Runs fine with mass air unplugged

93stang burden said:

I ve been reading and today tried to unplugg the mass air and run the car. To my suprise the car idled GREAT!! This was the first time since the new motor was installed in April. It idled @ about 850 rpm with the little rumble of the cam in it. I drove it to the gas stationed with it unplugged it missed alittle bit of the pickup and go with it unplugged but no spark knock and no dying at red lights. So before i pay 200 plus for a new 30 lb injector mass air should I try anything else. Because if i spend 200 bucks and it don't fix something I think she will kill me.

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it might run fine but its not good for it...your gonna make a whole lot of trips to that gas station so plan a faster route with that maf unplugged
and if you need a 30lb maf i'll hook ya up with one...i got 6 or so...

Yeah it's running pig rich with it unplugged..

Whats your initial problem? Limp mode is using default guessed values for your air/fueling rather than actually reading the incoming air from the maf. To me it sounds like your maf is faulty or not calibrated correctly to your injectors to the point where the fail limp mode is actually closer to what the car needs. And yes you shouldnt use the car with the maf disconnected for any prolonged time.

Code 26 - Mass Air Flow out of range – MAF

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables.

The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

Look for 12 volts across pins A & B.

The MAF output varies with RPM which causes the airflow to increase or decease. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow. Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer.

At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt

Check the resistance of the MAF signal wiring. Pin D on the MAF and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.

There should be a minimum of 10K ohms between either pin C or D on the MAF and ground.

The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF sensor can upset the computer's calibration

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

Did you try the cheap stuff first like cleaning the maf thermisistor with rubbing alcohol and a q-tip. If you have an aftermarket air filter that is oiled, over time the oil sticks to the sensor and screws with its sensing abilties. Also did you clean the terminals on both the harness and the connector of the maf using the same cleaning solution.