Help Engine idle speed and stalling

[westcasey]

I need help! I have a GMC R1500 throttle body injected pickup. I have had it in the shop several times. The thing keeps stalling when you put it into gear. The mechanic drilled out the idle adjust screw and moved it around. Turned it up way too high. Now I have a guy that is trying to solve the problem instead of cover it up and we can't find what the original engine idle speed is supposed to be.

With the timing set dead on what its supposed to be the truck pings on acceleration dies when you put it in gear. The EGR valve has been replaced; there are no vacuum leaks. Knock sensor is working correctly. What else could this be?? Its been hooked up to the computer and everything passes.

Would appreciate any possible suggestions.