C 30 1 Ton Pickup 2WD V8-350 5.7L VIN M 4-bbl (1983)
Manifold Pressure/Vacuum Sensor: Specifications
MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS
Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected
between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over
it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models.
Barometric Pressure Sensors: Measure voltage with ignition on and engine off.
Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage
should be 1.2-2.3 volts less.
Pressure Sensors: Measure voltage as indicated.
