Electrical 93 To 88

Discussion in 'Fox 5.0 Mustang Tech' started by jesse325, Dec 11, 2013.

  1. wheel a 93 EEC wire harness fit my 88??
  2. No..
    Only 87-89
  3. If you are going to keep the Speed Density computer you already have, only an 87 or 88 5.0 Mustang wiring harness will work.

    If you are doing a Mass Air conversion, the following will work for you.

    MASS air conversion instructions from http://www.stangnet.com/tech/maf/massairconversion.html FREE

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

    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 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.
  4. what's the differences between mass air and speed density?
  5. Somehow I figured that question was coming...

    5.0 Mustangs made between 1986-88 were Speed Density.
    The California 1988 5.0 was the exception, it was Mass Air.
    1989-95 5.0 Mustangs were all Mass Air .

    Speed Density uses Manifold vacuum (MAP), Throttle position (TPS) and RPM, & Air Temperature (ACT) to guess how much air the engine is pulling in. Then it uses all of them plus the O2 and ECT sensors to calculate the air/fuel mixture. It is dependent on steady manifold vacuum and minimal changes in airflow from the stock engine configuration to maintain the proper air/fuel ratio. Change the airflow or vacuum too much and the computer can't compensate for the changes, and does not run well. Forget about putting a supercharger, turbocharger or monster stroker crank in a Speed Density engine, because the stock computer tune won’t handle it. Every time you seriously change the airflow through the engine, you need a new custom burned chip to make the engine run at peak performance.

    Mass Air uses a Mass Air Flow meter (MAF) to actually measure how much air is being pulled into the engine. The computer uses this information and inputs from the O2, TPS, ACT, ECT, RPM and Barometric Pressure (Baro) sensors to calculate the proper air/fuel ratio. It is very tolerant of changes in airflow and vacuum and tolerates wild cams, high flowing heads, and changes in displacement with minimal difficulties. Larger injectors can be used with an aftermarket calibrated MAF or a custom dyno tune. This makes it possible to use the stock computer with engine displacements from 302-408 cu in, and make many modifications without a custom dyno tune chip. Put a new intake manifold on your 331 stroker and the computer figures out how much more fuel to deliver without having to have a new chip burned to accommodate the extra airflow.

    If you plan for major engine modifications and have the money to pay for them, a Mass Air conversion is one of the first steps to make. First before you do any major engine modifications, get the Mass Air conversion running good with no major codes or odd problems. Then you can change the cylinder heads, camshaft and intake manifold and not run into major computer problems. You won't end up struggling to get the engine to run right because of a computer program that can't adapt to your new modifications.

    Note in the picture below the funny looking gizmo between the air filter box and the rubber ducting that connects to the throttle body. That's the MAF.

    View attachment 121589
    #5 jrichker, Dec 12, 2013
    Last edited: Dec 12, 2013
  6. OK someone has already done the maps air on it just did a :poo:y wire job guess I gotta pull it out and look at the right tmoss wire diagram thankyou much
  7. I don't think wheels had computers, but I could be wrong..lol

    Anyway, the answer is no- for a number of reasons. Different O2 sensor, airbag, fuel pump relay connections , speed density vs Mass Air unless its a later 88 or California car, T5 vs. AOD harness/ Get the picture.... a world of difference.

    Chances are with a 25 year old car, your harness is hacked up in some manner, or many of the connections are broken. Follow jrichkers post. First look under the hood and onthe intake tube see if you have a mass air sensor. Look to see if you have smog equipment, O2 sensors. EGR valve on the back of the throttle body. Maybe post some pictures if you can't tell.

    Your computer is located in the passenger kick panel. It should have a sticker on it. If your car has Mass Air it is either an A9L - stick, or A9P- AOD.