Kahuna6719

Yeah I have been considering that, after all the parts I have replaced recently I don't really have $190 for a reman. VCM then another $100 or more for a dealer to flash it for me. What is the EEPROM chip and doesn't it come with the new one.

EinST

Darn, I meant the PROM chip (for knock sensor calibration). You'll want to transfer it over even if the replacement VCM comes with one (e.g., from a junkyard).

wishiknew

Do you know when this started happening? Was it before or after you replaced the catalytic converter?

RacerX

I suspect the ignition switch in the steering column may be your problem.

Kahuna6719

Problem solved finally! After all the replacement parts camshaft sensor, crankshaft sensor, ignition control module, fuel pump, fuel relay, air cleaner, new ground straps from engine to frame, pump to frame, ign. coil, plugs, cap, rotor,wires, coolant sensor. It all came down to the fuel filter. I did not suspect this due to replacement about 6 mos. ago when I replaced the first pump(aftermarket). This second pump I put in 2 weeks ago was a Delphi, I recommend after all the research I did with Chevy's having fuel pump problems do not skimp on an aftermarket pump.
My conclusion for the stalling was a combination of poor ground wires, aftermarket pump, arcing plug wires, fuel filter that did not allow enough pressure at higher speeds. Another trick that helped me discover the bad plug wires was to wait until dark, pop the hood, start the engine and then observe. This allowed me to easily see the sparks from the arcing wires. It was strange because even with bad wires my truck never ran rough, had lack of power or misfired.
What gave me a final clue to cracking the problem was hook up a fuel pressure gauge on the the fuel rail, tape it to the windshield and observe the fuel pressure during a stall while driving. As the truck stalled the pressure dropped right down. This helped me eliminate the VCM. Also I pinched the return line to the tank and the fuel pressure did not spike. This test eliminated bad fuel pressure regulator.
So the last thing I suspected was another bad pump, but before dropping the tank and ripping the pump out for the third time, I decided just for the heck of it I would change the fuel filter again since I had a new one handy. If you remember earlier I replaced that only 6 mos. and not many miles ago. After installation I fired it up went for a ride for several hours with no stalling. Woo Hoo! After having these problems I now have a good understanding on how my 97 5.7L operates. All the components from the ignition system to the fuel system and all the sensors that are controlled by the VCM (computer). Every part is vital to running properly. I appreciate all the suggestions from everyone. Hopefully this information will help someone else with stalling problems and things to check.

EinST

Congrats and thanks for the update. Great tips, also.