they gave me the wrong pcv valve so i headed back to the parts store. It stalled out on me twice and this has never happened.

When i got back i cleaned out the throttle body a little bit by just spraying it in there while my wife had it idled up some. I also sprayed some MAF cleaner in the MAF sensor. I started it back up and drove it around some and everything is back to how it should be.

KENNHON · February 18, 2009

well i put new plugs on it today and they gave me the wrong pcv valve so i headed back to the parts store. It stalled out on me twice and this has never happened.
When i got back i cleaned out the throttle body a little bit by just spraying it in there while my wife had it idled up some. I also sprayed some MAF cleaner in the MAF sensor. I started it back up and drove it around some and everything is back to how it should be.

Wish i had read your post sooner.... my idle, and light cruise problem, was cleared up just like yours[my Throttle blade has a hole in it[7.4L-'96], and it was completely plugged[130,000miles]... i got some 3M cleaner, and every thing is ok now

dorman68 · February 18, 2009

Check your intake manifold or intake manifold gasket for vacuum leaks.

1stLtDan · September 24, 2009

Check your intake manifold or intake manifold gasket for vacuum leaks.

Intake Gaskets: even when a vacuum guage shows it holds good vacuum; the IAC motor will do all it can to compensate for issues until it burns itself out by staying fully extended. Very small squirts of carb cleaner along the intake manifold will tell you pretty quick where your vacuum leak is. Usually the engine will bog down or die out. I could not depend on the computer to show any codes at all and the engine would die at times at a stop or going from park into a gear on the automatic transmission. Old GMs usually need intake tightened down if you can get the accessories un bolted enough to get to the intake bolts. If that doesn't help, keep spraying around your vacuum hoses, egr gasket, tbi base gasket, pvc hose and power brake hose and pipe fittings. Usually you can spray out the carbon in the throttle bodies and it clears up idle issues. IAC pintal end gets carbon on those. On a cold engine a IAC motor will get hot pretty quick trying to keep air from passing through yet you have to catch that before the motor finally burns itself up. Good luck to all who read these.