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Fuel pump issue - Printable Version

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Fuel pump issue - m-wilhelm - 01-20-2011

Car died on the road Sunday, jumpered the DME relay, measured 12v at the fuel pump and no noise. I replaced the fuel pump, drove the car for 3 hours the next day, today I died on the road again. Jumpered the DME relay, have 12v at the pump and no noise. I'm sure its possible the new fuel pump died, but could something else cause the fuel pump to die? An electrical problem somewhere else? A suction problem or vent problem in the tank?



I have the line from the fuel pump to the fuel filter disconnected, 12v to the fuel pump with no noise, and no fuel comes out.



I replaced the fuel sender in the tank and the fuel screen in the tank recently. The old fuel sender was broken bad with many small pieces in the tank, could a piece floating in the tank block something else? Where do the 2 hoses on the top of the fuel sender go?



I could replace the fuel pump again but I'm afraid something else is causing the problem.

Fuel pump issue - 94SilverCab - 01-20-2011

Quick question...you were waiting for a DME Relay, did you ever receive/replace that yet?



Jay

Fuel pump issue - m-wilhelm - 01-20-2011

I have 3 DME relays and I've tried the hard wire jumper which bypasses the relay and powers the fuel pump. I'm using the wire jumper to power the fuel pump for testing.

Fuel pump issue - flash - 01-21-2011

you know that the DME relay jumper is a 3 point jumper, right?

Fuel pump issue - m-wilhelm - 01-21-2011

Yes on the jumper 87, 87b, and 30. Tried running the old and new fuel pump straight off the battery, both act the same. They make a quick buzz when first powered but not a continuous noise.



I'm having a hard time believing a new fuel pump died in 3 days, I guess I will return it and get another one. I even cleaned several ground points to make sure it wasn't a weird electrical problem.

Fuel pump issue - DaveN - 01-21-2011

I spent the last 4 nights upgrading ADSL nodes on the street to be capable of handling VDSL IP television delivery. I had one bad card from a repair depot and one bad brand new card - in a row! These are multi-thousand dollar cct cards that underwent rigorous testing (that's what the cereal box said). So the moral of the story is, you guessed it, a new fuel pump made in god knows where could probably fail.

Fuel pump issue - Eric_Oz_S2 - 01-21-2011

Any debris in the tank can kill the fuel pump. If this caused your first pump to die, then it may have also killed your replacement. You can either flush and drain the tank or try installing an inline fuel filter before the pump - at least temporarily - to capture the remainder of debris in the tank.

Fuel pump issue - m-wilhelm - 01-21-2011

I replaced the screen in the tank right before the first fuel pump died. I checked last night and there is some debris in the bottom of the tank again but the screen looks perfect. I didn't see any debris come out of either fuel pump or hoses when I disconnected them. Also the fuel filter is new.



What kind of inline filter could I put between the tank and pump? The hose from the tank to the pump is very short, I'm going to replace that hose with the next pump.

Fuel pump issue - banditsc - 01-21-2011

Debris will kill the pump, that's why I suggested to run the pump backwards to try and push anything logged in the pump out and see if it spins the other direction.

Fuel pump issue - m-wilhelm - 06-22-2011

Another fuel pump just died on me, that's the 3rd broken pump this year. What could be causing fuel pumps to break besides debris?



Just before the first pump died I replaced the fuel filter. After the first pump died and before the second pump I cleaned out the fuel tank and replaced the fuel screen inside the tank just before the pump. The second pump died 3 days after install. Right after installing the 3rd pump I removed the charcoal canister system and added a vent line which fixed a hesitation problem. Now the 3rd pump died 5 months and about 500 miles later, car had been running fine. After sitting for a couple days it started and then stalled, won't start, and fuel pump tested bad.



Could a bad fuel filter cause a pump to die? I replaced the fuel filter just before any pumps died. I'm going to order a new filter and take the old one apart to see if I can find anything inside.



Could a bad fuel pressure regulator cause pump issues? How can I test the fuel pressure regulator?

Fuel pump issue - flash - 06-22-2011

a bad filter can absolutely cause the failure - so can bad gas - water in the gas will do it too - the cheaper fuels, like "big box store" gas is notorious for causing problems



i think i would pull the pump apart though and determine if it is contamination or an electrical failure or something else altogether

Fuel pump issue - DaveN - 06-22-2011

Probable that there is a common electrical issue causing bad VDC supply and burning out pump?

Just a guess but 3 pumps!

Fuel pump issue - flash - 06-22-2011

that's my thinking too - that's why i suggested taking the pump apart to determine the failure

Fuel pump issue - RS Barn - 06-22-2011

I was a rep for Airtex fuel products. Most FP failures were due to debris in fuel system. A very small particle (5 microns) could damage impellers.

My Factory rep had a cool machine to test flow with and without load. When we tested Pumps in front of techs, they were pissed. They wanted the pump to be the problem, not pump damage. This leads me to my next point. How did your techs test pump? If it just doesn't work I'm leaning toward electrical issue.

Fuel pump issue - m-wilhelm - 06-22-2011

I might be able to get the pump replaced under warranty so won't be able to take it apart. Took apart the fuel filter and found some black specs maybe rubber. I'm going to replace the hose from tank to pump, check valve, hose from pump to filter, and new filter. Going to drain and check the tank soon.



I cleaned some ground points after the second pump died. Anyway to test for possible electrical issue?



Anything else to try?

Fuel pump issue - m-wilhelm - 06-22-2011

I put in a DME jumper and no fuel pump noise. Then I removed the pump and connected wires directly to the battery. The pump makes a short buzz when connecting wires but then quiet. I've tried reversing wires to pump in the opposite direction and same thing, quick buzz then quiet. All of the dead pumps reacted the same.

Fuel pump issue - jaacco - 06-23-2011

Check your charcoal venting canister in the left front fender. If it has failed it might be the source of black debris in the tank.

Fuel pump issue - m-wilhelm - 06-24-2011

The charcoal canister was bad and I removed that system after the 2nd pump was installed. The black stuff in the filter does look like the charcoal, I'm a little surprised that charcoal could make it past the in tank screen.



Time to clean out the tank.



Would adding another small filter between the tank and pump hurt anything?

Fuel pump issue - DaveN - 06-24-2011

You already have the Porsche Uber filter tank side so I am not sure another smaller filter in-line would accomplish much. If you have your original filter still cut it open and have a look see. It is possible you clogged your new one already but I doubt it.

Fuel pump issue - Mark - 06-24-2011

Would adding another small filter between the tank and pump hurt anything?



'Twas recommended to you earlier in the thread.

[quote name='Eric_Oz_S2' timestamp='1295598244' post='103849']

Any debris in the tank can kill the fuel pump. If this caused your first pump to die, then it may have also killed your replacement. You can either flush and drain the tank or try installing an inline fuel filter before the pump - at least temporarily - to capture the remainder of debris in the tank.

[/quote]