Fuel Pump

[gpdriver21]

I have a 95 Pontiac Grand Prix SE with the 3.1 L engine. Yesterday i went out to my car and it started up then idle strnagley and a few seconds later shut off. I determined that the fuel pump is gone and the car has 107,000 miles on it. When i turn the key to oon i dont hear it like i use to before, it makes no noise now. I have tried tapping it with a hammer and still no luck.

I am pretty sure the pump is external, i would just like to make sure it infact is not inside the tank and that i was tapping on the right thing.
Its located in the back by the bumper on the drivers side right, it has two hoses going into what looks like a canister???
Does anyone know how hard it is to replace on your own? Any directions on procedure would be great!!

Thanks in advance!

[JonJon68]

I don't know if your fuel pump is internal or external but what you were tapping on sounds like your fuel "filter".

[richtazz]

Your fuel pump is in the tank. What you were tapping on is your evap canister. Under the hood, there should be a test lead near the fuel pump relay. If you apply 12v to the test lead and the pump kicks in, then you have either a bad relay or a bad oil pressure switch. The relay should energize when you turn on the key to prime the fuel system, then after the key is returned to the run position and the engine is running, the relay gets its signal thru the oil pressure switch. If the oil pressure switch is faulty, the car will start, then either immediately shut off, or start to stumble, then quit. IF applying 12v to the test lead doesn't kick the pump on, then the pump is bad.

[gpdriver21]

Could you tell me where the oil pressure switch is and what it looks like?? What is the reasoning for having the oil pressure switch control the fuel pump?

I was able to get the car home, when i went back it started right up. I did replace the fuel filter on it tonight and had one heck of a time getting it off. Not sure when it was last done, but it looked like it was a while ago. Can it be an intermitten problem with the fuel pump where it will come on and off before it goes bad?


Thanks Again!!

[richtazz]

The fuel pump is wired thru the oil pressure switch to protect the engine if low oil pressure is detected. If oil pressure drops too low, it cuts the fuel pump to prevent seizing the engine. A bad fuel pump, as with any electric motor, can be an intermittent problem. Normally whacking on the gas tank with a rubber mallet (don't use a steel headed hammer, fuel + spark = BOOM!!!!) will get the fuel pump going again until it finally craps out for good.

[gpdriver21]

Thanks for the info!! I went out to my car this morning and it didnt start. But atleast I got the car home without getting it towed. Right now its got a full tank of gas in it too. Maybe if i am lucky i can get it to start tonight and drive around to burn some of it out. Its probably a 18 gallon tank is my guess. I will attempt dropping a new pump in this weekend. I will let you know how i make out. Anyone got some ideas on how to get the gas out? Is it possible to syphon?

Thanks for your help!!

[gpdriver21]

Well the whole project was a success!! Syphoing the gas out of the tank took about 2-3 hours. Ended up having to pull off the small line that goes to the filler pipe and then put the syphon hose in there.

For anyone else whos gotta syphon out there tank, dont try putting a hose in the filler pipe because theres a ball inside the tank where the filler pipe connects to and you dont want to break that.

Once the gas was out it wasnt that bad of a job. It took about 5 and half hours once the gas was out to drop the tank, open up the tank and replace the pump then put it back up. The bolts for the straps were a bit hard to get off from the years of dirt buildup on them. As expected getting the straps back on was somewhat hard. Luckily i had a second jack to hold up the tank while i tugged on the straps to get the bolt to start on the strap. The car seems to run smooth with the new pump. I thought it would of been harder to do this job, but it wasnt! Guess shes good to go for another 100,000 miles!

Thanks guys for all your help!