3500 dually 4x4 no mods 185,000 fuel pressure drops to 0 at wide open throttle boost only goes to 20psi and how many fuel pumps does this truck have can only find the one mechanical at parts stores but keep hearing about a lift pump ?

 

It just has one fuel pump.
There is a small lift pump below the fuel pump on the lt. side of the motor. The lift pump helps supply the fuel to the fuel pump. And if it's going out than your fuel pump is starving of fuel.

 

ok thanks thats what i was thinking

 

Id check the fuel overflow valve before I wrote off that lift pump.