Truck stalling at stop and turning - Hi all, I am new to the site and want to thank anyone in advance for any help...I have 2003 GMC sierra 1500 ...

Hi all,
I am new to the site and want to thank anyone in advance for any help...I have 2003 GMC sierra 1500 with the 4.8L. My truck will stall out at stop lights and when turning at very low speeds. The idle floats between 1000 rpm and down to 0 sometimes it will recover but most of the time when it starts acting up it will just die out. I just changed the fuel filter but it is still having the same problem. This problem is not consistent either, it will happen when the engine is hot, cold, on start up, after a long drive, it really seem to have a mind of its own but it is starting to happen more and more as time goes on.


Thanks again

Sounds like the idel speed control valve may be bad.

Has it thrown any codes

where is the idle speed sensor to check and no it hasn't thrown a single code. I wish it would so I would atleast have a starting point besides change one thing after another and hope it stops. Thanks

I would start with the basics, starting with vacuum lines. You can try pulling a vacuum line and if it doesn't change the idle or stall then you may have a vacuum leak.

The idle speed control valve is on the throttle body. I relaced one on my neighbors silverado. It was doing basicly whay yours is doing. Be sure to clean out the carbon from the throttle body really good if/when you replace it.