jmoo1025

02 3/4 ton vin reads cab and chassis got a stock replacement in tank sending unit that doesnt pick up but about 12 gallons of fuel does anyone know why? Fuel gauge works correctly ive been able to put over 33 gallons in before the replacement

Redlinear

What do you mean doesn't pick up?
1) fill it up and truck dies 12 gallons later? (not picking up fuel).
2) Shows on your gauge that you have about 12 gallons, even when full?
3) ????

jmoo1025

Tre truck will die like its out of fuel fuel gauge will read about 5/8 of a tank and I can top it back off with only 12 gallons...
Its like it runs out even though there's 20+ gallons

When it dies I have to put fuel in and crack a line and itll crank right up

RAM2940

Maybe you have a hole in the fuel pick up in the module and it sucking air..

jmoo1025

I wouldn't think so it happened on both new sending units I installed and I got tired of messing with it so I left it and just filled up ever 300 miles but I am needing to replace it now so I was wondering why it is doing what it does

RAM2940

Have you tried a differant lift pump, or do you know what your fuel pressure is running. Just thinking that there are only two items in system that might cause this type problem, and your positive you have a correct and known good fuel module.

whiskers

Did you replace the whole module, or just the sending unit. Big difference. It sounds like a hole in the pick up tube that is sucking air as soon as the fuel level drops a bit. The sending unit portion of the module has nothing to do with the problem if it's registering the proper level.

sweetdreamz

^^ Agreed. Sending unit is just for level, sure sounds like when fuel drops beyond a point it starts sucking in air. Probably does a lot of sputtering before it dies. Replace entire unit and prime system.