Chevrolet Repair: Fuel Pump, purge cycle, fuel pump relay

Question
QUESTION: New fuel pump on a 2002 Trailblazer will not run after a purge cycle.

ANSWER: HI JOE,CK FOR POWER DOWN AT THE FUEL PUMP HARNESS PICK LEAD,[GREY WIRE] SHOULD HAVE POWER WHILE CRANKING THE ENGINE  AND 4 SECONDS AFTER TURNING THE KEY OFF. IF NOT CK FOR POSSIBLE FAULTY FUSE OR FUEL PUMP RELAY IN UNDER HOOD FUSE BOX...IF RELAY AND FUSE IS OK POSSIBLE WIRING PROBLEMS. WHEN YOU PUT THE NEW FUEL PUMP IN ARE YOU SURE YOU CONNECTED ALL THE WIRES GOOD AND TIGHT..IF THERE IS POWER ON THIS GREY WIRE WHILE CRANKING MAY HAVE A BAD PUMP OR PUMP NOT INSTALLED CORRECTLY...BY PURGE CYLCLE YOU MEAN AFTER THE FIRST 3 OR 4 SECONDS YOU LOOSE FUEL PRESSURE AFTER RELEASING THE KEY  ??? LET ME KNOW HOW THIS GOES,,,TOM

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QUESTION: I have replaced the fuel pump and it works great through the 'purge' cycle with a good flow and pressure. So the relay is working and the wiring is good. (Idiot proof connectors.)
I did the purge cycle until the tube that feeds the injectors is full. It will run until that fuel is gone then stops. At the time it is running the accelerator will NOT work to increase the R.P.M.s.
The throttle body is spotlessly clean.
I have replaced the fuel regulator and computer. Had it flashed and the dealer said that they had no idea and I was to pay up $600.00 and take it home. So that is where it is at.
Another towing bill.
This car has made the best of them humble.

Answer
HI JOE, OK SO YOU HAVE GOOD FUEL PRESSURE...OK THIS SOUNDS LIKE A BAD THROTTLE POSITIONING SENSOR OR BAD THROTTLE BODY ITSELF..WHEN IT STOPS DOES IT HAVE FUEL TO THE FUEL RAIL OR NO. DOES IT HAVE PULSE TO THE INJECTORS WHEN IT STALLS..I NEED TO KNOW THIS..USE A 194 LIGHT BULB AND BEND THE CONNECTORS AND PUT THE BULB IN ONE OF THE INJ PLUGS TO CHECK FOR A PULSE WHILE CRNNKING THE ENGINE OVER..IF NO PULSE YOU MAY HAVE FAULTY PCM...HAVE YOU CHECKED FOR ANY RECENT CODES IN THE PCM ??? I CAN NOT BELIEVE THE DEALER WOULD DO THAT TO YOU !!!! THEY SHOULD OF RUN A DATA TEST WITH THERE SCAN TOOL TO CK THIS FURTHER FOR YOU..IT IS NO WONDER WHY PEOPLE DO NOT LIKE THE DEALER..GET BACK TO ME WITH WHAT I NEED TO KNOW WHEN IT STALLS OUT....GOOD LUCK TOM..