1972 f100 efi 5.0 swap. please help

[mustangmike_1981]

i have just swapped an efi 5.0 HO from an 86 mustang gt into my 72 f100 shortbed. i have everything hooked up and it is very hard to start. once started, it doesnt idle very good. when it was in the mustang, it started right up and everything ran good. any ideas on what might be wrong? i have double checked all the connections and everything is plugged in. any help would be great. thanks.

[Soaring]

It is difficult to address your problem with the small amount of information you have given us.  Usually if a motor is hard to start, it isn't getting hot enough spark or the fuel is not flowing fast enough.  So, with that in mind, I would check the spark and the fuel pressure. 

[rmodel65]

kinda sounds like the fuel pump is bleeding off the fuel pressure is maybe try tuning the key back and forth a few times to build adequate line pressure. as for it not idling have you tried cleaning the iac (idle air control motor) its mounted on the side of the throttle body