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


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

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