I have a 95 XL with dual tanks. When using the rear tank, return fuel will go to the front tank. This causes an overfill situation if the front tank is already full. After some research I have determined that the fuel delivery module (FDM) is broken. In the FDM there is a shuttle selector valve. That valve is not opening and closing as it should and I have to replace the FDM in order to get it to work correctly. My question is, where is the FDM? Is it in the tank or can I get to it externally. I'm thinking it is probably part of the fuel pump and is in the tank. Is it possible it is external and I can get to it without dropping the tank? Someone told me it was along the inside part of the frame, but wasn't specific as to where. I didn't see anything. Of course I don't really know what it looks like either. I'm thinking that was on earlier models. Or another possibilty is that I ma a victom of poorly written service manuals and the FDM is just another name for the fuel pump, and in that case it's in the tank. Post pics if possible. HELP!

Jim

 

Jim,

I have a 96 F-150 XL Electrical and Vacuum Troubleshooting Manual and there is no FDM listed anywhere. I might suggest you go on eBay and get the exact factory manual for your vehicle. That's what I had to do to have any hopes of fixing a complex no start condition on my truck.

E. J.

 

this may give you somewhere to look,on the earlier models the tank switch over unit[which is often the culprit for this problem]was situated on the inside of the drivers side chassis rail near the front tank,its got about 4 fuel lines on either side,and the check valves were inside this unit.this setup only applied to the 5.0 tho.Got no pics,sorry cant help you there.

 

The switching valve is on the frame rail on the drivers side,if you have a fuel transfer problem that is most likely your problem.The only thing thats in the tank is fuel pump & sending unit.You should not have to drop the tank to replace the switching valve.

 

That's incorrect. The switch over valve was moved to the tank in either 94 or 95. Mine is a 95. They incorporated the FDM and fuel pump all in one part. There may be a recall on this FDM. I am going to the dealer to check that out today. I will update with results.

Jim

 

The only recall I can see on http://www-odi.nhtsa.dot.gov/recalls/results.cfm is seats and cruise control.

 

Well there were no recalls. Just a service bulletin years ago. Any work would have only been covered under the original warranty. Do you think a 95 is still under warranty? LOL.

Jim

 

I'm curious what you found on this subject. I recently purchased my first ford and am having the same problem described above. I work at a parts house and after my own research i discovered an autozone part #FSV2. It is listed as a "universal fuel tank selector valve" for later model trucks that use return lines and an FSV1 is the appropriate piece for a non return system. However a friend of mine said that, as stated above, in my 94 F-150 the valves had been incorporated into the pump assemblies.

 

You are correct. For my year (95) eveything is incorporated together. It's called a fuel delivery module (FDM). It is about $140 at Advance auto. It contains the selector valve, fuel pump and float mechanism for the guage. The front FDM's selector valve is stuck open, so when I use the rear tank the return fuel still goes to the front tank. You can't replace just the selector valve as on previous years. (not sure what year the FDM was first implemented)You have to replace the whole FDM. This requires dropping the tank or removing the bed. I am told removing the bed is easier. So for now I am dealing with it as it causes no problems. I just always use the front tank.

Jim