Idle Problems

[SweetNLo]

ya...

what happens if you hold the brakes for an extended period of time then release them and stomp on the gas? does it go or does it almost die? if it dosent go you are probably dealing with a failed vacume brake booster.

honestly lately like over the last year there have been many people with these ideling problems.... my burb completely ruptured its brake booster last year.... scary **** coming to a stop sign while also blowing the front passanger line.

Anyways after I put a new brake booster on my truck it immediately had so much more power than it ever did and it was obvious to me that I had gotten used to a gradual decline in performance due to this faulty leaking BB.

I think all of these boosters in everyone's trucks are reaching the end of there life and because it is a brake part we dont realize it until after trying many other things....

Al

My Dad and I tested the vacuum line on the brake booster. We unplugged the line from the booster itself and sealed it while the truck was in drive. Unfortunately, the truck still surged at idle. Therefore, the booster line is not the problem. I was really hopeful that this was going to be the problem. Thanks for the suggestion.

 

[Schurkey]

The only thing you need then is the plug for the manifold where the tube connects. To plug EGR pipe hole in intake, use GM 12556596 or a 10AN plug. The valve can open and close, but it'll do nothing. I suppose you could plug the vacuum source, too. Then the valve doesn't open.

Yes, I think it's a bad idea to disable the EGR.

 

[reservoir dog]

Gonna bump a 2 week old thread. My CEL was coming on at light steady throttle no load conditions, had the 32 egr code, but the truck ran and idled great, I removed the egr valve and noticed someone had plugged the vacuum port and reinstalled the hose. I installed a new ac delco valve. The truck ran like crap, had the exact symptoms you describe. Rough and surging idle , sometimes it would die at stoplights. I put the old plugged egr valve back on and its runs and idles great again, been 3 years now.

 

[Schurkey]

My CEL was coming on at light steady throttle no load conditions, had the 32 egr code, but the truck ran and idled great, I removed the egr valve and noticed someone had plugged the vacuum port and reinstalled the hose. I installed a new ac delco valve. The truck ran like crap, had the exact symptoms you describe. Rough and surging idle , sometimes it would die at stoplights. I put the old plugged egr valve back on and its runs and idles great again, been 3 years now.

Wild Guess: Your EGR solenoid is stuck open, and/or the vacuum hose is plugged into the wrong port.

I bet you have lots of knock-sensor activity, retarded timing as a result, and therefore poor fuel economy and power at cruise.

 

[reservoir dog]

My guess is a PO plugged the port at the diaphragm to get it to run correctly and get through emissions. Truck runs great has more power than I would expect from 200hp and gets as good of mileage as any other V8 I have ever owned. This is not my first rodeo.

 

[SweetNLo]

Gonna bump a 2 week old thread. My CEL was coming on at light steady throttle no load conditions, had the 32 egr code, but the truck ran and idled great, I removed the egr valve and noticed someone had plugged the vacuum port and reinstalled the hose. I installed a new ac delco valve. The truck ran like crap, had the exact symptoms you describe. Rough and surging idle , sometimes it would die at stoplights. I put the old plugged egr valve back on and its runs and idles great again, been 3 years now.

Thanks for the post. I'm going to have to perform some experiments on the truck. I tested the donor engine's EGR valve on the truck a while back and it ran similarly to how it runs now (surging, etc.). I might try plugging the vacuum port just to see what happens.