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Home >> GMC >> 1988 >> Forward Control 5.7 M, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - Diesel >> Testing >> Injectors >> Test Preparation
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Test Preparation

  1. Remove injectors from engine. Clean carbon from tip area of nozzle with soft brass wire brush. DO NOT  use steel brush or motorized brush to clean nozzle tip. Damage to nozzle tip may result.
  2. Connect injector to injection nozzle tester. Place clear plastic tubing on each fuel return fitting to prevent leakoff from being confused with leaks. Close tester shutoff valve to pressure gauge.
  3. Fill tester with test fluid. Fill and flush nozzle assembly with test fluid by operating tester lever briskly and repeatedly. This purges air from nozzle and coats all parts with test fluid.
WARNING: When testing injectors, keep spray contained to avoid serious injury. DO NOT  allow injector to release line pressure on hands, arms or any part of body. Pressure of atomized test spray has sufficient penetrating power to puncture flesh.
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