The Adventures of Owning a Foxbody Mustang (Part 3): We Need More Air!

After setting my Mustang on fire while trying to fix it, I finally got it back up and running. All good things must come to an end, however, and 15 minutes after the new distributor was put in, my mass air flow meter (MAF) broke.

My mechanical wizard Mauricio came to this conclusion after we put a new distributor in the Mustang, solving the lack of spark issue, and she was still running rough. After some poking around in the engine bay, Mauricio unplugged the electrical connector to the MAF and she ran 1000% better.

By unplugging the MAF, the Mustang’s ECU must use pre-determined settings to deliver air and fuel to the engine, rather than real-time data from the MAF. This trick comes in handy when you are a poor high school student and can’t afford a new MAF until next pay-day.

Driving the car without a MAF was a little nerve-racking. I’m guessing the Mustang’s pre-determined air/fuel settings didn’t account for a big cam in the engine because the idle would surge from about 300rpm to 1500rpm at stoplights, sometimes even stalling out. The fear of stalling led me to be lightly pressing the gas with the side of my foot at stoplights in heel-toe fashion, not a very comfortable position for minutes on end. Once I got up to speed, however, it drove like a normal car and seemed to run pretty well.

Finally pay-day arrived and I ordered a brand new BBK mass air flow meter pre-calibrated for my car’s 24lb fuel injectors, an upgrade from the stock 19lb ones. I installed the new MAF and off I went. No more check engine light! I decided to celebrate the end of stalling out at stoplights with a good ol’ fashioned 0-60 pull. And then, disaster!

Ain’t she pretty?

The car was wheel-hopping like crazy, or so I thought, and basically undriveable at wide open throttle. After angrily driving to the gas station, the Mustang’s favorite place, I did some thinking. I figuredthat if it was actually wheel hop, it shouldn’t happen on the highway, where I should have plently of traction at 60mph. So I dropped it into 3rd on the highway and it did the same thing! The Fox is fast(ish) but not powerful enough to break traction at 60 so I knew it had to be something else.

I pulled over and unplugged the shiny new MAF to test if it was somehow broken already and went to do another pull. Behold! No wheel hop! I was very mad at this point. Not only was I wrong about the wheel hop (it was actually the MAF cutting fuel at wide open throttle) but I had a broken MAF! I spent $200 on a fancy BBK mass air flow meter and they have the gall to send me a broken one? I drove back to the gas station, having burned half a tank doing my testing, and planned my revenge on BBK for cursing me with a broken MAF.

It was too late to call BBK at that point so I decided to poke around under the hood to see what I could see. I picked up the MAF electrical connector, a 6 pin plug spliced into the wiring harness, and I saw the culprit of my troubles! Dirt. The connector was full of grease and dirt, causing it to have a bad connection to the MAF. This, in turn, was causing the MAF to get a bad reading, hence the fuel cut at wide open throttle.

The culprit!

I cleaned the connector and plugged it back in, my problems were gone. I felt very stupid for letting a few grains of dirt ruin my day but at least the Fox was fixed. There is never a dull moment when you own a Foxbody Mustang.

 

  • B Mathew Martinez

    I have a 88, Love it. So easy to work on and fun to rip around in. But mine is dead reliable. Far more reliable than my new-ish Audi (which sucks)