HELP need....changing over to mass air on 87 gt

MYSTICCOUPE

New Member
Sep 11, 2005
1
0
0
i have a 87 gt, that im trying to change over to mass air.. i got everything out of a 91 mustang. i changed over all the wiring harness and the computer, and all the mass air parts..
1-there is one plug down by the computer that was not on the 87 harness..what does this plug go to?? ( I've been told that its for the airbags and not to worry and it) but i dont know..
2-when i got everthing hooked up (besides that plug by the computer) the fuel pump wont come on..
has anyone done this, and what all do i have to do??? thanks
 
  • Sponsors (?)


If something is not grounded the fuel pump wont prime, may want to look at your connections again. I have no idea about the extra plug though. Could that be a ground, or is it an actual plug.
 
Did you swap the over the entire car wiring harness or just the engine harness? If you just swapped out the engine harness your car WILL NOT WORK.

If this is the case then the easiest thing to do is just add the maf wires to your original harness and change the few pins that need to be changed as well. There used to be guides on here and on corral about which pin positions have to be changed on the plug that goes into the computer.

Good luck.
 
MASS air conversion instructions from http://www.stangnet.com/tech/maf/massairconversion.html FREE
A9L (5 Speed) computer from junkyard $100-$150
A9P (Auto or in a pinch, 5 Speed) computer from junkyard $100-$150
70MM MAF from 94-95 Mustang GT - $40-$70
MASS Air wiring harness kit $30-$85

The whole thing is probably less than $300 using junkyard parts.

A9L computers are 5 speed only
A9P computers are automatic, but will work with a 5 speed.

Conversion Harness kits & parts
http://www.mass-air.com/
http://fordfuelinjection.com/index.php?p=54

If the idea of moving & soldering wires scares you, here's a list of compatible Mass Air wiring harnesses.
Copied From bbunt302

Just for reference, here's a list of all the compatible years:

89 harness should work for 86-89 as long as you're using mass air.
90 harness will only work in a 90. (B/c of air bags and dual dash connectors)
91 through early 92 harnesses should be compatible (single dash connector, fuel pump relay under driver's seat)
Late 92 through 93 harnesses should be compatible (single dash connector, fuel pump relay under the hood)

Computers from 89-92 are all the same. Look for the A9L sticker on the back cover for a 5 speed that matches your requirements. Example: E9ZF 12A650 AA" with the A9L code.

The extra connector may be for the Mass Air Sensor.

The following is typical of the mass air harness. It may or may not match the one you have.
Diagram courtesy of Tmoss & Stang&2birds
mustangMainHarness.gif


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif
 

Attachments

  • mustangMainHarness.gif
    mustangMainHarness.gif
    84.7 KB · Views: 98