zdaily said:
I have a 66 Bronco and am installing a 1993 5.0 HO motor. I have everything, wiring harness, etc. Motor is installed and we're well on our way, hopefully be done this weekend. I have a quick (hopefully) wiring question:
- I'm using the stock wiring harness that came with the motor and I want to completely remove everything I don't need?
- Is this as easy as removing the wires all the way into the ecu and sensors?
- What's everybody else doing?
- Does anyone have a list of what you must keep in order for the system to run well?
The first thing you want to do is check your State SMOG requirements for an engine transplant. If you are in California you are required to have all the SMOG stuff that came with the '93 engine. You would not have a problem if the state didn't know about it but if you sold the vehicle in state the buyer would not be able to register it until all the SMOG stuff were hung on & working to '93 specs.
My base engine is a 1970 302 which does not require SMOG testing in California. That out of the way:
I kept the valve cover to throttle body tube and the PCV system, and lost the rest. The older engine doesn't have the ports to connect the EGR valve. With the newer engine you might want to keep the EGR valve since it only works during highway cruise conditions and may actually help highway fuel mileage a little. If you eliminate the EGR assembly you can bolt the throttle body directly to the upper intake manifold. The idle air bypass valve likely will interfere with the upper manifold, requiring you to either dig up a spacer or grind an eyelash into the manifold where the valve contacts it.
If you eliminate the EGR valve you will need to weld up a water tube nipple on the metal tube that runs heater coolant past the manifold and do the same with a vacuum port on the manifold attached to the underside of the upper manifold.
Ron Morris Performance offers a EGR eliminator kit that includes a plate to attach the throttle cable linkage. This is the one you want if you choose to eliminate the EGR body. Otherwise you will need to leave the EGR body in place. Oh & Ron Morris is a source for Ford EFI fuel lines & fittings.
The external to the engine SMOG stuff is run by relays. I replaced each with a load resistor so that the computer would think the relays are there and not generate an error code and turn on the check engine light. I left the wires to the unused relays in place and cut off the connectors soldering in resistors in their place. IF you live or sell your vehicle with the '93 engine into a state requiring SMOG tests best to keep the connectors in place and fabricate mating plugs that have the resistors. Otherwise you will be in a mess come time to sell the vehicle where SMOG is required on the newer engine.
I checked my harness against what I thought to be the closest schematic modifying a master copy with any differences I found, including wire color. I picked out any wires I didn't need for the EFI, then laid the Mustang harness into place. I merged the EFI harness with my existing harness, eliminating the Duraspark wiring and rewiring most of the other engine bay wires to match the Mustang harness then buttoned it all up as a new single harness.
Anyway thats how I added a 1991 Mustang EFI system onto a 1970 engine previously equipped with carb & Duraspark ignition.
Good luck with your project!
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