Diagnosis Procedure

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

Is the inspection result normal?

YES: GO TO 2.

NO: 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: Identifying Exhaust Gas Leakage
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Is exhaust gas leak detected?
  
  YES: Repair or replace.
  
  NO: GO TO 3.
CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.

Is intake air leak detected?

YES: Repair or replace.

NO: GO TO 4.

CHECK IGNITION TIMING

Check the following items. Refer to "BASIC INSPECTION : SPECIAL REPAIR REQUIREMENT ".

ITEM SPECIFICATIONS

Items	Specifications
idle speed	700 ± 50 rpm (in P or N position)
Ignition timing	15 ± 5° BTDC (in P or N position)

Is the inspection result normal?

YES: GO TO 5.

NO: Follow the "BASIC INSPECTION : SPECIAL REPAIR REQUIREMENT ".

CHECK FUEL INJECTOR

Stop engine and then turn ignition switch ON.

Check the voltage between ECM harness connector and ground.

CONNECTOR TERMINAL VOLTAGE CHART

ECM		Ground	Voltage
Connector	Terminal	Ground	Voltage
F7	29	Ground	Battery voltage
	30
	31
	32

Is the inspection result normal?

YES: GO TO 6.

NO: Perform "DIAGNOSIS PROCEDURE ".

CHECK FUNCTION OF IGNITION COIL-I
CAUTION: Perform the following procedure in a place with no combustible objects and good ventilation.
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.
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 5 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 (0.52 - 0.66 in) between the edge of the spark plug and grounded metal portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether spark is generated between the spark plug and the grounded metal portion.
  Spark should be generated.
  CAUTION:
  - Never place the spark plug and the ignition coil within 50 cm (19.7 in) each other. Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20kV or more.
    
    Fig 2: Checking For Spark
    Courtesy of NISSAN MOTOR CO., U.S.A.
  - It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
  NOTE: When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunctioning.
  
  Is the inspection result normal?
  
  YES: GO TO 10.
  
  NO: GO TO 7.
CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug.
3. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.
  Spark should be generated.
  
  Is the inspection result normal?
  
  YES: GO TO 8.
  
  NO: Check ignition coil, power transistor and their circuits. Refer to "DIAGNOSIS PROCEDURE ".
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.

Fig 3: Checking Spark Plug For Fouling
Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal?

YES: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "REMOVAL AND INSTALLATION ".

NO: Repair or clean spark plug. Then GO TO 9.
CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark plug and the grounded portion.
  Spark should be generated.
  
  Is the inspection result normal?
  
  YES: INSPECTION END
  
  NO: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "REMOVAL AND INSTALLATION ".
CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly.
  Refer to "REMOVAL AND INSTALLATION ".
  
  Keep fuel hose and all fuel injectors connected to fuel tube.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON.
  Does fuel drip from fuel injector?
  
  YES: GO TO 11.
  
  NO: Replace the fuel injector(s) from which fuel is dripping.
CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".

Is the trouble fixed?

YES: INSPECTION END

NO: Replace three way catalyst assembly.