Lift Pump Going Bad or TPS?
 

What are some of the signs of a Lift Pump goin out? I can be driving down the road and it will spit & spuder. I can hold the pedal to the floor and it stays @ 2k RPM and still cuts out. I don't have a FPG or anything so how will I be able to tell. I would like to know FOR SURE before I spend money I don't have on a new one. Thanks!

Any Codes?

You need to get a fuel pressure gauge on there ASAP.

have you changed your fuel filter

sounds like a lift pump because I had a gauge on mine and did the same thing and i was only pushin like 4 psi...And when I hit 2 grand id push the throttle further and it would blow blue smoke!

Alot of times you can't tell your lift pump is weak and you end up trashing your $1000+ VP44 injection pump. Thats why a fuel pressure gauge is so important on these trucks.

If you dont have a fuel pressure guage - you shouldnt be driving one of these trucks. You must have a big bank account and dont mind occassionally dropping $1200 on a VP-44 hey?

I've got the same problem. The truck will start fine, and run then the fuel pressure will drop until the bd pump on the frame rail kicks in. Checked the lift pump and its getting the voltage and pumps when you first turn the ignition even swapped pumps and i'm still getting the same thing. :argh: any help?? Could this be the TPS sensor?

What is your fuel pressure at cruise and at Wide Open Throttle?

just running the low pressure light, but its fine at WOT, will occasionally flash when idling at a red light, but light goes off when i get back on the fuel.

Dont trust the light - you need a guage.