fuel ignition system

Asked by Jun 21, 2009 at 09:22 AM

Question type: Maintenance & Repair

engines runs for 20minutes and stops - it seems to have fuel presure - have tried three different computer modules with the same results.

1 Answer

12,195

Not really giving us too much to go on here bud ... Seems to and does have fuel will help a lot. When it dies .... Go to the fuel rail of the engine and there will be a fuel pressure tap on the rail ( black cover ) Turn the key on and you should here the fuel pump run for three seconds - go to this tap and press the valve ( Its like a tire valve ) and there should be a real good squirt of gas come out of it ( Stand out of the way of course : ) ) ( 40-47 pounds of pressure if you have a tester ) If it does then we know it really has fuel - Then we are down to injector pulse / And Spark. Go to the easiest injector to get to and remove its harness. Get a regular test lamp, key on, and check for 12 volt power on ONE of the wires. If no power then its probably a fuel pump relay. If power is there we will check the ground on the other wire that does NOT have power - Use the test lamp again with someone turning the engine over - the test light should be connected to Postive of the battery and the other end to the injector wire - the test lamp should light intermittantly on /off /on / off. If it does the PCM is good and the engine has fuel / If it does not then we have to next look at what the PCM is looking for - The crank signal.. That is basically the fuel circuit ... if everything checks out here - then it is most likely loss of spark. Get a inductive timing light and put it on one of the ignition wires ( does not matter - the easiest one ) and have someone turn the engine over while the timing light is on - It should flash on and off .. If it does not we have found Our problem .. in the distributor - Ither the Distributor Pick Up or the Ignition Module. My Guess would be the Fuel Pump relay or Ignition module both of which are heat sensitive Good Luck

Your Answer

Pontiac Experts

  • #1
    tenspeed
    Reputation
    11,490
  • #2
    Tom Demyan
    Reputation
    9,300
  • #3
    Js08016
    Reputation
    8,390
View All

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.