W150 1/2 Ton Pickup 4WD V8-318 5.2L VIN Y FI (1988)
Manifold Pressure/Vacuum Sensor: Specifications
All models with TBI.
Apply 5" (125mm) Hg to unit and record output voltage. Apply 20" (500mm) Hg to unit, the difference in voltage should be 2.3 - 2.9.