Fuel Pump Problems

[tdb420]

Hi, I replaced my fuel pump with a unit from autozone last summer and it just went out a few days ago. It is still under warranty so i swapped out my fuel pump for another one I got at autozone and installed it. When i turned the key to the on position i couldnt hear the fuel pump turn on and the car wouldnt start so I assumed that I just got a bad one. I went back up to autozone yesterday to swap out this fuel pump and I got a another one, this fuel pump only made it about 2 miles of driving before failing and now my truck is stuck at the store. I think it is a remanufactured fuel pump that i got from autozone and I think that may be the problem. Has anybody else had this problem before or have any advice as to how I can solve this problem.

 

[tdb420]

Also I checked the voltage at the fuel pump and it is at 11.6 when the fuel pump primes and I can feel and hear the relay click when the key is turned to the on position. Right now i can get the fuel pump to prime and run the engine for a second or two but then it sputters out like it isnt getting fuel so i am pretty sure the pump is the problem.

 

[MrShorty]

I would expect even cheap autozone pumps to do better than that. I'd be tempted, before dropping the tank again, to check a few things out:

1) How does that 11.6 V compare to battery voltage? There shouldn't be a lot of voltage drop between the battery and the pump: maybe you have a bad connection somewhere in the fuel pump circuit that is interfering with the pump's operation. I'd be tempted to look over the circuit and see if there's a specific spot that is the source of the voltage drop or not.

2) I'd almost certainly put a fuel pressure gauge on it, just to see if the engine is dying/not starting due to lack of fuel. There's a "mini-diary" in Under the Hood with some basic fuel pressure tests you can try to see what the fuel pump is up to.