I have a 1994 f150 5.0 4x4 with a E4OD trans. I replaced the MLP/TR sensor with a 1995 sensor for an E4OD. Truck starts but idles and runs extremely rough. Wonder do I need to maybe reflash the ecu or what?

 

There is no ecu "flashing" on this vintage Ford. Replacing the TR sensor has no bearing on the engine performance or the idle quality.

 

What do you think it might be? It'll start up fine about the first three times but idle extremely rough enough to shake the truck side to side. And then eventually won't start up it'll just crank

 

How old are the plugs, wires, cap & rotor?

Is the Check Engine Light On? Regardless if it is or not have you ran the KOEO tests and CM code display?

When it will not start have you checked for spark? Same for fuel pressure?

 

Yeah you need to pull the codes and check fuel pressure, that will point you in the right direction to solve the problem.