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Fuel Injector Solenoid

  1. Disconnect injector solenoid connector. Measure resistance across solenoid terminals. Resistance should be at least 1.2 ohms.
  2. If resistance is less than 1.2 ohms, replace injector and ensure fuse in circuit No. 439 (Red/White/Black wire) is not blown. Check for 12 volts on circuit No. 439 with ignition on. See Fig 1 . Ensure fuel pressure at injector is 9-13 psi (.6-.9 kg/cm2 ). See FUEL PRESSURE in BASIC DIAGNOSTIC PROCEDURES article.
  3. With injector connector disconnected, crank engine. If injector sprays or drips fuel, replace injector or injector "O" ring. Connect a fuel injector test light to injector connector and crank engine. If test light blinks, reconnect harness to injector and crank engine.
  4. If fuel injector tester does not blink, check for short to ground in ECM circuit D9-D10 (peak and hold jumper). See Fig 1 . If short is present, repair circuit or replace ECM. With ignition on, if both terminals on fuel injector test light are off, repair open in circuit No. 439. If both terminals on fuel injector test light are on, repair short to voltage in circuit No. 467.
Fig 1: Injector & Ignition System Circuits
G90F15540Courtesy of GENERAL MOTORS CORP.