Fuel Pump busted ?

[ColoradoSilverado]

Yesterday I was driving home when my truck stalled, tried starting it, engine turns over but no go. I suspect the fuel pump, is there a way to test it without removing the fuel pump ?

Bert

[rjeffery]

Put a fuel pressure gauge on it, and see if it is pressurizing the system. The port for the gauge is on the pass side, on the line that supplies the fuel rail (you may have to remove the plastic Vortec cover to access it). Do a full test as follows:

Specs are 55/62 lbs of pressure
Here is some guide lines of fuel pressure checking.

Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 55-66 fuel pressure.
Cold start should be 55/62 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Engine running should be 55/62 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
If pressure does not come up with return line pinched or blocked off.
Go to fuel filter and hook a gauge direct to a line at fuel filter.
Pressure should come up to 75 or more and will hold after fuel pump is turned off.
If it leaks down there after fuel pump is turned off it is LEAKING BACK THREW PUMP CHECK VALVE OR PUMP MODULE LINES.
Post back your fuel pressure readings.
(Copied from MT)

[knogoodidleft]

on my 5.3l when i put the key to run position you can hear what i belive to be the fuel pump pumping, not sure but its really loud, have somebody put there ear up to the tank and turn the key see if they hear anything

[silverado122775]

just because you hear the pump, does not mean it is working properly

[ColoradoSilverado]

Originally Posted by knogoodidleft

on my 5.3l when i put the key to run position you can hear what i belive to be the fuel pump pumping, not sure but its really loud, have somebody put there ear up to the tank and turn the key see if they hear anything

Yes, I used to hear my fuel pump too but now there's no sound. Did some checks according to my Haynes Manual and what's left to check is the wiring harness and the pump. My neighbour told me about a uel pump wiring harness issue on these Silverado's ? Anyone else heard about this ? Due to work I won't have time to look at it untill saturday afternoon.

Bert

[Bob B]

Yes I also saw it first hand.
A friend's 97 Tahoe was having pump issues, and he found that he could bang on the bottom of the tank it would go again. The pump was replaced, then we went to the desert. in our camp area it wouldn't start.This time we dropped the tank and found a pin in the connector was burned, apparently from poor contact.
The guy who replaced the pump didn't look at it when he pulled the plug.
So we stole a pin from the underhood lamp and swapped it into the plug.
Later while I was at the counter of my local NAPA counter, I noticed a poster on the wall showing the exact problem and warning to not replace the pump without checking it.
The one style of plug is updated to a different type for better reliability.
Bob B

[ColoradoSilverado]

Well, turned out it was he pump. Dropped the tank, replaced the pump which came with a different plug and a new wiring harness. The whole job wasn't too bad just the fact that ofcourse the tank was more then half full.
Truck started right up !

Bert

[NoRiceHere01]

I know this thread is pretty much ended now, but for future reference: on these stupid trucks the answer to your actual question is 99% of the time YES, the fuel pump is busted.the pins do occasionally go bad, but the pumps almost always go bad.i've been at work having things delivered from the supply place and the pump went bad in the delivery guy's 2500 on the spot.mine went and it was replaced and im pretty sure the new one is junk too.I feel so bad for all these people having to figure out if the pumps are bad.GM should reimburse every silverado owner now for the pumps, whether they've been replaced or not.if you havent replaced it yet, do it anyway.an ounce of prevention is worth a pound of cure.you can conveniently spend $300 to do it now, or wait till the truck is sitting somewhere and has to be towed at midnight.I hope some GM execs read this stuff and think about it before selling their new truck with these pieces of garbage in the tanks

[ColoradoSilverado]

Originally Posted by NoRiceHere01

I know this thread is pretty much ended now, but for future reference: on these stupid trucks the answer to your actual question is 99% of the time YES, the fuel pump is busted.the pins do occasionally go bad, but the pumps almost always go bad.i've been at work having things delivered from the supply place and the pump went bad in the delivery guy's 2500 on the spot.mine went and it was replaced and im pretty sure the new one is junk too.I feel so bad for all these people having to figure out if the pumps are bad.GM should reimburse every silverado owner now for the pumps, whether they've been replaced or not.if you havent replaced it yet, do it anyway.an ounce of prevention is worth a pound of cure.you can conveniently spend $300 to do it now, or wait till the truck is sitting somewhere and has to be towed at midnight.I hope some GM execs read this stuff and think about it before selling their new truck with these pieces of garbage in the tanks

Does anyone know if the new Silverado has the same set up ? What about the transmission, do they still have the crappy 4L60E in them ?

Bert

[Bob B]

Originally Posted by NoRiceHere01

I know this thread is pretty much ended now, but for future reference: on these stupid trucks the answer to your actual question is 99% of the time YES, the fuel pump is busted.the pins do occasionally go bad, but the pumps almost always go bad.i've been at work having things delivered from the supply place and the pump went bad in the delivery guy's 2500 on the spot.mine went and it was replaced and im pretty sure the new one is junk too.I feel so bad for all these people having to figure out if the pumps are bad.GM should reimburse every silverado owner now for the pumps, whether they've been replaced or not.if you havent replaced it yet, do it anyway.an ounce of prevention is worth a pound of cure.you can conveniently spend $300 to do it now, or wait till the truck is sitting somewhere and has to be towed at midnight.I hope some GM execs read this stuff and think about it before selling their new truck with these pieces of garbage in the tanks

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Hi,
My 97 pump was fine fir 110,000 miles before it failed.
I had it replaced then in a year the replacement carter went bad (out of warrantee) then two more went bad in warrantee. I did the last two myself and last one was a Delphi the new name for ac delco.
I have learned that supposedly the pump will have a short life if you run the tank too low too often especially in hot weather.
The latest one has been going now for over a year, no more running on less than a quarter tank.
The failures were all different in details, Original one just died, the second one the motor froze on it, third one the check valve went bad.
I now carry the pressure gauge in the under hood tool box along with a jumper wire for the pump test pigtail.
Bob B