My motor starts fine will idle fine when its revved it wont come back to ldle just dies . Any help or ides ? 1993 f150 5.8l swapped with 96 5.8l

 

Did you break rule #1 of engine swaps...

1) Do not use any wiring from the donor motor.

 

No i kept old harness .im stumpted on this .

 

Was the 96 an OBDII motor w/ mass air? If so, you would need the donor PCM and the donor harness. Th 93 may still have been a Speed density setup. Depends on what you all kept from the donor motor I guess.

 

It was but i left it off and used old harness . Only thing i had to swap cause the plug was different was the idle control .

 

Did you put the '93 IAC valve on the motor? If not I'd suggest doing that and putting the electrical back to stock.

With all the '93 electrical on the motor you should be good, so was this a good running truck before the engine swap or did it have issues?

Pulling codes is the next step.