I am installing EFI on my 66, and I have a computer from a 93 (5spd), but an AOD out of a 92 5.0l. Do I have to have a AOD EEC? I have heard you can run an AOD EEC with a stick, but not sure about vice versa.
I don't think it will matter. You aren't using the EEC to control the transmission. There is a feedforward that increases idle when you put it in gear...so that feature won't work. I don't think it would work on any EEC, unless you went to an AOD-E and hooked it up properly.
This is just a guess though. Others may no better.
Only real differences on the manual vs. auto EEC-IV controllers from that era are slight changes to fuel and timing curves, plus a strategy that read off the speed sensor to raise the idle slightly on an auto. car when coming to a stop. I've been running an A9L 5-speed computer with the C4 tranny in my Cougar for about 5 years, no issues.
You can run either. I am told that some of the racers actually prefer the AOD computer because of the fuel curves or something. But they will both work. As long as you don't try to run the AODE and make sure you have the right tranny harness.
AOD trannies in the Fox cars weren't controlled by the EEC. Not until the AODE in the 94-up cars ...
Dave, FWIW, I had an 87 LX 5.0 brand new, and one thing I tried when it was around a year old was an auto. computer, because that was supposed to be the hot ticket according to the magazines back in the day. Made absolutely no difference to the e.t. (on my car anyway). :shrug:
The key is in the wiring. Auto cars have a wire going to a computer connector pin that is "negative". A manual car's wiring happens to run positive to that pin. IIRC the effect is that if you have A manual car and harness, plug in what you like. But if you connect a "manual" computer to an automatic car's harness you'll zap the computer.
Also IIRC, the pin involved had to do with one of the oxygen sensors. You can still use a "manual" computer but you have to cut and swap a couple of wires around. Supposed to be no big deal, as long as you catch the situation BEFORE you zap the PCM. Obviously if faced with such a situation you'd want to Google up some harder info. Many folks have done all this stuff already, just usually with later model Mustangs.
Well one guy mentions it there, but thats about it.
I was in pretty good circles with the Fox body swappers, but you've piqued my curious.. I just don't see what it would be by going through the wiring diagrams, nor have I ever encountered any talk of it.
Seriously, i've NEVER heard of this and I've read everything thread I could find on the internet when I gutted my wiring harness and redid it (88 wiring harness..) but now I don't want to risk frying something..
I rather thought I wasn't the only one to have heard of this. During a 5.0 EFi swap about eight years ago someone was kind enough to tip me off that this could be a problem. I verified it (probably at Stangnet) and thanked him for the info. To be safe we went with an auto computer in that project. I never had to get into pinout details at the time, nor did I keep notes. It was a project I was roped into helping with, not something I was ever interested in doing myself. Sorry I don't have more specific info.