I need help guys hooked up the gooseneck with the backhoe the other day,and at about 65-70 mph going up hill started loseing fuel psi. Didnt notice any thing coming back with out the backhoe just the trailer til i got into some preety steep hills, then began to loose fuel psi again. while unhooking trailer truck was idleing and shut off , and would not turn on. changed lift pump the next and turned on with out a problem. Today haveing changed the lift pump two days ago got on highway and punched it at 75 mph loseing psi again and not kicking in til hitting 55 mph. Dont no what to do please help!!!!

HOGBOY

 

where is the pressure sensor in the fuel line before the filter after the filter? also have you checked your tank to make sure that you don't have something stopping up the strainer in the tank on the pickup tube?

 

Theres nothing in the fuel tank,and sensor is after the filter. I reseted the pump today and seems to be working preety good just havent goten a chance to hook up the trailer. hope fully that will do it.

Thanks, HOGBOY

 

I had a similar symptom when I replaced my lift pump. A slight kink in the rubber hose between the pump and the filter allowed good PSI until I punched it. My rookie mistake, first one I ever did.

 

is the lift pump and the injection pump the same thing? I keep reading about different pumps on the diesel and I never know which is which.

roger

2004 dodge diesel 4x4 all stock 305 horse

 

bad news guys!! truck did not turn on this morning but is giong for a diagnostic check on monday will keep u all updated.

thanks, HOGBOY

 

Your fuel filter might be clogged.
Sometimes the quick connect on the suction side of the lift pump plumbing will allow air into the pump, you might try putting a drop of oil on the o-ring. A leaky banjo gasket washer will allow air in also.
Get a quart of clean fuel, drain the fuel filter housing, take out the old filter, close the drain valve, fill the fuel filter housing 3/4 full, install your new clean filter(since it's open, just put a new filter in), put a bunch of paper towels under the filter housing to catch the overflow and screw the filter housing top w/new filter down. Clean up your mess and turn the keyswitch just enough to bump the starter a coupla times and start the motor.
Test ride!!!

 

The Lift Pump takes fuel from the fuel tank and presents it to the Injector Pump under pressure after making a pass through the fuel filter.

 

Will do that first thing in the morning. Is there any reason to believe it might be my injection pump?

Thanks, HOGBOY

 

Sometimes a failing injection pump will set off the Check Engine light. You can get the computer checked at most chain type auto parts stores for free.