How to tell if fuel pump is going bad?
On The Tree
Joined: May 2008
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From: MIDDLE GA.
When my pump when out last year, the truck started skipping and sputtering.
Only took about 10 miles before I was stuck on the side of the road.
Try to keep atleast 1/2 a tank of fuel. The pump is actually cooled by the fuel, henceforth making the life last longer.
Only took about 10 miles before I was stuck on the side of the road.
Try to keep atleast 1/2 a tank of fuel. The pump is actually cooled by the fuel, henceforth making the life last longer.
11 Second Club
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From: Was New Orleans, but swam to Baton Rouge
If the fuel pump is going bad you should be able to see it with a pressure guage. You need to hook up a guage where you can see it in the vehicle. Then go out and do some wide open throttle passes. As you get up in the rpms you should see the pressure drop significantly.
There is a Schrader valve on the fuel rail to hook a guage in and it should idle at 58-59psi.
My ex's Suburban had a loud a$$ pump but it never went out in the 66k we had it. My Z-71 pump whines sometimes but I am not really worried about it.
My ex's Suburban had a loud a$$ pump but it never went out in the 66k we had it. My Z-71 pump whines sometimes but I am not really worried about it.
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From: Bossier City, LA
A link to the other post: https://ls1tech.com/forums/generatio...-my-motor.html
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
suburbans have notoriously loud fuel pumps. ridiculous but they keep working.
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11 Second Club
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From: Was New Orleans, but swam to Baton Rouge
If I hook a guage to it at idle and tape it to the windshield. Put it in drive, and it starts surging, (which is what happens if I don't let it warm up for awhile) Should the pressure hold steady or drop slightly due to the rpms surging? I would think it should hold steady, but don't know.
A link to the other post: https://ls1tech.com/forums/generatio...-my-motor.html
A link to the other post: https://ls1tech.com/forums/generatio...-my-motor.html
It should hold fairly steady. The real test is go out and go wide open while watching the gauge. If the pressure drops more than 10 psi you need a new pump. When my pump went out I was going from 60 psi to 35 psi under WOT.
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From: Edmond, OK
well my car wont run. i pulled the line before the fuel pump and turned the key...no gas came out. starter fluid makes my car start up. i tried to run the pump off of a battery...nothing
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From: Bossier City, LA
I changed my fuel filter yesterday and it didn't change anything. Also checked the Fuel pressure regulator hose to see if it had any fuel in it or smell like it. It was fine. So, I guess next I'll check the alternator and battery for free at the auto store. Then I'll break down and buy a fuel pressure guage.
Last edited by Hemi Killer; Dec 27, 2008 at 07:04 AM.
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From: Bossier City, LA
Thread Starter
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From: Bossier City, LA
Fuel Pressure:
At Idle - 50psi
5000 - 44-45 psi
So it is my fuel pump, right? Isn't pressure supposed to increase with rpm or hold steady? I've replaced the battery, belt, and alternator about two weeks ago. So I know it isn't that.
At Idle - 50psi
5000 - 44-45 psi
So it is my fuel pump, right? Isn't pressure supposed to increase with rpm or hold steady? I've replaced the battery, belt, and alternator about two weeks ago. So I know it isn't that.
