A9P Vrs A9L mass air 'puters.

1987stangman

Member
Jul 12, 2006
684
24
19
Ok guys, I've got a 87' SD GT and I have put off converting to mass air for a few years now because with my setup was really not an issue but now I have heads and cam in the works so right now I want get the conversion done and tried and true until Jan when I get the $$$ to get the stuff I want.

Here is my main question. I scored a A9P computer from a auto car. It was a lucky find in a j-yard that I frequent BUT I have a 5speed car. I hear you can use this computer with no trouble but I want to retain my factory cruise and as particular as I am want no issues from the install. I plan to make my own harness and do the soldering per the article I found on this site. From those that have used this computer in a 5 speed car what is the diff between the A9P and the stick car A9L?

I also heard from reading several articles that the A9P is the most aggressive computer that Ford made for the Fox which I have a hard time believing because it is for an auto car that lacks the quickness of a 5 speed car (stock anyway). Maybe that is the point?
 
  • Sponsors (?)


a9p has a little more agressive spark in the lower loads to help the AOD out.

untuned... a9p probably would be a better ECU to run for performance.

from a tuning standpoint it doesnt really matter. you can change whatever you want...

as far as running either ECU on auto or manual, AFIAK it doesnt matter.
the EEC-IV doesnt have any sort of transmission control in them. you can run an AOD behind an a9L AFAIK, someone who knows for sure will have to chime in. i ran an a9P untuned when i went to a t5 from and AOD and it worked fine.
 
a9p has a little more agressive spark in the lower loads to help the AOD out.

untuned... a9p probably would be a better ECU to run for performance.

from a tuning standpoint it doesnt really matter. you can change whatever you want...

as far as running either ECU on auto or manual, AFIAK it doesnt matter.
the EEC-IV doesnt have any sort of transmission control in them. you can run an AOD behind an a9L AFAIK, someone who knows for sure will have to chime in. i ran an a9P untuned when i went to a t5 from and AOD and it worked fine.


I guess I will install it then soon. I just picked up locally a stock mass air meter, air cleaner assy. and bracket for 50 bucks.