Automatic ECU vs. Stick ECU
 

I installed a complete 5.0 motor out of a 1991 Mustang into my 1969 early Bronco using the Ford Motor Sports conversion harness. I had heard that you could use an automatic ECU in a stick shift vehicle, but that you couldn't use a stick shift computer in an automatic application. Anyway, my engine came out of an automatic Mustang and my Bronco is a stick shift. Everything works perfectly, except that, when you let off the throttle to shift, the revs don't come down as soon as you lift off. Basically, if you rev it, there's a two to three second delay before the revs drop to idle. Also, it wants to maintain idle revs no matter if you're in first gear or high gear. In other words, if you want to slow down in high gear, it wants to maintains about 600 rpms, whereas, in a normal stick shift car, you can virtually slow down to a stall speed. Bottom line, it just isn't right. Do you think this condition is caused by the automatic ECU in my stick shift application, or do you think its something else? I don't know what else it could be. I wanted to ask before trying to find someone with a 5 speed to see if they'd let me try their ECU (no easy task in itself).

Mike Mileski
Tucson, AZ

Mike: From what I have read you are correct.

5 speed computer in a AOD = BAD
AOD computer in a 5 speed = GOOD

I am sorry I cannot help answer your question, I just wanted to confirm that you are correct about the computers.

Ian

Mike what you said about the delay in the throttle is correct. You can use a auto computer in a stick car but it is highly frowned upon to to the opposite. I swapped a t-5 into my Stock auto car and never touched the computer. It worked well. Should be the same in a truck.

Brad