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Home >> GMC >> 1995 >> Forward Control 6.5 Y, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing - 6.5L Diesel >> Basic Fuel System Checks >> Fuel System Pressure Test
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Fuel System Pressure Test

  1. Turn engine off. Disconnect fuel line at inlet to fuel filter assembly. Install low pressure fuel gauge to fuel line.
  2. Crank or run engine 10-15 seconds. If fuel pressure is not 5.8-8.7 psi (.41-.61 kg/cm2 ), check fuel lines and fuel tank sending unit for restriction. If fuel lines and sending unit are okay, replace fuel pump.