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Home >> GMC >> 1990 >> Forward Control 5.7 K, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing >> Basic Fuel System Checks (Diesel) >> Fuel Pump Flow Test
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Fuel Pump Flow Test

  1. Disconnect fuel line at fuel filter inlet. Disconnect fuel injection pump electric shut-off solenoid wire (Pink).
  2. Crank engine for 15 seconds. Fuel pump should supply approximately 1/2 pint of fuel in 15 seconds. If fuel delivery is not as specified, go to FUEL SYSTEM PRESSURE TEST.