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Home >> Isuzu >> 2001 >> Rodeo LS, 2.2 D >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel System >> Fuel Injector Balance Test >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform On-Board Diagnostics II (OBD-II) System Check. See appropriate SELF-DIAGNOSTICS article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
  2. Turn ignition off. Release fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE procedure in REMOVAL, OVERHAUL AND INSTALLATION article. Connect Fuel Pressure Gauge (J 34730-1) to test port on injector rail. Turn ignition on, with engine off. Using scan tool, energize fuel pump. Place bleed hose of fuel pressure gauge in container. Bleed air from hose. Energize fuel pump. Continue to energize fuel pump until highest pressure is observed. If fuel pressure is 43-55 psi (296-376 kPa), go to next step. If fuel pressure is not within specifications, see appropriate FUEL SYSTEM DIAGNOSIS procedure in BASIC DIAGNOSTIC PROCEDURES article.
  3. Connect Fuel Injector Tester (J 39021-5V) and Injector Switch Box (J 39021-90) to fuel injector harness. Set amperage supply selector switch of Fuel Injector Tester to 0.5-2.5 amp position.
  4. Using scan tool, turn fuel pump on then off. Record fuel pressure. Energize fuel injector by depressing PUSH TO START TEST button on fuel injector tester. Record fuel pressure after fuel pressure gauge needle stops moving.

  5. Repeat previous step for remaining fuel injectors. Subtract second pressure reading from 1st reading for each injector. The difference in readings is pressure drop value. Record pressure drop value for each fuel injector.

    Add all pressure drop values to obtain total pressure drop. Divide total pressure drop by number of fuel injectors. If any individual injectors pressure drop is greater or less than 1.5 psi (10 kPa) compared against average pressure drop, go to next step. If all individual injectors pressure drop is within specification, go to FUEL INJECTOR COIL TEST  .

    NOTE: DO NOT repeat any portion of test before running engine to prevent flooding.
  6. Retest any fuel injector that is not as specified. If faulty fuel injector drop value is still not as specified, replace fuel injector.
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