Eating fuel pumps

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Franksmith

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I posted in the towing section because that is the main duty of the truck.

1997 K3500
7.4l 4l80e
stock except Five O Motorsports injectors and Gibson short header and flowmaster 50 series

I keep burning fuel pumps. 500 to 1000 miles (roughly).

I bought the truck with a hole in the bed for pump replacement. Ground is clean at the pump to frame. New ground cable to block. New braided grounds from engine to frame to body.

Replacing with Delphi units. New filters. New socks. new FPR. Tank is not rusted/contaminated.

Any theories to what is happening?
 

delta_p

OBS Chevrolet, When Silverado Was A Trim
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500 miles to kill it seems strange. After I bought my truck new in 96, I put 4 pumps in it in 120,000 miles. Someone told me not to run the fuel tank much below half. Since I did that, I am on the same pump as the last fix at 165,000 miles.
 

Franksmith

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500 miles to kill it seems strange. After I bought my truck new in 96, I put 4 pumps in it in 120,000 miles. Someone told me not to run the fuel tank much below half. Since I did that, I am on the same pump as the last fix at 165,000 miles.
I dont let it get under 1/4
 

JavaMan

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Check if the return line from the FPR to tank is clear. A blocked return line would cause excessive pressure.
Check voltage on the pump while running. A frayed cable would cause low voltage while pump is running but normal voltage under no load.

Sent from my SM-G965U using Tapatalk
 

blackdeathmessenger

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Sounds like a restriction in the fuel line, or possibly too big of an injector. Too big of an injector can cause the pump to overwork itself, just like a clogged fuel filter can
 

Franksmith

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Did some testing.

13.5v at the pump 14.5v at the battery

5.3 amp draw at the pump

Resistance from frame ground to pump connector and to sending unit is basically zero

The new injectors are the Five0Motorsports Bosch 19lb upgrades. The pump issues was there with the old injectors.

I may throw a new fuel pump relay at it. Is it possible the relay is weak and could be fluttering when warm or driving down the road?

Any other ideas?

Thanks
 
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