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Fuel Pressure Regulator

  1. Measure fuel pressure. See FUEL PRESSURE in BASIC TESTING article in the ENGINE PERFORMANCE Section. Stop engine. With fuel pressure tester still installed, measure fuel pressure after 5 minutes. If fuel pressure is greater than 21 psi (1.5 kg/cm2 ) after 5 minutes, go to next step. If fuel pressure does not remain higher than 21 psi (1.5 kg/cm2 ), fuel pressure regulator, fuel pump, or fuel injectors may be defective.
  2. Connect vacuum tester to vacuum fitting on fuel pressure regulator and apply 20 in. Hg. Replace fuel pressure regulator if vacuum does not hold. Reinstall fuel pressure regulator.
  3. Start engine. Measure fuel pressure. If fuel pressure is higher than specification, inspect for engine vacuum leaks, damage to fuel pressure regulator housing, or a restricted fuel return line. Replace fuel pressure regulator if no problems exist.