Can't Here The Fuel Pump, No Start

molsenice · January 4, 2008

I have a 94 GMC 3/4 ton, 350, 4wd. truck has always been dependable but when something goes, it takes my wallet with it.

Tonight, driving 3 blocks from work, to home, I had some major hesitation as if I was running out of gas, - had a 1/4 tank. Stopped and dumpped $40 bucks into the tank - now she won't start. Funny thing is, if I pour gas down the throught of the carb - could be a TBI - not sure, she will fire, then die.

I did notice, I no longer hear the fuel pump when I turn on the key. Got a hold of a local parts store at closing time and dumped $15 bucks into a fuel pump relay - but it did not help the situation.

It is minus 6 deg out right now, but I figured with all the gas pumps dumping 10% ethonal into the tank, I did not have a moister problem.

She is inside a warm building for the night (I'm a shop teacher) lucky me, even luckier me for the friends who came an towed me to the shop.

I do not think it is a frozen fuel line but will know in the morning. Guy at the parts store tells me the fuel pump and sending unit are in the tank and depending on which I have, it will be either 58 bucks for the pump and another 18 for the pickup screen or 248 bucks as it is one unit. Plus, I have to drop the tank to get at it.

either way, is it possible to scab in an aftermarket in line fuel pump and if so, where? - link to a thread?

Thanks for the help folks

hubbycap · January 4, 2008

Had to put a new fuel pump in my '95 5.7 TBI about a year ago. Mine didn't fail while running, but did fail to start. If it doesn't start in the am, have someone turn the key to start while someone else hits the fuel tank with a stick or something. It may bump the pump and get it going (this time.)

Mine only needed the Delco pump and screen replacement. About $52 then. It would be better if you didn't have so much fuel in that tank if you know what I mean. If you have a few guys to help, it would be easier to lift the bed up and access the top of the tank. If my tank hadn't been near empty that'd been what I would have done. Good luck.

cbxeric · January 4, 2008

The Pre 96 trucks were Throttle body injection with a low pressure fuel pump in the tank (15psi). The trucks with the Vortec injection system have a high pressure pump in the tank (55psi?). The TBI fuel pump is a lot cheaper than the Vortec pump. If you find that the pump is the problem, get one from G.M. you're rolling the dice buying one from anywhere else.

Use lots of penetrating oil on the back bolt if removing/ tilting box, The rear bolt was seized on my 90 GMC and I broke the nut loose in the channel (spin spin spin). I was lucky, I only had a quarter tank of fuel, but there was still a lot of secret rigging to get the tank out.

Good luck. Eric.

molsenice · January 4, 2008

ok - mlooks like I will pray hard tonight that the pump comes to life in the am. Lifting the bed - ha - sounds like a JOB if that comes up before dropping the tank. glad tomorrow is Friday and I have the weekend off...

well - I did have the weekend off.

thankyou for the advice folks - will post up results

molsenice · January 4, 2008

Well the truck was DOA this morning - went and spent money on parts - will be dropping the tank tonight after son's wrestling match

molsenice · January 6, 2008

Well the truck was DOA this morning - went and spent money on parts - will be dropping the tank tonight after son's wrestling match

new sending unit - lotsa work - all is well in the world - truck runs - now for the u joints, just paid 480 last year to have the fronts replaced - there toast all ready - so now I will do them myself

molsenice · January 18, 2008

well for the last 2 weeks, I have been pleasently surprised - the new fuel sending unit has made a world of differance in the truck - power like it has never had - unit musta been going bad for a while.

then today came

Started and came to work - no problem, relized I had left my glasses @ home - so made a quick trip to go back and get them - no issues with the truck.

Being Friday, we do a luncin and I happen to be the goffer - go to leave for th pizza - truck would not start - same simptoms as before (Could not here the fuel pump priming). - swapped the relay out to eliminate that - no good.

Dummped gas down the TBI - truck fired right up and died - Fuel pump is not working again, I can't believe it.

Parts store handed me another one and said for me to bring the other back in the box - but the effort involved arrrrrggghhh

well - all the parts were just removed 2 wks ago - should go smother this time - there goes another Saturday

UNreal

dwags · January 19, 2008

DO NOT buy an aftermarket pump. Only buy the ACDelco pump. Napa, Autozone and the others are junk. I've been where you are and after my troubles, only the ACDelco unit continued to work. This happened to my old 96 Silverado. Good Luck and let us know how it turns out.

molsenice · January 20, 2008

well as it turns out - the self tapping screw I used to grab ground for the new pump snapped off - didn't discover it till the tank was 1/2 way out of the truck - drilled the frame and used a bolt this time - lucky easy fix, still had to drop the tank to find, but it is runnin once again

pretty frigin frustrating

dwags · January 20, 2008

well as it turns out - the self tapping screw I used to grab ground for the new pump snapped off - didn't discover it till the tank was 1/2 way out of the truck - drilled the frame and used a bolt this time - lucky easy fix, still had to drop the tank to find, but it is runnin once again

pretty frigin frustrating

Hopefully that solved your problem. I had the same problem with mine also. When I did mine, I pulled the bed off by myself. I put eye screws in my ceiling joists. Pulled 8 bolts and used cam straps to lift it off. When I put it back on I cleaned the threads on the bed and put new stainless bolts in. Hopefully the new owner will appreciate it someday.