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Home >> GMC >> 1991 >> Forward Control 4.3 Z, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 4 (Engine Controls - System/Component Tests) >> Fuel System (Diesel) >> Injectors >> Opening Pressure Test
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Opening Pressure Test

WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 1992 Pontiac Trans Sport, 1992 Oldsmobile Silhouette, 1992 Oldsmobile Bravada, 1992 GMC Yukon, and 1992 GMC Vandura Special. However, it is still accessible from the selected car via links, so may be relevant.
  1. Open tester shutoff valve 1/4 turn from closed position. Slowly depress tester lever and observe gauge. Note pressure at which needle of pressure gauge stops. Some injector nozzles may pop while other injector nozzles may drip (this is not a leak).
  2. Injector opening pressure should not fall to less than 1500 psi (105 kg/cm2 ). Replace any injector nozzle that does not meet lowest acceptable pressure. Release tester pressure.