1997 superduty dump truck with 7.3 turbo, auto, 186K miles.

The truck sits a lot. Starts well, no smoke, but the last few times out the truck has been very weak.
Seems like a fuel issue. When warm I'm getting fuel pressure of 10 psi at idle and 18 psi at 2000 rpm which I know it too low.

I have pulled the fuel pickups from both tanks and replaced the in tank screens (no in-tank filters in my 97) and cleaned everything. The tanks and pickups were not really dirty.

How do I tell if the problem is the fuel pump or the regulator? The pressure drops to 0 immediately when turned off. Does that mean there is a regulator leak?

 

If its not leaking externally anywhere then my bet is on the pump. The regulator is just a spring and valve/seat. Not that the regulator can't go bad but its much more likely a pump issue.

 

^^I agree with Aaron^^

 

get a new pump and FPR spring then you should be good for many miles


20 is too low and you are starving for fuel


yes it will drop pressure fast, there is a hole behind the FPR screen in the bowl that releases the pressure fast.


FPR Spring and other info in this thread
https://www.ford-trucks.com/forums/1...sel-truck.html