[ChevyTruckGuy]

Originally Posted by 40 grey

Thanks to all for their help and suggestions. After further testing and retesting, the EGR valve was found to be intermitantly sticking open when solenoid commanded it open(cruise over 40mph). Oddly enough it would manually test okay, held vacuum, and pintle moved freely off the truck. When on the truck it would sometimes not seat or open freely after it was hot. New one(ac-delco) is coming tomorrow. Hopefully this is the problem. ---

---BTW, it ran pretty good with automatic ecm and prom. Low idle(500rpm), and shift light on steady were only observed problems.-----

That is what I was thinking was wrong! But with out the 3 shop manuals I don't know how you new everything was working correctly? Not unless you have the 3 shop manuals? Also here is a good site for trucks and mods www.fullsizechevy.com

Craig

[40 grey]

I do not own the GM manuals. I do have an old, well used and trusty Motors manual. But I do have access to the GM manuals through work. Through these and an old Snap-on scanner most things can be observed/tested, even if it is done crudely! I have a fair amount of experience with junk and low budgets.

[ChevyTruckGuy]

Originally Posted by 40 grey

I do not own the GM manuals. I do have an old, well used and trusty Motors manual. But I do have access to the GM manuals through work. Through these and an old Snap-on scanner most things can be observed/tested, even if it is done crudely! I have a fair amount of experience with junk and low budgets.

Thats good you have manuals because with out them is just guessing I found that out the hard way! Go to the web site one of the best for chevy trucks!

[40 grey]

UPDATE: EGR valve finally showed up and was installed today. Made sure passages were clean(it was). Night and day difference. Problem is completely gone and truck is smooth again! Thanks to all who offered help, it never hurts to have more info.