Hi guys,
I had the pump replaced in the rear gas tank (both pumps were out, front and rear) by a real lame mechanic. I had to take it back three times before I said f it. The problem is that when I put fuel in the rear tank , as I drive it the gas goes to the front tank. Hence I manually siphon from the front tank back into the rear tank. Could this be the switch F/R tank? Any help would be greatly appreciated.

 

You have a bad fuel module in the front tank.
As it is a 93 I would look close at the Fuel Pump Regulator (FPR) as they were bad from the factory that year. The bad FPR would blow the the non-running fuel pump check valve and cause what you are describing.

 

Keep taking it back to the "real lame" mechanic until he fixes it right... and doesn't charge you anything for it. He did a job for you, and he didn't do it right- he should fix it.

 

It sounds like the he did the work OK on the rear tank the only problem is he was working on the wrong tank. I have heard of Doctors doing the same thing.

 

Thanks for the help. Sorry about the repost (3) my computer is doing some crazy things.

 

Hi Bill,
Thanks for taking the time to help me out. Is it a big deal to replace the Fuel Pump Regulator in the front tank (cost/labor). I am trying to sell the truck so needless to say, do not want to put a lot of money into repairs. But of course would like for everything to work properly when showing it.

Thanks again for the help.

Mark

 

The Fuel Pump Regulator in mounted on the fuel rail on the engine.
The FDM (fuel module with pump) is inside the fuel tank.

 

I had the same problem on my 96 250, replaced both tanks, sending units an pumps
cleared the problem right up

 

The regulator on the rail is easily replaced. There are 3 allen head bolts that holds the regulator to the lines. Pull off any lines and hoses, reverse the steps to install new one.

On my 5.8L F250 it took about 15-20 minutes in a dark parking lot. Great thing is that the bolts when tightened will press the fuel lines onto the regulator.