1st thing to check is the small ground wire with a round, black connector on it coming out of the negative battery cable terminal. If that is not connected or has a poor connection, you will not have a ground to the computer and the injectors will not fire. This wire goes straight to the computer ground terminal. The check engine light will not come on when you turn the key on if the computer is not getting a ground or not getting power.
If that is good, you can dig deeper:
I power wire feeds all 8 injectors and they are controlled by the computer turning the ground to them on and off. It fires 4 injectors at a time, so there are 2 ground wires and one hot wire going to the main connector on the computer. Start by getting a Ford wiring diagram for the truck and checking continuity between the appropriate 3 pins in the computer connector and the injectors.
The power to the injectors comes from the EEC Power Relay over a Red wire.
The relay is turned on and off by the Ignition switch.
This same Red wire also powers the Computer, other solenoids and the fuel pump relay coil.
Hi Bill thanks for this info ill check this out hope i find the source Where would i find this EEC Power Relay and BuickBrain meentioned getting a wiring diagraphm to check on three wires going to the computer Where could get one of these? or possibly on here? Thanks Tazz from Collins Mo
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.