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
1 answer 5 comments
ANSWER by on 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 on July 18, 2013
CHECKED WITH A NOID LIGHT-NO SIGNAL-NO LIGHT ,NOTHING
COMMENT by on 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 on 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 on 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 on 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.