Need help, rear fuel tank is not working

[Lonesome7.3]

1996 Ford f250 with a 351W gasser. Less than a year ago the rear in take fuel pump went out, so I replaced it with a new one. It worked great for a while then a few months ago it stopped working again. The truck was down for a little while for a new crate engine and some minor body work. That work included pulling the bed off the frame. Some time after that it stopped working again. Yesterday I pulled the bed and checked all made sure it was plugged in. I then went ahead and installed another brand new in tank fuel pump. And, it still no work. The switch appears to work fine. The truck will run on the front tank but when I hit the switch it sputters and dies. What should I look for? Does the rear pump have a separate relay or fuse? What else could cause this problem? I am on a tight dead line this truck has to be on the road heading south in a day.

 

[gandalf]

I'm far from being an expert on these things, but I'll offer some suggestions/WAGS at possibilities. There are many assumptions made.

The first assumption is that the rear tank has sufficient fuel. Sorry, but we have to check that.

I'll assume that when you had the bed off you checked that power was getting to the pump. Right? That would tend to rule out an electrical problem. So the question: Is power getting to the pump? Does the pump do anything when you tell it to pump fuel (pump, hum, vibrate, make noise)? Have you checked the switch at the dash?

The other possibility is that there is a blockage in the line. Even the showerhead could be blocked. You might want to pull the pump to check that. Disconnect the fuel line between the tank and the fuel selector valve, and try blowing through it, from the valve end. Be sure the line is free and clear. BTW, that fuel line clips on these trucks are Dorman part #800-015.

The next culprit is the fuel selector valve. It may be stuck or otherwise not working. It too is electric. Pull the connector on that and be sure it is getting power. No power = no switching tanks. You may even have crap stuck in the valve blocking it. Try to be sure it's clear. Disconnect the supply line from the rear tank and replace it with a length of 3/8th clear line (it slips right over the nipple on the selector valve) to another source, a jerrycan of diesel. See whether it moves any fuel.

The system forward of the fuel selector valve is known good since the engine will run on the front tank.

Hope this helps in some way. As I said at the beginning, I'm no expert, but just throwing out ideas.

 

[Lonesome7.3]

Some good points there. I am leaning towards a blockage. However, now that you mention it I di not remember hearing it hum or click on.

 

[MUDKICKR]

there is no selector valve on the 92 up gas trucks, but other then that, thats about all it could be.

 

[Lonesome7.3]

That is correct, there is not valve on our gasser. I did not realize only the Strokes came with them on that body style until I crawled around both.