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 Exhaust Gas Leak

   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 the following items. Refer to "BASIC INSPECTION ".

Fig 2: Ignition Timing Reference Chart

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

OK or NG

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

1. Let engine idle
2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42 and ground with CONSULT-II or tester.

   Refer to WIRING DIAGRAM  for Injectors.

   • Battery voltage should exist 

OK or NG

• OK: GO TO 6.
• NG: Perform "DIAGNOSTIC PROCEDURE ".
  Fig 3: Checking Voltage Between ECM Terminals 21, 22, 23, 40, 41, 42 & Ground

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

1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
   Fig 4: Removing Fuel Pump Fuse

   Courtesy of NISSAN MOTOR CO., U.S.A.
   NOTE: Do not use CONSULT-II to release fuel pressure, or fuel pressure applies again during the following procedure.
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 the figure.
    Fig 5: Measuring Gap

    Courtesy of NISSAN MOTOR CO., U.S.A.
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.
    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  10.
• 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 "INJECTOR CIRCUIT ".

Check the initial spark plug for fouling, etc.

Fig 6: Checking Spark Plug For Fouling

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

OK or NG

• OK: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "CHANGING SPARK PLUGS (PLATINUM - TIPPED TYPE) ".
• NG:
  1. Repair or clean spark plug.
  2. GO TO 9.

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 (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 11.
• NG (Drips.): Replace the injector(s) from which fuel is dripping.

Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

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