This weekend I dropped the rear fuel tank because it bad gas in it. I cleaned the tank and installed a working fuel pump. When I select the rear tank the fuel pump cycles and shuts off but will not send any fuel to the engine. Did I miss something? Do I need to purge the system to get fuel to the fuel rail? Truck runs fine on the front tank.

 

I tried bleeding the fuel system with the rear tank activated but the fuel pump will not turn back on after the initial ignition key on cycle.

I'm stumped. Does anyone have any ideas?

 

The same circuit runs both fuel pumps so it sounds like the rear pump is not doing any pumping.
The check the pump select the rear tank on the dash and ground pin #6 or short it to pin #2 of the Self-Test plug on the drivers fender and turn on the key without starting it. The selected pump should run all the time the key is on.


/

 

Thanks, I will give that a try tonight.

 

I hunkered the test plug and the pump stayed running but with no output at the test port at the fuel rail. I quess I either have a blockage somewhere before the fuel filter or the pump is bad.

 

The previous post should have read jumpered not hunkered. Gotta love these phones changing your words.

 

At least you know the wiring is OK.

My vote is for a bad pump.



/

 

I believe you are correct. The tank was a mess when I dropped it. It had sat for at least 4 years with 12 gallons of gas that had turned to turpentine. I had to work pretty hard to get it cleaned out. Even took a pressure washer to the inside to get all the junk broken loose. I don't need the back tank but I like everything to work on my vehicles so I spend the time and money to reach that goal.

Thanks for the help.

 

You should be able to take the pump back and get another one for no charge.
I did that three times in a row at NAPA and then they gave me another brand pump and that one worked fine.