Replaced original fuel pum in Aug 2015. Truck wouldn't start last week. Couldn't here fuel pump running or engaging with the key on tested pressure at the rail and got 10-20 pounds. Figured it was dead. Went through a nightmare getting a replacement pump from parts supplier s they said it was on backorder. Finally got a pump.

installed the pump, the truck wont start. Tested the fuel pressure gauge shows 39 pounds, which is 1 pound below running pressure and 10 pounds short of starting pressures.

Pulled the fuel pump relay and jumped the connections and got 39 lbs again. I am assuming the wringing is working.

is there anything I am missing? Is this another New part failure, that us old bastards love to complain about?

Regards,

oldfatandtired

 

Assumptions are dangerous .... Bad wiring can cause voltage drop which makes the pump not reach full pressure. Try rigging up some temporary wiring providing power to the pump from the battery or even just a battery sitting next to the truck. Did you get the whole fuel pump assembly with the pressure regulator ? So many parts nowadays are junk so that is certainly a possibility.

 

39 pounds is correct for your truck, starting, or running.

Are you getting spark? Injector pulse?

 

I have 12 volts at the plug to the fuel pump. Ran a 12 volt jumper wire from the battery and got 39 pounds.

 

I can start the engine on ether and it runs.