Maf Conversion

Mavros

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Nov 17, 2014
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I just bought an 88 5.0 5 speed last week. It is my second Mustang, I had an 02 a few years ago.
It came with a computer and wiring harness for the MAF conversion along with 24lb injectors. I have to get a chip for the computer to run the new injectors because the MAF is calibrated to the 24s as well. Just wondering if there is anything else I need to do to complete this conversion? Also can you guys recommed and company to get my chip from?
I got some big plans for this fox but first i want to get this conversion done while I build a stronger block.
Thanks
 
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Hold off on the 24lb injectors for a while, you wont need them yet. You can convert to mass air with only a mass air computer, a few plug switches on your computer harness and a mass air meter. You don't have to change the harness. "jricker?" has all the spec, I'm shure he will reply .. I have them printed out some where, but I don't have them save on my computer. Just so you don't make the same mistake I did, make shure your mass air meter wires are away from your exhaust... They melted and shorted out the computer
 
MASS air conversion instructions from http://www.stangnet.com/tech/maf/massairconversion.html FREE

Revised 2 Aug 2014 to add new links to conversion harness suppliers, diagram for repining computer wiring connector and YouTube video

A9L (5 Speed) computer from junkyard $100-$150
A3M (5 Speed) computer from junkyard $100-$150
A9P (Auto or in a pinch, it will work in a 5 Speed car) 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://www.latemodelrestoration.com...ustang-50L-Mass-Air-Conversion-Wiring-Harness

Youtube video how to do a Mass Air conversion using a conversion harness kit (somewhat long but useful)

View: http://www.youtube.com/watch?v=mnnTgXkHU9Q


Some more help... http://www.hotrod.com/pitstop/hrdp_0705_pitstop_ford_thunderbird_mass_air_sensor/photo_01.html

hrdp_0705_26_z%2bford_thunderbird_harness%2b.jpg


Wire side 60 pin computer wiring harness connector
a9x-series-computer-connector-wire-side-view-gif.71316


Computer side 60 pin computer wiring harness connector
eec-iv-computer-connector-for-5-0-mustang-gif.88243



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. (because 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 may be compatible (single dash connector, fuel pump relay under the hood). You may end up running some extra wire for the fuel pump relay. Comments and input from someone who has actually used the 92-93 EFI harness would be nice.

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 $40-$45 depending on if it’s on sale or not. 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.
 

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Do you even need to convert at this point?

Stock vs stock, speed density is a much more aggressive comp setup than Mass air.

So if your mod list is low, and you aren't planning a supercharger or cam swap in the near future, it would be better to leave the SD setup with 19's vs swap to MA and run 24's. I have a pretty healthy list of bolt-ons on my '88 and still run Speed Density. Runs strong and idles smoothly. No issues at all.

Oh and if the MAF is calibratrd for 24# injectors, you do not need a chip. However, what brand MAF is it would be a good question to have answered
 
I'll just hold off for awhile, it does run a little rich so that was the main reason I figured the conversion would be good. It's just a stock ford MAF that I am 'trusting' the previous owner told me it was 24s
 
Some help to determine what injectors you have...


Diagrams courtesy of Tmoss & Stang&2birds

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
Ford_Injector_Guide.jpg


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/ Everyone should bookmark this site.

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

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

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif

T5 Cutaway showing T5 internal parts
http://www.veryuseful.com/mustang/tech/engine/images/5_Speed_Cutaway_Illustrated.jpg

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg
 

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I picked up a a9p for my 87, so all I would need is a 94-95 gt sensor and the harness from late model?

My car runs rich, but I am doing a 331 stroker next year, so I wanted a bit more to work with when I have it tuned.
 
Google "IST mass air" and you'll find a conversion harness you can use.

Using a factory harness means using an entire 1989 engine harness, or swapping to a 1990 engine and body harness.

The IST harness much easier and cheaper