This is a Pro-M 75MM mass air meter for your 1989-1993 Ford Mustang 5.0L equipped with 19 LBS injectors. These mass air meters include the electronics that some other companies leave out making for a quick 'Plug -and-Play" installation. This is a great way to bolt on 8-15 extra horsepower.
* This part number is designed to work with a fender well cold air intake system!
Mustang GT/LX Mass Air Conversion Review & Install (86-88 5.0L)
Mustang GT/LX Mass Air Conversion Review & Install (86-88 5.0L)
Check out our YouTube channel for even more tech tips, installation videos, how-tos, and more. The best place to go for anything Mustang related!
Published on 2015-03-10 In this video, JMAC breaks down Pro-M's Mass Air Conversion Harness for your 86-88 5.0L Fox Body!
If you've been around the Fox Mustang community, you have likely heard of a mass air conversion. The necessity of this swap comes in when you decide to change camshafts, increase displacement, changing injector size, or otherwise modify the car in a way the manifold vacuum will be altered.
This mass air meter conversion wiring harness was developed to allow the use of a mass air meter on cars that were originally equipped with a speed density air intake setup. It comes complete with wiring, looming and easy to follow installation instructions.
- Requires use of a mass air PCM - Some wire splicing is required
[MUSIC PLAYING] If you've been around the Fox Mustang community, you've likely heard of a mass air conversion. A mass air conversion pertains to '86 to '88 Mustangs that were originally equipped with a speed density system. The necessity of the swap comes in when you decide to change camshafts, increased displacement, or otherwise modify the car in a way the manifold vacuum will be altered or injector size will be changed.
To perform this swap, you'll need a conversion harness, cold air kit, and a mass air sensor assembly, all available on our website. You'll also need a mass air compatible PCM. For manual transmission cars, use an A9L or A3M processor. And for automatic cars, use A9P or C3W processors.
The difference in PCM versus transmission comes from differences in the O2 sensor harness that can cause PCM failure if the two are intermixed.
The conversion harness we offer comes with printed instructions, so what follows are video highlights of each step in the process.
Before you begin installation, disconnect the negative battery cable. Remove your existing air inlet system and install a mass air-tightened induction, like the cold air kit that we have here.
Take your mass air meter and slide it into the coupler, making sure the meter electronics are parallel to the ground. Finish installing you inlet system and tighten all the clamps.
Locate the rubber firewall grommet for the PCM harness. Using a long screwdriver, carefully puncture the boot and remove the screwdriver. From inside the car, find the puncture hole you created in the grommet and feed the screwdriver through it.
Using quality electrical tape, attach the mass air conversion harness to the tip of the screwdriver, making the tape wrap as smooth as possible. From inside the car, carefully pull the screwdriver back through the grommet, pulling the wires through. Remove the tape from the harness.
Remove your kick panel along with the PCM and remove the electrical connector from it. Release the four retaining tabs and remove the black, plastic harness guard. Using a small pick or similar tool, remove the red, plastic pin retainer from the PCM harness plug.
Locate the red wire running to either pin 37 or 57 of the PCM connector. We use pin 57. Cut the PCM harness wire and slice in the red wire from the mass air conversion harness into the PCM harness using a butt connector or by soldering.
Locate the black wire running to either pin 40 or 60 of the PCM connector. We used pin 40. Cut the PCM harness wire and splice in the black wire, from the mass air conversion harness into the PCM harness, using a butt connector or by soldering.
Click the pre-terminated tan wire from the mass air conversion harness into the empty terminal location number nine. Click the pre-terminated blue wire from the mass air conversion harness into the empty terminal location number 50.
Locate the white wire with the red tracer located in the number 51 position. Using a tiny pick, release the terminal lock and remove the wire from the connector. This bar will be snapped into place at empty terminal location number 38.
Locate the green wire, with black tracer, located in the number 11 position. Using a tiny pick, release the terminal lock and remove the wire from the connector. This wire will be snapped into place to terminal location number 32.
Reinstall the red pin retainer by simply pushing it back into place. Group the harness together and reinstall the black plastic PCM harness guard. Back under the hood, make a few tape wraps around the mass air conversion harness to keep the wires together.
Route your harness where you'd like it. Pull any slack you need from inside the car. Install the supplied split-loom tubing onto the harness. Cut it to length and retain the end with electrical tape. Make a wrap around the harness, route the tape through the split in the loom, and the tape the loom.
Plug in the conversion harness to the mass air. Pull any extra harness slack back into the car. To keep things nice and neat, use a few zip ties to keep everything together. Reconnect the PCM to the harness and slide your PCM back into place and reinstall the kick panel.
Remove the vacuum hose running from the intake manifold to the map sensor. This will now function as a barometric air pressure sensor. Plug or cap off the open vacuum hose or port. Reconnect the negative battery cable, double check your work, and you're all done.
Latemodelrestoration.com is your source for all things related to Fox Mustangs. Be sure to subscribe to our YouTube channel, follow us on social media, like Facebook, and, of course, check out our website for all sorts of awesome Mustang products and content.
Should I be using a better mass air meter with gt40 upper and lower with gt40 heads and comp cam xe276. I just bought car. It still has stock fuel pressure regulator and stck mass air meter. Asked by William K.from Havre de Grace | Comment00
Best Answer: With those mods, you will definitely notice an improvement with one of these mass air meters. Answered by Karson S.from Hewitt | Comment00
Pro-M always does the trick and is so much less restrictive over the OEM. I like the fact that you can send in your MAF meter to Pro-M and recalibrate it if you ever upgrade to larger injectors as opposed to buying a whole new MAF. The only thing that sucks is that the screen inside the MAF tore easily.
Yes, I would recommend this item to a friend!
Was this review helpful to you?
craig f. on
My old maf was bad so this made a huge difference! Idles perfect with no off idle stumbles. I combined it with a 3.5" Anderson Power Pipe. Car pulls hard now!
Pro-M Racing was founded in 1989 by Bob Atwood, a Ford engineer who was instrumental in pioneering mass air technology. Pro-M quickly became the most respected name in the industry, offering the only real practical solution to the restrictive production mass air meters found in most of today's production Mustangs. We manufacture mass air meters in various sizes, shapes, and styles, as both direct bolt-in replacements, and in universal designs, to maximize your engine's horsepower potential, by allowing your engine to breathe to its fullest potential. Each mass air meter is individually calibrated specifically for you Mustang or Lighting application on one of our in-house flow benches specific to your particular application, and fuel injector size, eliminating the need for time consuming and expensive dyno tuning. Others make claims, but only Pro-M Racing possesses both the intellectual and physical properties necessary to calibrate your mass air meter to within two percent of what the OEM considers the perfect baseline.
Everytime I have delt with LateModel, it seems to get better and better. I have had all positive experiences which is much more than i can say about Summit, or American Muscle. I like the mom and pop shop feel i get when i deal with LateModel. We had a family buisness turning wrenches and a huge part of our success was customer service. Specifically treating every single female as how we would want our sister of mother treated when going to a buisness. We were always more than fair, accommodating and made sure to make all of our customers leave with a smile. And it worked. 30 years later my brother is still in buisness. Yesterday, I got that same type of treatment by Ian. Thank you Ian, you really went above and beyond like this was your personal buisness. Late Model, you just def locked in another lifelong customer thanks to Ian. Semper Fi