In the process of installing a freshly rebuilt 351w (and ECU) out of a 1989 model F150 into a 1987 F150. Of course, a 1987 F150 never came with an EFI 351w since 351 and 460 were still carbureted in 1987 and didn't go EFI til 1988. This truck had the EFI 302, so using the 302 wiring harness. Everything connects up except two items:
#1, a 1987 EFI 302 does not have a canister purge valve, so no provision to connect it to the harness. Will not having it cause a code on the ECU, or can I just leave it off and ignore it?
#2, the 302 has what I think is a knock sensor on the rear, top of the engine block just behind the intake that the harness connected to. 351 does not have this, so pretty sure leaving this connector hanging will not cause an issue with the 351 ECU since it is not looking for it. Thoughts?












I am about a day away from firing it up, so I guess I will find out soon enough if no one has any idea!

 

You will trigger a code when running the KOEO and KOER tests for the missing CANP solenoid. There should not be a Check Engine Light for it.

Since the 5.8L PCM was not designed to use a knock sensor there will be no code without one connected.

 

Thanks for the info! Sounds like I can leave it off then. This truck will most likely never have any of the KOEO or KOER tests run on it unless I am the one doing it. Being an 87 model, it does not have to have that valve to pass inspection in VA (that is where this truck lives).