What do I need ?

[Bite_ME]

I have a 1987 Mustang GT 5.0 manual, I went to a junkyard today and found a 1990 Mustang GT 5.0 manual. What I do need to take away from it, to change my car from speed density to mass air. Also I want to change the 85 mph gauge to the 140 mph one, can I just change them ?

 

[BK_CAULEY]

pull the entire engine harness and ecm. also get the meter itself. and the gauges just swap out. there is also a module on the firewall you need to get. let me do some digging to find out what its called.

 

[LiquidGT]

^If I'm not mistaken the MAP/BAP sensor is interchangeable between MA and SD, all he needs to do is pull the vac line off and that sensor is ready for mass air.

 

[Bite_ME]

Thanks for the info, I will be pulling the parts out on Monday myself. As I traced the engine wire harness that comes out of my car through the firewall. It connects to two main connectors that seem to go inside the car on the drivers side. Here is a diagram I found hope it helps

 

[Bite_ME]

Just foundn this pic on ebay is this what I got to pull out ?

 

[BK_CAULEY]

thats it man. just make sure you pull it from a 88,89 or 90 mass air car.


man i went throught this a while back and for the life of me i cant remember the details. i just even searched my previous threads and couldnt find anything.

the 88,89 cars had no air bag and dual dash connectors (grey and black) the 90 had the same dual dash connectors and air bag provisions. in you case just dont use te air bag hook ups, well obvioulsy you cant and the 91-93's had the own stlye. they had a single brown dash connector.

i got screwed on this while doing a v8 swap on my car.

but you should be good pulling it from a 90.

 

[strtrcr50]

I was of the opinion that the only year that the harness is plug and play is 89. You always could just take the mass air pigtail, run new wires, and repin the eec.

 

[jrichker]

I was of the opinion that the only year that the harness is plug and play is 89. You always could just take the mass air pigtail, run new wires, and repin the eec.

I would do the conversion as suggested above. I reciently pulled the computer harness from my wrecked 89 GT. It was harder to get the harness out of the car than it would have been to run the 4 wires and re-pin the computer connector.

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.

The conversion harness seems to work well for most folks. It avoids the compatibility problems in using a harness from the junkyard. Simple and cheap, actually less work that swapping the wiring harness.
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)

Larger MAF to go with Mass Air conversion:
94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

*1.) Metal flange adapter http://www.kustomz.com/cat3.html Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.
Try AutoZone and ask for 81413 - Spectre / 3 in. Aluminum Intake Mass Air Flow Sensor Adapter at $12.00. You may have to order it online.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.

Also see www.forfuelinjection.com for help with the harness parts http://rjminjectiontech.com/?p=10, and connector pins, http://rjminjectiontech.com/?p=11