Diagnosis Procedure

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

OK or NG

OK: GO TO 2.

NG: Repair or replace.
CHECK EXHAUST GAS LEAKAGE
1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before the three way catalyst (manifold).
Fig 1: Checking Exhaust Gas Leakage
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 3.

NG: Repair or replace malfunctioning part.
CHECK INTAKE AIR LEAKAGE
Listen for an intake air leakage after the mass air flow sensor.

OK or NG

OK: GO TO 4.

NG: Repair or replace malfunctioning part.

CHECK IGNITION TIMING

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

ITEM SPECIFICATIONS

Items	Specifications
Target idle speed	650 ± 50 RPM (in P or N position)
Ignition timing	12 ± 5°BTDC (in P or N position)

OK or NG

OK: GO TO 5.

NG: Follow the instructions on "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, 44, 63 and ground with CONSULT-III or tester.
Refer to WIRING DIAGRAM for fuel injectors, "WIRING DIAGRAM ".

Battery voltage should exist .

OK or NG

OK: GO TO 6.

NG: Perform "DIAGNOSIS PROCEDURE ".

Fig 2: Checking Voltage Between ECM Terminals And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
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 (1) in IPDM E/R (2) 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.
  
  Fig 3: Identifying Fuel Pump Fuse In IPDM E/R
  Courtesy of NISSAN MOTOR CO., U.S.A.
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 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 each other. Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20 kV or more.
- It might damage the ignition coil if the gap of more than 17 mm is made.
Fig 4: Identifying Gap Between Edge Of Spark Plug And Grounded Metal Portion
Courtesy of NISSAN MOTOR CO., U.S.A.

NOTE: When the gap is less than 13 mm, 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 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 .

OK or NG

OK: GO TO 8.

NG: Check ignition coil, power transistor and their circuits. Refer to "DIAGNOSIS PROCEDURE ".
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.

OK or NG

OK: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "STANDARD AND LIMIT ".

NG:
1. Repair or clean spark plug.
2. GO TO 9.
Fig 5: Checking Initial Spark Plug For Fouling
Courtesy of NISSAN MOTOR CO., U.S.A.
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 .

OK or NG

OK: INSPECTION END

NG: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "STANDARD AND LIMIT ".
CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel tube assembly.
  Refer to "COMPONENT ".
  
  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.
Check that 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 "DIAGNOSIS PROCEDURE ".

Trouble is fixed.: INSPECTION END

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