92 Mark VII ECU ok to do a HO swap into an 88 5.0 T-bird?
It should work. The 88+ Mk 7 uses some of the pins to run the on-board Cruise Control (35, 38, 39, 41, and 50) but they don't conflict with the Thunderbird pinout. They just don't get used.
You can compare them here.
http://fordfuelinjection.com/5.0Lpinouts.html
Looks like it should work, though if you want to modify it in the future, a more common ECU might offer more flexibility.
Speed limiter....
Unhuh... Ronnie(chrome 302jr) found that out when he was using one, car just laid down at something like 108mph...
NOW if the seed sensor input to the EEC is not connected, the limiter is inoperative...
Unhooking the VSS has the same effect, does it not? Track purposes and whatnot...
I had vss unhooked on my a9p and had issues, I think.
It would just break up, like big time valve float, but not all the the time. since I hooked it up never had that problem again.This was on a 87.
Speed limiter comes in at 117...chances are, if you have a 12-second t-bird, it's not running a Mark VII ECU. I clipped the wire near the ECU...i want to say it was a solid green...it's been so long I can't remember. That way your speedo stays functional and your ECU is none-the-wiser...it did idle a little high when coming to stops sometimes...no major issue though.
The A9P (a MAF computer, which I run as well) needs the VSS input to function correctly. A SD computer does not, except for the speed limiter. The nice thing is I didn't have to run VSS wires in my car when I did the MAF swap as the 88 Birds/Cats had the wires from the factory. The 87 and down cars didn't though ;)
I ran a Mark VII SD computer for a year and it worked fine for me. I couldn't break 108 in the quarter so I'm pretty sure a stock HO (if that's what he's using) won't either. Besides one shouldn't be driving 108 mph on the street any ways;) If you've got one use it or if it's easier to find use it. The engine won't know the difference.
'87 Cougar here - VSS equipped.
Hmm maybe they switched later in the 87 production run? I've seen 87 T-birds and Cougars with out the VSS pins :crazy:
Had to add them to the '87 harness that I installed in my TC... Came from a mid year car, Jan I believe...
Weren't the 20ths produced later int he run? Maybe they switched the harness late in the year?
Not sure but I had issues till I hooked it up.87's don't have it.
Like I said it felt like big time valve float, just died and back fired.
Stop shut it off restart no problems. I thought it might of been the ignition switch, same ones still in though. ic you need to wire that if you read this.
I know of 2 now that aren't . thats 87's. They need to tap the wires to the comp. 88's were wired.
+1 here. Build date 3/17/87
Also remember, the ECU in question from the original post is in fact a speed density ECU.
Dunno what your problem was, but I ran a A9P in a '86 5 speed stang with no issues and no connection to the speed sensor(the Stang didn't even have one)... It's the same one I ran in my TC till I got a A9L...