94 GMC 350TBI stall

[Kenoverbey]

My truck has an issue of stalling taking off or accelerating hard unless it's full of fuel. If it get below 3/4 tank it will stall and start right up. I just realized today after filling it up cured it it. The guy I bought it from told me about it and said he replaced the pump. I'm I correct in thinking the fuel pump assy is defective? A split attachment hose or something?? Anyone else had this issue?

 

[Sean Buick 76]

Yes 95% chance you need a new fuel pump. The advised test is hook up a fuel pressure gauge in line to confirm poor fuel pressure.

 

[Sean Buick 76]

It could also be the $15 fuel pressure regulator in the TBI . Found that out after paying $590 for an un needed fuel pump. Was living in an apartment no place to work on things, payed dearly.

 

[Rock Hard Concrete]

Usually, running better with a full tank of fuel means the pump is weak. When the tank is full, gravity will help out a failing pump.

The regulator could be bad, but that should be bad all the time not just when below 3/4.

 

[PlayingWithTBI]

Maybe you have a hole in the suction tube, when your level goes down it sucks air. Just a thought...

 

[monsterwake]

I just started having this issue. I put a new pump in the first week of November. I only replaced it because the sender didn't work. Now that it is working, the guage only works from full to about half a tank but that is better than nothing. The new pump is much louder than the old pump. I never have to get more than 15 or 16 gallons of gas when I fill up. Like I said, it just started this week. I only experience it on excelleration. I can drive 80 on the interstate with no issue. Starts just fine too.

 

[monsterwake]

Fuel pressure was good. Replaced the fuel filter and dumpeda bunch of rust out of the old one. I had just put that one in back in November. But, I think my issue was actually my gas cap. I went to add fuel and when I removed the cap, the tank released a lot of pressure.