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Followup To
Question -
I have a 1992 Buick Skylark with the V6 in it. I beleive it's the 3300? My problem is that the fuel pump does not come on when you turn on the ignition key. It always had before and the car started fine. Now the car does not start obvioulsy because there is no fuel getting to the fuel rail. I did a voltage check on the plug leading to the fuel pump and found voltage present. Leading me to believe that the fuel pump in the tank was bad. I replaced the fuel pump but still have the same problem. Fuel pump does not come on. I've looked for bad grounds, blown fuses, broken wires. Found none. The car turns over fine and I'm sure there is no other problem other than the no fuel issue. In the past it did have a tendancy to just stop running after the car was driven for about 30 minutes. But 5 minutes or so later it would start up again just fine. Then run well. Looking for suggestions for what else could be causing the problem. Thanks for your help.
Answer -
If you have voltage on the plug leading to the fuel pump at the last connector at the gas tank and your POSITIVE you have a good ground source, The pump has to run. Are you positive that the pump is wired correctly when you installed it.
Did you test the pump to make sure it is NOT faulty ?.
Fuel pump test:
1. Get yourself a helper.
2. remove the gas cap.
3. have one person listen in the gas tank at the gas cap opening.
4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.
5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.
6. Does it ?.
If you do NOT hear it run, in most cases the fault is the fuel pump.
let me know.
autohelp
I checked the ground at the battery which had two wires leading off of it to the body of the car. Cleaned those up good and they seem fine. No broken or frayed wires. The last connector for the fuel pump has voltage present, wires are good. All tested good continuity while I had the gas tank down from the car. I did listen at the gas tank for the pump to come on but no sound at all. I'm 99% sure all wiring is correct. Are you saying the new fuel pump I put in could be faulty? What about ignition modules? or ECM?
Thanks for your quick reply.
AnswerIf you have battery voltage to the FUEL PUMP WIRE at the fuel tank connector and the GROUND is ALSO OK then the pump has to be faulty or you accidentally forgot to attach one of the wires to the pump.
You have no choice but to remove the tank and check the pump.
Here is how the fuel pump circuit operates:
As soon as you turn ON the ignition switch to start the engine a 2 second ONLY battery voltage signal is sent from the computer to the fuel pump relay and from the relay back to the fuel pump in the fuel tank. This runs the fuel pump for ONLY 2 seconds of which pressurizes the fuel system in preparation to start the engine.
Once the engine starts, The computer BYPASSES the fuel pump relay and sends constant contionous battery voltage from the computer to the oil pressure switch of which is now CLOSED because the oil pressure is UP because the engine is running. Therefore the battery voltage flows thru the oil pressure switch back to the fuel pump to run the fuel pump constantly until you turn OFF the engine.
autohelp
