I have been having trouble with my rear fuel tank after a while it starts chugging like it’s not getting fuel to the engine and the engine will shut off as if it’s starving for fuel. I will cycle from the rear tank with the fuel switch to the front position and use the front tank which I don’t have any issues for the most part I have replaced the fuel pump the tank is clean what could be going on.

also if I switch back to the rear tank it fixes it for about a minute or two then goes back into the same routine

Help!

Don Donelson

 

It sounds to me like the rear pump is not working, or there is a block in the line. Fuses good? Wires all connected? Have you done a test on the fuel pump in the back tank?

Usually, once you switch to a working pump, the lines and filter are filled with fuel. Switch back to the empty tank or bad pump/tank/supply the minute or so of running is just burning up the fuel in the line.
Find a point in your rear fuel line that you can disconnect, switch the tank to the rear tank and see if it is pumping fuel out. My bet is that it isn't.

 

The Ford dealership Put a brand new fuel pump in two day’s ago.

so am I opinion it cannot be the fuel pump itself. The tank is relatively new

dealership also made sure It had no crude in the tank

 

They put the new fuel pump in, but what kind of tests did they run and for how long? I'm not sure I understand how they could put a new pump in, do any kind of testing with it and you almost instantly have the same problems with it. With my 87 460, empty - no weight - I could go 1.5 miles on average at 55 mph before I lost power. (Deliberately switching from a full tank to empty tank just to see the effect.)

There only 3 other possibilities that comes to mind right off the top of my head all things, such as runs fine on front tank, considered.
That would be a plugged, pinched fuel line....that the valve is moving just enough to cut off fuel from the front tank but not far enough to get fuel from the back tank.....The fuel pump is not getting power for whatever reason, be it a fuse a wire disconnected, a relay, electrical internal to the pump itself.

So, once again I would have to talk to your Ford dealer and see what kind of testing they did when they replaced the fuel pump that satisfied them your problem had been fixed.

Ford parts have a 2 year warranty on them and I think that would apply to the fuel pump. You can disconnect a line and do a fuel flow test to confirm, but I would be having a chat with the Ford shop.

Ford just put a brand new Turbo on my 2011 and they said it failed their testing so they didn't even make it out of the repair stall with it. They had to turn around and pull it right back off and then wait for the replacement to get here. Things happen.

 

I’ll check on the fuel pump type.

Here are some known facts :
-the front tank does exhibit some same issues as the rear but on a scale of 1 to 10 it’s a 2, very little
-the rear tank does run from the get go but varies in duration before trouble.last night I drove with a full rear tank from Miami to home no issues.
-so the new rear fuel pump I believe is good
-the rear tank was checked and is clean from debris
-the master tech checked the wiring and found no obvious issues

I believe these issues have to be a ground / voltage issue

Can someone guide me to someone who has done a trouble shoot and repair. To help guide me to the correct wirings

 

I have the truck at a different repair facility and they can’t duplicate the rear tanks failing so the tech suggest replacing the fuse link for the rear tank
I also asked him to check the ground wires

 

I took my truck to a different mechanic they couldn’t get it to imitate the problem that I’m having, So they went ahead and replace the fuse link as a maybe to the rear tank.

Is there any reason why I can’t cut the power lead for the rear tank that goes into the switch on the dash and rewire the hot lead and ground to wires I’m talking about and just rewire it and be done with it.

 

I have replaced the fuel switch on the dash and will keep everyone posted

 

This current recent visit I had them tie into the ground cable as close to the tank as possible and ground it to the chassis to take away the ground issue causing the problem.

I have replaced the fuel switch backwards forwards on the dash, I replace the fuse link for that rear tank, replace the fuel pump, and the tank is relatively new and cleaned out.

So far I’m having no issues with the tank by re-grounding it to the chassis. I’ll keep my fingers crossed and keep everybody posted.

I suspect this will work but if it doesn’t I’m going to rewire the hot ground into the switch on the dash and coming out of the switch to the fuel pump and go that route if needed

 

so I Really thought I had the issue resolved. With 3/4 of the rear tank gone no issues in the engine ran better than it ever has on the rear tank. However the problem did raise its ugly head at about a quarter full of gas and then same situation happened again.

The engine starving for gas and about to stall, I turned the switch of the fuel tank to the front and it immediately started running perfectly switched it to the rear again and it ran fine which is the way it normally works when the problem arises.

The only thing that I have not done, is fully rewire the hot and ground wires to the fuel pump for the rear, starting from a new positive lead wire from the battery to the front back switch on the dash and then on the other side of the front back switch leading a wire to the fuel pump itself obviously using a fuse link for safety

 

First thanks for everybody’s help think I got the problem solved. Took it to a new shop, they should be shop number three, and they diagnose that they complete assembly for the fuel pump that goes in the tank look like hell. Not the new pump itself that was first put in by the Ford store but the assembly itself.

They replaced it with a completely new full assembly not just fuel pump pop it in and it worked fine no issues.

Question that I do have is this truck has been getting about 8.89, 9 miles to the gallon around town, that sound right?

Know that during this driving. The O2 sensor was out of whack and I was getting a check engine light. This is now fixed with a new O2 sensor and no more check engine light.

What can I expect with casual driving around town and on the highway with my 5.8 motor in 353 355 gears

 

Drove 4 hrs with both tanks topped off and got 16.3 mpg

 

I have the same problem with my 92 f250 but it dies INSTANTLY when i switch from front to rear...make no effort to run whatsoever until i switch back to front.

 

I had a 92 with the 300 - 6cyl and a 96 - 5.8. Both with dual tanks and both with the same problem you are describing. Both turned out to be in the switching valve for front to rear tank. The 96 we weren’t able to correct the problem and just stopped using the rear tank