Disaster...need help diagnosing fuel system problem on a 1999 Chevy Silverado v-8 5.3 liter.

Asked by Nov 03, 2013 at 12:37 PM

Question type: Maintenance & Repair

This question pertains to a 1999 Chevrolet C1500 Silverado V-8 5.3 liter. First of all, I
apologize in advance for the ignorance of this whole situation. I am nothing even
remotely close to a mechanic. Ok, a fairly large amount of water was poured into my gas
tank. $20 dollars worth of fuel was added to that from what was a tank almost completely
empty. Being I am down on my luck and unemployed at this time I have tried to fix this ny
self. First I emptied out the tank by removing the fuel filter and and using the pump to
squirt it out with every turn of the key(I know it's really smart!). Any way, I did not do this
until no more fuel came out, I just measured the amount that come out and was able to
tell when enough was enough. I then replaced the fuel filter with a new one. I added fuel
and and a water removing product that also contained fuel injector cleaner. The truck
started and I assumed all was well. The next day I took off in it and it died at astop sign
less than 1/4 mile down the road. Since then, I have. It been able to start it. The battery is
now run down and today I tried tinkering with it and I immediately notice  that when I
turned the ignition to listen for the fuel pump, I heard a series of loud strange humming (
electrical) noises coming from my fuse panel inside the truck and then traced the sound
to the fuel pump relay located in the fuse box under the hood. Whew! I guess the
question now is: bad relay or bad fuel pump and relay? Thank you to anyone willing to
take the rind to read and give an answer.

5 Answers

okay...there are a couple of no-no's goin' on here....Number one --NEVER run the gas tank EMPTY...what happens is the fuel pump will overheat and fail...sounds like it ran out of gas and shut down....par-bakin' the motor and am surprised that it still runs...this might be the a moanin' and a groanin' that is happening....nothing we can do except replace the pump...WATER...crikes, how on earth did water get in there? a little kid with the garden hose on an unlocked fuel cap (DavidH25's kid) ruining the injection system causing replacement of all injectors and fuel system components? https://www.google.com/#psj=1&q=1999+Chevy+Silverado+v- 8+5.3+fuel+pump+relay

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relays could hum...but would quit altogether with a voltage-drop (like a corroded 1/0 connection from battery to frame)...I got a source for you, but it's an undervoltage condition created by the firey 300 amp connection of the dis-similar metals (lug and frame) sharing MANY amps thru a single spot...again and again "dulling it down" creating a semiconductor layer of corrosion...this seems to happen on every car anymore...some have TWO 1/0 cable ground connections one for the startermotor and one for the delicate ECU and fuel pump and components ~ All or NONE is the M.O. of the relay....the pump can be fightin' as a wounded soldier tho, if it gives with the fuel pressure would just turn up the stereo or news broadcast and forget it.~

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a can of HEET will convert any water into a burnable substance~

I hope that you DRAINED the tank before you tried puttin' more gas in there....another NO-NO...drain everything with the drain plug....use it for 50/50 mix for your snowthrower~ start fresh with a can of heet and 93 octane and hope for the best....on this subject~ DavidH25 ended up replacing the motor~


Even the smallest amount of water will wreak havoc on a computer controlled engine. I'd suggest draining the gas tank, dropping the gas tank, cleaning the gas tank, replace the fried fuel pump, remove the fuel line at the fuel rail on the engine, blow the fuel line out with compressed air, put it all back together, put some gas in it, and add a bottle of heet or dry gas to your next two tank fulls. HTH. -Jim

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