A9P or A9L ECU for 1986 Lincoln Town Car HO swap?

[JJ10x10]

Good morning gentlemen,

I am trying to research and find out which ECU is required for the H/O swap. I have heard that if you want MAF that an A9P computer is recommended. However I have found an A9L locally for a reasonable price. Will the A9L be a direct swap in, or will I have to make wiring changes? (Besides the changes that are necessary due to MAF conversion.) If this is not feasible what would be the best speed density ECM to go with? I have heard that Rock Auto will provide ECUs but I am unsure of their fitment. Their part numbers are much different. If someone could clear this up for me it would be greatly appreciated.

[sly]

A9L is for a manual trans. A9P, A9M, A9T are for automatics. A9L may bog in drive with an automatic without adjustments.

[JJ10x10]

Thank you Sly. I am wondering what wiring changes need to be made, or is it just plug and play with MAF converison?

[JJ10x10]

Also, can you get the A9P on rockauto? Does anyone know?

[JJ10x10]

Bump?

[sly]

I don't think A9P is available except via junk yards and personal sales (ebay and the like). All of the listings on parts places are for rebuilding the one you already have by sending it in to them.

Also, A9M seems to be less desireable because folks don't know it's pretty much the same as an A9P but wasn't used on the GT, but the LX V8. Pretty much the same thing. A9T was used on the police pursuit mustangs. And yes, with a cam swap (HO engine swap), A9P/M/T are plug and play after adding the MAF wires.

[gadget73]

There is also something about the neutral switch wiring between the auto and manual that I do not recall. Switched one way it won't' read codes, the other way something in the ECM is damaged. One switches ground open and closed and the other switches +12v I think. The fine points are probably out there and I think its possible to use a relay to work around it but its not something I ever dove into.

You do want to add VSS wiring to the ECM though. It works without it, but it tries to open the EGR valve just off-idle and creates a bog. I fought with that for years on mine before finally adding the connections in a fit of 'fuck it, do something' and the problem magically went away. 86 from the factory has no VSS connection.

[JJ10x10]

Okay so, that leaves me with this question. Those who ordered ECU's from Rock Auto: how did you know you were getting the right P/N? If I were to order an ECU for a 1988 Mustang (speed density) would that work for me?

[Tiggie]

If going speed density, you can use any 87/88 Mustang with the 5.0 automatic federal emissions. You can also use the Lincoln Mark VII but be sure you get one for an HO, the 92 model year is a guarantee for that.

[gadget73]

Anything 88+ for a Mark VII is HO.

still probably need the VSS wiring, and if you plan to do much beyond a stock HO they dont' really work super well.