Bought my first 'stang from an friend. A wrecked '89 HO 5.0. Put that motor in an '87. Doesn't have a MAF and the computer is giving me fits. Is there a harness and a sensor I need to add or is there another fix? Please help!
If you're using the '89 computer, you will need a Mass Air conversion kit. It has a mass air sensor, housing and bracket, and harness. There is also a wire or two which need their positions switched on the (I think) connector at the computer. You probably only want to use the '87 computer harness if it was a V8 car, originally. Also, the Mass Air system does not use the vacuum hose to the MAP sensor. Remove the hose, and cap its source. The Manifold Absolute Pressure sensor functions as a Barometric Pressure sensor with the engine vacuum source eliminated. Ideally, you could get the main harness from the '89. You can get the sensor assembly from the aftermarket.
Or, you could get an '87 5.0 Speed Density computer. If that's what you've got, make sure you connect the afore mentioned vacuum line.
The MAP/BP sensor is up around the center of the firewall.
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