Diagnostic Procedure

Visually check exhaust tubes and muffler for dent.

OK or NG 

• OK : GO TO 2.
• NG : Repair or replace.

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
   Fig 1: Checking For Exhaust Gas Leakage

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

OK or NG 

• OK : GO TO 3.
• NG : Repair or replace.

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

OK or NG 

• OK : GO TO 4.
• NG : Repair or replace.

Check for ignition timing. Refer to "BASIC INSPECTION ".

Fig 2: Ignition Timing Specifications

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

OK or NG 

• OK : GO TO 5.
• NG : Follow the "BASIC INSPECTION ".

1. Refer to Wiring Diagram for Injectors, WIRING DIAGRAM .
2. Stop engine and then turn ignition switch ON.
3. Check voltage between ECM terminals 22, 23, 41, 42 and ground with CONSULT-II or tester.
   • : Battery voltage should exist. 
   Fig 3: Checking Voltage Between ECM Terminals 22, 23, 41, 42 And Ground

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

OK or NG 

• OK : GO TO 6.
• NG : Perform Diagnostic Procedure INJECTOR, WIRING DIAGRAM .

1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
   NOTE: Do not use CONSULT-II to release fuel pressure, or fuel pressure applies again during the following procedure.
   Fig 4: Identifying Fuel Pump Fuse

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for five seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm between the edge of the spark plug and grounded metal portion as shown in Fig 5.
11. Crank engine for about three seconds, and check whether spark is generated between the spark plug and the grounded metal portion.
    • Spark should be generated. 
    CAUTION:

    • Do not approach to the spark plug and the ignition coil within 50cm. Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20kV or more.
    • It might cause to damage the ignition coil if the gap of 17 mm or more is taken.
    Fig 5: Identifying Spark On Grounded Metal Portion

    Courtesy of NISSAN MOTOR CO., U.S.A.
    NOTE: When the gap is 13 mm or less, the spark might be generated even if the coil is malfunctioning.

OK or NG 

• OK : GO TO  9.
• NG : GO TO 7.

1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.
   • Spark should be generated. 

OK or NG 

• OK : GO TO 8.
• NG : Check ignition coil, power transistor and their circuits. Refer to IGNITION COIL & POWER TRANSISTOR .

1. Reconnect the initial spark plugs.
2. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug and the grounded portion.
   • Spark should be generated. 

OK or NG 

• OK : INSPECTION END 
• NG : Replace spark plug(s) with standard type one(s). For spark plug type, refer to CHANGING SPARK PLUGS (DOUBLE PLATINUM - TIPPED TYPE) .

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

   Make sure fuel does not drip from injector.

OK or NG 

• OK (Does not drip) : GO TO 10.
• NG (Drips) : Replace the injector(s) from which fuel is dripping.

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

• Trouble is fixed : INSPECTION END 
• Trouble is not fixed : Replace three way catalyst (manifold).