Diagnostic Procedure

CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.

OK or NG

OK: GO TO 2.

NG: Repair or replace.
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).
  
  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.
CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.

OK or NG

OK: GO TO 4.

NG: Repair or replace.

CHECK IGNITION TIMING

Check the following items. Refer to "BASIC INSPECTION ."

TARGET IDLE SPEED AND IGNITION TIMING SPECIFICATION

Items	Specifications
Target idle speed	600 ± 50 rpm (in P or N position)
Ignition timing	15 ± 5° BTDC (in P or N position)

OK or NG

OK: GO TO 5.

NG: Follow the "BASIC INSPECTION ."

CHECK FUEL INJECTORS
1. Stop engine and then turn ignition switch ON.
2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42 and ground with CONSULT-III or tester.
  Refer to WIRING DIAGRAM for fuel injectors .
  
  Voltage: Battery voltage
  
  Fig 2: Checking Voltage Between ECM Terminals 21, 22, 23, 40, 41, 42 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: GO TO 6.

NG: Perform "DIAGNOSTIC PROCEDURE ."
CHECK FUNCTION OF IGNITION COIL-I
CAUTION: Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
  NOTE: Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following procedure.
  
  Fig 3: Identifying Fuel Pump Fuse In IPDM E/R
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Start engine.
4. After engine stalls, crank it 2 or 3 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 4.
  
  Fig 4: Identifying Gap Between Edge Of Spark Plug And Grounded Metal Portion
  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 more than 17 mm is taken.
  NOTE: When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG

OK: GO TO 10.

NG: GO TO 7.
CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 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 SIGNAL ."
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.

Fig 5: Identifying Spark Plug Tip
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.
CHECK FUNCTION OF IGNITION COIL-MI
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 "SPARK PLUG (PLATINUM-TIPPED TYPE) ."
CHECK INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly.
  Refer to "FUEL INJECTOR AND FUEL TUBE ."
  
  Keep fuel hose and all fuel injectors connected to fuel tube.
3. Reconnect all fuel injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Turn ignition switch ON.
  Make sure fuel does not drip from fuel injector.
OK or NG

OK (Does not drip.): GO TO 11.

NG (Drips.): Replace the fuel injector(s) from which fuel is dripping.
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ."

Trouble is fixed. >>INSPECTION END

Trouble is not fixed.: Replace three way catalyst assembly.