I recently purchased a 94 F-250. The prior owners let it run down some and im fixing it up as I can afford to - a little at a time. They only used the front fuel tank. I cleaned out the back one and replaced the fuel pump, float and tank filter. I put fresh fuel in the back one. When I hooked it all back up, the front tank is now pumping fuel only to the back one and the engine is not getting fuel. I also replaced the switch in the dash for changing fuel tanks. What did I do wrong and how do I fix it?

 

I used to work on these. Let me do a little checking and maybe I can suggest a possible cause and correction. .......... hanky

 

I do have a 1994 Ford (OEM) Service Manual and as of this time can't find what I am looking for. I did find a schematic for the system and it did show an electric switching valve under the vehicle attached to the frame. At this time I would suggest that you find this valve by tracing the fuel supply lines from each tank. They have to go to the switching valve before the fuel can be directed to the engine. I would suspect this valve was defective and thats why the former owner only used the front tank, or couldn't afford to fill both tanks. Did you recheck the wiring connections at the switch in the vehicle? One or two wires could be in the wrong place unless it is the plug in type.

Let me know what you find. Thanks, hanky

 

i have a 429 that had a motorcraft carb on it when i bought it. how do you tell which one it is. where are the numbers?

 

A Motorcraft carb has its name on it. This takes me back some. I believe you have two floats and two metering blocks. The numbers are on the main casting because you could get different metering blocks and float bowls if you had to replace them. I also believe you could adjust the float levels while the vehicle was running. There was a connecting tube between the two systems to equalize the fuel available. I will try to get the info you requested. hanky