Diagnosis Procedure

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
   Fig 1: Identifying Exhaust Gas Leak Area

   

Is exhaust gas leak detected?

YES: Repair or replace.

NO: GO TO 2.

1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.

Intake air leak detected?

YES: Repair or replace.

NO: GO TO 3.

1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
   TERMINALS CONTINUITY REFERENCE
   
   

   A/F sensor 1		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F27	1	F8	45	Existed
   	2		49

5. Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.
   TERMINALS CONTINUITY REFERENCE
   
   

   A/F sensor 1		ECM		Ground	Continuity
   Connector	Terminal	Connector	Terminal
   F27	1	F8	45	Ground	Not existed
   	2		49

6. Also check harness for short to power.

Is the inspection result normal?

YES: GO TO 4.

NO: Repair open circuit or short to ground or short to power in harness or connectors.

1. Release fuel pressure to zero. Refer to "INSPECTION ".
2. Install fuel pressure gauge and check fuel pressure. Refer to "INSPECTION ".

   At idling: Approximately 350 kPa (3.57 kg/cm ²  , 51 psi) 

Is the inspection result normal?

YES: GO TO  6.

NO: GO TO 5.

Check fuel hoses and fuel tubes for clogging.

Is the inspection result normal?

YES: Replace "fuel filter and fuel pump assembly".

NO: Repair or replace

With CONSULT-III 

1. Install all removed parts.
2. Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT-III.

   1.0 - 4.0 g.m/sec: at idling 

   4.0 - 10.0 g.m/sec: at 2,500 rpm 

With GST 

1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.

   1.0 - 4.0 g.m/sec: at idling 

   4.0 - 10.0 g.m/sec: at 2,500 rpm 

Is the measurement value within the specification?

YES: GO TO 7.

NO: Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to "DTC LOGIC ".

With CONSULT-III 

1. Start engine.
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT-III 

1. Let engine idle.
2. Listen to each fuel injector operating sound.

   Clicking noise should be heard. 

Is the inspection result normal?

YES: GO TO 8.

NO: Perform trouble diagnosis for FUEL INJECTOR, refer to "COMPONENT FUNCTION CHECK ".

Fig 2: Checking Fuel Injector Operating Sound

1. Turn ignition switch OFF.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Remove fuel tube assembly. Refer to "REMOVAL AND INSTALLATION ".

   Keep fuel hose and all fuel injectors connected to fuel tube.

5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each fuel injector.
7. Crank engine for about 3 seconds.

   Fuel should be sprayed evenly for each fuel injector. 

Is the inspection result normal?

YES: GO TO 9.

NO: Replace fuel injectors from which fuel does not spray out. Always replace O-ring with new ones.

Fig 3: Checking Fuel Injector Spray

Refer to "INTERMITTENT INCIDENT ".

INSPECTION END