Fuel pump problems

[Joeyk94]

CALLING ELECTRICAL GURUS
I need your help
My 97 has had it fuel pump changed an ungodly amount of times these past 2 years, I can honestly count 10 times off the top of my head.
I’ve literally changed almost everything at first it was burning the relay up in the fuse box but not pop in the 25 amp Ecm fuse that powers it. So I pulled the pins going to it and rewrites it to a regular 5pin Bosch relay with a new power and ground. That stopped it for about 1 year prior to these last 2 years.
Then I went threw 3 in one month so I did the updated spider unit, new relay, new filter, made sure the lines were clear and took a wire wheel to every frame ground on the truck.
When I was going riding on New Years I had the heater on going 70 for about 2 hours tank was about 1/2 full. Then all of sudden it dies and won’t start on the side off the off ramp. Dropped the tank had my buddy go to the nearest orileys an warranty mine. We were back on the road again in about 45 mins. I’m to the point I can do the swap itself in about 15 mins.
Well today I had the heater on and it started to act like it was leaning out taking off from a light kinda hard. At that moment I had a light go off in my head every-time this thing kills a fuel pump either the ac or heater was on. So I turned it off and it wasn’t doing it as bad but still can tell it didn’t help it but it was fine 10 mins before.
I’ve tried a fuel pump from spectra and carter (pep boys), precision power (orileys) AC Delco and Delphi (autozone) every one of these pumps have died.
My question is could the fan from tha hvac actually be causing this, and how can I fix this?





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[Ken K]

Is your pump hanging from the fuel sender, or inside a plastic bucket? My gm service doesn't go back that far. The pump at 55 psi, should only pull 7.5 amps. Check for pinch fuel line, dirt/dust on the socket, can you blow thru the filter? I have a ton of questions, but there is a reason for your problem, we just have to get more information on what you have done or not.
Here is a photo of a guy fixing his fuel pump...

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[Joeyk94]

Is your pump hanging from the fuel sender, or inside a plastic bucket? My gm service doesn't go back that far. The pump at 55 psi, should only pull 7.5 amps. Check for pinch fuel line, dirt/dust on the socket, can you blow thru the filter? I have a ton of questions, but there is a reason for your problem, we just have to get more information on what you have done or not.
Here is a photo of a guy fixing his fuel pump...

You must be registered for see images attach

It’s hanging from the sending unit. I’ve check the lines front to back for and kinks bends or cracks. the socket is always clean. The ground is clean and tight.
Things I’ve changed
Bwd updated injection unit
Fram fuel filter
Relay power direct to battery and ground to frame
New oring on sending unit
Tight filler neck hose
Fuel tank cap was changed about 6 years ago (could be changed)
Zero voltage drop from the battery to the connector at the tank


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[kennythewelder]

Sounds like a short. Maybe this video will help

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[Joeyk94]

I’ve watched that video i don’t know how many times.
I know there has to be a short somewhere but I can not for the life of me find it


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[kennythewelder]

Oh there is a short, Im sure. You may need to start stripping back wires to find it. You could start by replacing one wire at a time, until you find the shorted one. Then tape the new wire into the harness. Solder and heat shrink every conection

 

[Ken K]

Voltage drop is a easy true way of testing the circuit with current flowing. (See youtube) Use an old headlamp in pump circuit, turn on. My question is amperage draw. Way too high if blowing large fuse. Cheaper DC amp clamps read well as compared to Fluke 87 Type5. Restriction in line, filter, bad regulator dead-heading pressure, plug pump filter-sock, pinched line all require inspection an proof of life, before moving on. That many fuel pumps don't lye.
Had customer with TBI in new 4X4 came in dealer, running 35 MPH at best. Found crimped metal line next to frame...he hit an old muffler on interstate. But did not blow fuse, just starved for fuel. There is a reason for your problem. Use the FORCE...then grab the pebble from my hand, grasshopper. Blessings & good luck. Let us all know what you find!!!