Fuel Issue (pump?)

[truckintim05]

Hey everyone. It's been a long time since I've come to visit the forum, but I'm so glad y'all are still here.

'94 350 2wd

Lately I rarely drive my truck. It sits in the garage, and driven less than 100 miles a year. It's about time for my inspection again. It may have been last years inspection since I drove it last, I'm not sure. Today I tried to fire it up, and it wouldn't start. It cranks, but no fire. I can hear the fuel pump priming when the key is turned. If I put starter fluid in the throttle body it'll go for a second or two though. There is no fuel coming from the injectors if you watch while cranking it. I was hoping for the easy fix and replaced the fuel filter first. While filter was off, I turned the key to 'run' just to see how the pump flowed, and everything seems fine. Fuel went everywhere. Reconnected the lines, and cycled the key a few times to get the fuel back to the TB. Then...still no start. I removed the the fuel line at the TB and cycled the key again, but never could get fuel up to the open line at the throttle body. I can hear fuel moving in the lines somewhere, but never spilled out.

At this point I'm thinking the pump is just weak, and doesn't have enough pressure to get the fuel up there. Before I remove the bed (full tank), and replace the pump and sending unit I wanted some extra input. Is there anything I'm missing here? I guess the only other option is going to Harbor Freight to get a gauge to actually test it, but I'd rather not.

Thanks for any help.

 

[skylark]

Blow air through the line from the filter to the tb.

 

[Schurkey]

I removed the the fuel line at the TB and cycled the key again, but never could get fuel up to the open line at the throttle body. I can hear fuel moving in the lines somewhere, but never spilled out.

You removed "THE FUEL LINE" at the throttle body??? There's TWO sets of plumbing--supply and return. If you removed the return tube, of course you didn't get fuel out of the tube.

You should have had some spill out of the hole in the throttle body, though.

If the fuel pump can't produce enough pressure to un-seat the fuel pressure regulator, you won't have fuel spraying out of the open fuel return port.

You hear fuel "moving in the lines somewhere"? First Guess: Rotted hose on pump output nipple, inside the tank. There could be enough of the hose left to spray fuel with the fuel filter disconnected, but not enough to hold enough pressure to run the vehicle.

 

[truckintim05]

You removed "THE FUEL LINE" at the throttle body??? There's TWO sets of plumbing--supply and return. If you removed the return tube, of course you didn't get fuel out of the tube.

You should have had some spill out of the hole in the throttle body, though.

If the fuel pump can't produce enough pressure to un-seat the fuel pressure regulator, you won't have fuel spraying out of the open fuel return port.

You hear fuel "moving in the lines somewhere"? First Guess: Rotted hose on pump output nipple, inside the tank. There could be enough of the hose left to spray fuel with the fuel filter disconnected, but not enough to hold enough pressure to run the vehicle.

I'm certain I removed the supply side, not the return, according to my manual. It was the smaller diameter hard line (passenger side of TB). Either way, pump or rotted hose in the tank, looks like I have to pull the tank or the bed to access it. I already bought the full pump/sending unit, so it should take care of both. I never had any fuel spill out near the throttle body regardless. Its dry as a bone. I assumed when I removed the filter that gravity was enough to drain it from the supply line. I will try blowing compressed air through however just to be sure there is no blockages.

When I say I can hear the fuel moving through the lines when it was open at the TB, it's almost as if the fuel came up the line a bit, then as soon as the pump stopped "priming" it would flow back towards the pump again afterwards. glug glug glug like. Hope that helps.

Thanks for the input.

 

[89RCLB]

Supply line is on drivers side of the TBI...

You must be registered for see images attach

 

[TheBeast]

This is just a thought, when my 94 started doing this, a whack on the tank with a hammer would get her to fire up. Fuel pump was dead. Also, if you’re a long bed, I highly suggest dropping the tank. When I removed my bed to do the pump, good god! Would have been easier to do the tank, the long bed is ridiculously heavy!

 

[truckintim05]

Supply line is on drivers side of the TBI...

****, y'all are absolutely right. that's why i love you. thanks

 

[94burbk1500]

This is just a thought, when my 94 started doing this, a whack on the tank with a hammer would get her to fire up. Fuel pump was dead. Also, if you’re a long bed, I highly suggest dropping the tank. When I removed my bed to do the pump, good god! Would have been easier to do the tank, the long bed is ridiculously heavy!

You don't actually have to remove the the bed, remove all but the two rearmost bolts, loosen them most of the way, then use a jack to make it look like a dump truck. Other people do the same basic thing but loosen all the bolts on the passenger side and remove them on the driver side and jack it up that way. You made it way more difficult than it had to be.

 

[TheBeast]

You mean like this. Still a complete pain in the ass regardless. Next time I do it, dropping the tank.

You must be registered for see images attach

 

[94burbk1500]

I hate dropping the tank, but that's probably because i spilled a ton of gas when i had to do the fuel pump in my suburban, 42 gallon tanks are great, until you have to move them!