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who here has made there car with a 302 or 351 into a fuel injection with a new harness and computer ?
I have not done this on a 65/73 but have converted several early Fox Mustangs to EFI/EEC-IV. I have made my own harnesses for these conversion. There are several members here that have converted their early Mustangs to EFI based on the 86-93 EEC-IV as well as using aftermarket throttle body EFI setups.

Paul
 

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Discussion Starter #3
I have not done this on a 65/73 but have converted several early Fox Mustangs to EFI/EEC-IV. I have made my own harnesses for these conversion. There are several members here that have converted their early Mustangs to EFI based on the 86-93 EEC-IV as well as using aftermarket throttle body EFI setups.

Paul
was it a big job for he harnesse ?
 

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who here has made there car with a 302 or 351 into a fuel injection with a new harness and computer ?
When you say new harness and computer, are you referring to a new aftermarket EFI harness or a rebuilt original EFI harness?

I used a new Ron Francis cobra 75 harness. As for the ECU, to my knowledge all will be used (rebuilt) from a 5.0 donor, which is what I have. Your options are A9L for 5speed and A9P for autos, plus a few other but I am not familiar with those. A9L can also be used for autos but A9P can NOT be used for 5speed. Ron Francis wiring allows you select version of computer you are using during installation.

I hope this helps.
 

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I used a 1986 Mustang 5.0 harness (free to me) that I converted from speed density to mass airflow. Computer is an A9L, but my engine modifications (heads/cam/intake/larger induction system) don't work with the computer in stock form so I added a TwEECer to the computer so I could tune it. Works great!


Converting and stripping a harness can be a bit intimidating if you aren't comfortable working with wiring. Not a problem for me since I understand and work with complex wiring systems as part of my everyday job.
 

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was it a big job for he harnesse ?
For some of the early Fox cars Ive converted to EFI I modified existing Ford factory harnesses and for some I made my own - wired from scratch - harnesses. This was 20 years ago. If you are planning on doing this I would recommend you start with a 92-1/2 - 93 harness that has the fuel pump circuit/ relay integrated into it. The older harnesses can be modified but are more work. Alot has to do with you skill level, etc. I spent a good part of my career in the electronics and electronic interconnect industry so I am very familiar with wiring harnesses, connectors, etc. If you are planning on using the EEC-IV setup one thing I cannot emphasis enough is to fully familiarize yourself with the workings of the system and there are many good references online and in print form.

paul
 

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I used a 93 mustang harness I got off ebay and the probst manual printed off summit racings site to put a fuelie 5.0 in my 47 willys jeep. Just pay very close attention to the wiring for things like the coil so it see's keyed hot and cranking hot....... ask me how I know! also, dont use a small LED light for the check engine light, the PCM doesnt like that, use a regular bulb.

Make sure the o2 sensor harness is for the PCM you have (I.E. Auto harness for auto PCM, manual for manual) as there is a jumper wire that is different between the two and will burn out part of the circuit board in the pcm if the wrong harness is used.

Lastly, head on over to pirate4x4 (not sure if mentioning a different forum is allowed, if its not feel free to delete this part) there is a section in the jeep hardcore subforum all about 5.0 swaps. Its called TOTW ford 302 engine swaps.
 

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I did one in my Ranger 5.0, had both Mustang and Ranger EVTM's (electrical diagram manuals) and it took me about 2 months working a couple hours a day to finish it. I almost quit several times. Would NEVER do it again! I am considering using that motor and the GT40 EFI in my 69 Cougar, but I will pay through the nose for a swap harness this time. One of the biggest problems I had was integrating it with the existing Ranger harness and relays. So far I think Ron Francis' Cobra harness will work for me.
 

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I went the easy route on my street rod and bought a RJM wiring harness. I just had to lay it in, plug in the sensors, hook up ground and power wire on my street rod. The reason I really wanted this harness is that all the wires are labeled every few inches.
 
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