WHY WILL CAR NOT RUN UNLESS I SPRAY FUEL DIRECTLY INTO INTAKE- SPARK IS STRONG. on 2002 Pontiac Grand Prix

FUEL RAIL PRESSURE IS AT 45 PSI-HAVE CHANGED ICM,CRANK POS SENSOR, PRESSURE REG, MASS FLOW SENSOR. THE ONLY CODE STORED WAS FOR THE O2 SENSOR. NO OTHER CODE STORED. I SUSPECT THE PCM,BUT DON'T KNOW PROPER PROCEDURE TO CHANGE IT. PLEASE HELP AND THANKS!

by in Waterloo, AL on July 16, 2013
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1 answer 5 comments
ANSWER by , July 16, 2013
Check for injector pulse with a noid light! Post results. Need this info. first! If you dont have the GM MPFI noid light, parts store may rent/loan you one. Dont have the pressure specs here, but best i can remember that's enough. (45 psi)
COMMENT by , July 18, 2013
CHECKED WITH A NOID LIGHT-NO SIGNAL-NO LIGHT ,NOTHING
COMMENT by , July 18, 2013
Most likely the ecm injector driver is defecfive. Need to check the circuits to be sure ,once you buy this preflashed computer, it's yours! You need a wiring schematic for testing! If there is a shorted circuit you may fry the new ecm also. If there is an open circuit you can repair that! Good luck with it.
COMMENT by , July 19, 2013
IF THE CIRCUITS CK OUT GOOD-I WILL REPLACE THE PCM THAT HAS BEEN PRE-FLASHED. MY QUESTION IS, DO I NEED TO HAVE IT REPROGRAMED BY A GM DEALER AFTER INSTALLATION? AND IF THE PCM IS THE PROBLEM, AND THE REPLACEMENT IS NEEDED, WILL IT RUN TO THE DEALER SHIP TO HAVE IT REPROGRAMED,OR WILL I HAVE TO TOW IT TO THE DEALERSHIP. I AM A RETIRED MECHANIC, BUT DO NOT HAVE VERY MUCH EXPERIENCE WITH PCM OR ECU'S. THANKS AGAIN
COMMENT by , July 19, 2013
Call parts store, some can be done pre purchase and all you have to do is install. You will need the vin and computer numbers.
COMMENT by , July 19, 2013
Call parts store, some can be done pre purchase and all you have to do is install. You will need the vin and computer numbers.