My friend swapped a 1992 4.9 into a 1988 f-250 that used to have a 5.0 in it. It didn't run when he was done, so he gave it too me. He used the 1992 computer and the 1989 distributor out of a different truck. Now the bad part. The fuel pump doesn't work. Any connection? Anything else that I should check or do?

 

It's likely the computers are wired differently.. pretty sure by '92 Ford had moved the TFI module to the fender off the distributor.. and the module may be different as well. You should have enough wires in the 5.0 harness to make it work, but you'll have to dig up pinouts for both systems and swap some pins in the EEC connector. Maybe somebody else will stop by with links to these diagrams....

 

Whatever he dug up was under the dash. Possibly not even the computer?

 

www.fordfuelinjection.com might have wiring info for this setup. If you can get the proper year efi harness for the 300-6 and computer from a yard that should help. the wiring from an f150 may also work.

also check the inertia switch under the dash if it trips the pumps wont run at all

 

That inertia switch is the llikely culprit, but check to see if you have voltage to the pump, and that the fuse isn't blown. When the trucks sit for a long time, such as during a engine swap, the fuel pumps often go out from lack of use.

 

fuel pump relay (little green cube) on the firewall, second black wire to the negative battery post, inertia switch, and/or one of these wires pulled apart along the way somewhere will cause the fuel pump to not kick on when turning the key. Also the fuse, Like Matts72 said.

 

Where is the fuel pump fuse? It doesn't seem to be listed in the fuse panel. The inertia switch wasn't tripped, and the relay is fine. The puzzler, the fuel pump worked before the swap.

 

have you checked the connectors on the fuel pump itself. have you pulled codes from the computer?

 

Problem solved. I examined the grounds with an ohmmeter, and found that 4 were bad, and the other 4 were visually disconnected. I moved the truck from a snowbank to a garage, so it is a lot easier to work on.