Loud whine, brand new fuel pump.

[hefftone]

More driving.....
Starts out pretty good, but after about 30 minutes its the same sad song.....only enough juice to idle. And it has to sit for a little bit...damn near left me stranded.
Rock@uto is replacing the pump under the @CDelco warranty.
Before removing the pump, I am doing some electrical troubleshooting. Voltage drop on the + side is about 1.3 volts and that is just probing the wire on the outside of the tank. From what I've heard, more than .5 volts dropped in a circuit is unacceptable. Maybe thats why these truck go through pumps....? I am contemplating running a new heavier gauge wire to power the fuel pump.


Also the truck keeps running if the relay is unplugged. The maniall says this means there is a faulty oil pressure switch.....there is nothing attached to my oil pressure switch. I don't even know where the wire is. Can somebody explain that, I'm having a hard time wrapping my head around how, and why it is supposed to work.

I had it idling for a bit, and it sounded like it was getting weak again. When I blipped the throttle, there was a little hiccup/backfire followed by this strange whistle...I left it going and when I found the, I pulled off the air cleaner, and there was a f**King flame in the the passenger side throttle bore!!!!!! Holy crap....went out when I shut off the motor.

 

[SAATR]

More driving.....
Starts out pretty good, but after about 30 minutes its the same sad song.....only enough juice to idle. And it has to sit for a little bit...damn near left me stranded.
Rock@uto is replacing the pump under the @CDelco warranty.
Before removing the pump, I am doing some electrical troubleshooting. Voltage drop on the + side is about 1.3 volts and that is just probing the wire on the outside of the tank. From what I've heard, more than .5 volts dropped in a circuit is unacceptable. Maybe thats why these truck go through pumps....? I am contemplating running a new heavier gauge wire to power the fuel pump.


Also the truck keeps running if the relay is unplugged. The maniall says this means there is a faulty oil pressure switch.....there is nothing attached to my oil pressure switch. I don't even know where the wire is. Can somebody explain that, I'm having a hard time wrapping my head around how, and why it is supposed to work.

I had it idling for a bit, and it sounded like it was getting weak again. When I blipped the throttle, there was a little hiccup/backfire followed by this strange whistle...I left it going and when I found the, I pulled off the air cleaner, and there was a f**King flame in the the passenger side throttle bore!!!!!! Holy crap....went out when I shut off the motor.

For the running issue after the relay is pulled, I would look at the possibility that you are getting power from another circuit, as in an ignition hot wire and your fuel pump power wire have rubbed off their insulation and are shorting to one another, providing power for your pump when there should be an open circuit. May also help explain the large voltage drop. I would definitely upgrade your power AND ground wires to the pump, as these are one of several reasons that quite a few of these trucks like to eat fuel pumps. As far as the tank goes, you may be better off simply replacing it. For a hundred bucks, it may not be worth the hassle of HOPING that you cleaned it enough THIS time, ya know?

 

[Rusty Silence]

I just bought a truck that had a new fuel pump (cheapie) installed a few days before. It was really loud after running for awhile and would get louder the longer it ran and the hotter it was outside. It was so loud sometimes I could hear it inside the cab while driving down the road. At first the power would fall a little flat when floored but after a couple of weeks it got so bad that after driving for 30 minutes I could only use about 25%-10% throttle. It's a 96 5.0 vortec and was reading 50 psi. I had it swapped out for an AC Delco and now it's super quiet and runs great.


Btw, that pump was so loud it sounded like a vacuum cleaner.