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I'm Lost On The Map


igya
06-20-2008, 10:28 PM
Has anyone experienced a problem with the Manifold Air Pressure sensor. Can the MAP be checked in any way to see if it's working? I assume that it could cause a rich mixture, right?

91Caprice9c1
06-22-2008, 04:41 PM
A MAP sensor that has completely stopped working will set a MIL, and cause very poor driveability. It may be a bit out of range, which could cause poor fuel economy, but basically to test the sensor, you must backprobe the signal wire using a Digital Volt/Ohm Meter, and use a vacuum pump to apply vacuum to the sensor.

The ECU sends 5 volts reference to the sensor, and based on engine load, the sensor varies the output (signal) voltage. Low manifold pressure should give low voltage and high manifold pressure should give high voltage.

-MechanicMatt

igya
06-24-2008, 07:33 PM
A MAP sensor that has completely stopped working will set a MIL, and cause very poor driveability. It may be a bit out of range, which could cause poor fuel economy, but basically to test the sensor, you must backprobe the signal wire using a Digital Volt/Ohm Meter, and use a vacuum pump to apply vacuum to the sensor.

The ECU sends 5 volts reference to the sensor, and based on engine load, the sensor varies the output (signal) voltage. Low manifold pressure should give low voltage and high manifold pressure should give high voltage.

-MechanicMatt
WOW! I couldn't have asked for better directions. Many thanks!!!

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