I just replaced the motor in my 1994 Ford F-150, the motor came out of a f250 but is the same motor as my f150 had in it (5.0 liter). When I got the motor installed and fired it up right off the bat I started having issues. First off when I would put the truck in gear you couldn't feel the truck go into gear and it didn't want to go unless you reved it kinda high. Reverse is almost not even there, it will go but you have to rev really high. Once I got it one the road for a 10 miles the O/D off light started blinking. I'm not sure what could have caused this? Is it possible that this is a computer issue or has something gone bad with the transmission during installation of new motor? Any help would be much appreciated. Thanks

 

If the OD light was flashing, it has set trouble codes. You need to take it to someone who knows how to pull transmission codes on an OBD-1 system and has the equipment to do so.

 

You can also use THIS method to get the codes.

 

With you having to rev the engine high to get it into gear could it possibly be a TPS?

 

No, the OD Off light won't flash if it's the TPS.