i posted in the wrong section so i'm reposting my problem. i just installed the fass 150 gph lift pump and it keeps throwing a 0090 code which is fuel pump amperage too low. anyone know why this would happen? as well the truck runs out of fuel if you turn the pump off. i thought this was a flw through design. any thoughts would be welcome.

Have you checked what the delivery PSI is yet? Most gear and sliding vane pumps do not like to flow through when the gears are not turning.

i posted in the wrong section so i'm reposting my problem. i just installed the fass 150 gph lift pump and it keeps throwing a 0090 code which is fuel pump amperage too low. anyone know why this would happen? as well the truck runs out of fuel if you turn the pump off. i thought this was a flw through design. any thoughts would be welcome.

Any chance you have it plumbed incorrectly?

i checked it about 4 times but i'm going to go through it once more. when i crack the bleed screw under hood and turn the pump on it pushes fuel out. could it possilbly do that if the plumbing was reversed? just went out and checked fitting T is coming from my tank, fitting E is going to my stock pump, fitting R is my return tied into filler spout. could someone tell me if this is correct. part of the instructions are hard to read. thanks

plumbing is correct. i have 8 psi right in front of the stock pump. my rail pressure however is maxed out at idle i'm wondering if my pressure regulator went south. any thoughts?

remove the pump from the equation (bypass it) and see how the truck runs.

i bypassed the fass and the problem is still there. throws code 90 which is rail pressure to high. hooked the scanner on at the dealer and it still is at max pressure. i am going to put in a new regulator and see what happens.

turns out it was the regulator. put in a new one and everything worked fine. drove down the highway with the dealers scan tool hooked up and the fass does not raise rail pressure.

Did the regulator fail as a result of something during the Fass install? Or just a coincidence? If so it would be a first.

it seems a little coincidental but i don't know what i could have done to cause it. maybe it was weak already.