Diagnostic Procedure

1. CHECK EXHAUST SYSTEM 

   Visually check exhaust tubes and muffler for dent.

   OK or NG 

   1. OK >>GO TO  2.
   2. NG >>Repair or replace.
2. CHECK EXHAUST GAS LEAK 
   1. Start engine and run it at idle.
   2. Listen for an exhaust gas leak before the three way catalyst (manifold).

   OK or NG 

   1. OK >>GO TO  3.
   2. NG >>Repair or replace.
3. CHECK INTAKE AIR LEAK 

   Listen for an intake air leak after the mass air flow sensor.

   OK or NG 

   1. OK >>GO TO  4.
   2. NG >>Repair or replace.
4. CHECK IGNITION TIMING 
   Fig 1: View Of Target Idle & ignition Timing

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   1. OK >>GO TO  5.
   2. NG >>Follow the Basic Inspection  .
5. CHECK INJECTORS 
   1. Stop engine and then turn ignition switch ON.
   2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42, 44, 63 and ground with CONSULT-II or tester.

      Refer to Wiring Diagram  .

   1. Battery voltage should exist. 

   OK or NG 

   1. OK >>GO TO  6.
   2. NG >>Perform Diagnostic Procedure  .
      Fig 2: Checking For Battery Voltage

      Courtesy of NISSAN MOTOR CO., U.S.A.
6. CHECK IGNITION SPARK 
   1. Turn ignition switch OFF.
   2. Disconnect ignition coil assembly from rocker cover.
   3. Connect a known-good spark plug to the ignition coil assembly.
   4. Disconnect all injector harness connectors.
   5. Place end of spark plug against a suitable ground and crank engine.
   6. Check for spark.
      Fig 3: Checking For Ignition Spark

      Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   1. OK >>GO TO  7.
   2. NG >>Check ignition coil with power transistor and their circuit. Refer to IGNITION SIGNAL  .
7. CHECK INJECTOR 
   1. Turn ignition switch OFF.
   2. Remove injector assembly.

      Refer to FUEL INJECTOR AND FUEL TUBE .

      Keep fuel hose and all injectors connected to injector gallery.

   3. Disconnect all ignition coil harness connectors.
   4. Reconnect injector harness connector.
   5. Turn ignition switch ON.

      Make sure fuel does not drip from injector.

   OK or NG 

   1. OK (Does not drip).>>GO TO  8.
   2. NG (Drips).>>Replace the injector(s) from which fuel is dripping.
8. CHECK INTERMITTENT INCIDENT 

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

1. Trouble is fixed. >> INSPECTION END 
2. Trouble is not fixed. >> Replace three way catalyst assembly.