trying a different PCM

[chris-CMC#35]

I found a good price on an A9L computer for my '94 GT, and am going to give it a try. I know I need to swap/change some pins to get it to talk to my SN95. I've been through quite a few forums, and found variations of the same comment: "you need to swap some pins" but without specifics.

Can anyone suggest a source for details?

thanks,
chris

[Mike Bell]

Chris,

I understand it can be difficult from what I've read. You need a pinout diagram for the A9L and for the SN95, a BAP (Barometric Absolute Pressure?) sensor, and a fan controller. I have the SN95 one on another computer at work but can email to you Monday.

Pro-M used to make a harness for this specific swap but they went out of business, it was called a PIH (Performance Improvement Harness) and I understand it was expensive. Not much demand for it nowadays with programmable chips being so cheap I guess. Hope this helps.

Here's a wiring diagram for 88-91 EEC I found on the web:

http://www.veryuseful.com/mustang/te...1eecPinout.gif

[Garbage]

The easiest way to convert your '94 to the old computer is with a Painless Wiring Harness. There are too many variables to try and rig your current harness to work. The distributor, MAF, TB, and a couple of sensors need to be swapped out. The benefit is a lose of 150-200lbs of junk that a race car does not need.

[chris-CMC#35]

uh oh, sounds like I may be getting in over my head - which doesn't take much.

good feedback guys, thank you very much.

-chris

[Mike Bell]

Chris,

I found the place that makes them now:

http://www.massairsystems.com/electronics.htm

E-PIH2 comes with the sensors, all you need to do is add an A9L and follow the pin change instructions. $328 seems steep but since you can't do chips in CMC it might be a help?

[marshall_mosty]

There isn't 200 lbs of wiring in the entire car!! A bumper to bumper harness weighs 50 lbs... All the other switches etc. won't be more than 20 lbs.

Total weight savings for a "Painless" swap will be less than 50 lbs... guaranteed.

[chris-CMC#35]

Mike,
Many thanks. This proves - once again - that I'm an amateur when it comes to finding things on the 'net.

Todd/Adam/Ryan,
I know that using an A9L is permitted under CMC rules, but just to be safe: is it okay to also use this harness adapter, so that my car can actually talk to the A9L?

thanks,
chris

[Rob Liebbe]

Chris,

I thought '95 cars were rated pretty close to the older cars for hp and torque. I know that you have thought a lot about this, but are you sure there is nothing wrong or different about your car. Did you ever check the compression? Did you ever try another '95 computer? What dyno numbers did you ever end up with after the new exhaust?

I'd just hate to see you spend money on this and it not be the problem. I hope I'm not out of line and haven't missed any threads about your progress, but something still seems weird.

[chris-CMC#35]

Rob - not at all out of line, I really appreciate the thinking.

re: compression, I checked it, and all was well.

After installing the new exhaust, HP was dyno'd at 197.

I didn't try a different '94 computer. But given the expense/effort associated with installing an A9L, I'm going to find one, install it, then re-dyno. I know I can sell the A9L.

-chris

[Mike Bell]

Chris,

Did you get an official answer on the legality of this harness? I'm a fellow SN95 owner, might be interested. Let me know will ya?

Rob, from all my internet reading, the SN95 EEC has some "softer" programming when compared to the A9L. Numerous comments about Ford wanting to soften the shock to the drivetrain at WOT so they EEC pulls 5 degrees of timing out for a short interval, stuff like that.

Could be a bunch of internet hogwash, but Pro-M made this harness just for that purpose and had some claims about drops in quarter-mile times and increases in trap speeds so there may be something to it?