Isuzu 2008MY N Series, Руководство по ремонту

Страница: 369 / 404

1A-366 Engine Control System (4HK1)
Excessive Smoke (White Smoke)
Checks Action
Difinition:
White smoke under load, idle or start up hot or cold.
Preliminary Check • Ensure the vehicle has an actual problem.
• Inspect the ECM grounds for being clean, tight, and in their proper
locations.
• Inspect the fuel quality (cetane index).
• Inspect the programmed fuel injector ID code for each cylinder.
• Inspect the Scan Tool Data List in this section.
• Inspect the Service Bulletin.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the
Scan Tool Data List in this section.
• Compare the Coolant Temperature with the Intake Air Temperature (IAT)
and Fuel Temperature (FT) parameters on a cold engine condition. If the
difference among temperature reading is more than 5
°
C (9
°
F) on a cold
engine, check for high resistance in each circuit or for a skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT may
indicate a higher than normal intake air temperature if the ignition switch is
being ON.
• Observe the Fuel Rail Pressure (FRP) Sensor parameter with the engine
OFF. The FRP Sensor should read 0.9 to 1.0 volt with the ignition switch ON
and engine OFF after the engine has stopped running for a minimum of 1
minute. If not, check for high resistance in each circuit or for a skewed
sensor.
• Observe the Fuel Rail Pressure and Desired Fuel Rail Pressure parameter
between idle and W.O.T. (accelerator pedal full travel) in Neutral. Fuel Rail
Pressure parameter should follow within
±
5 MPa (
±
725 psi) quick enough.
• Observe the Accelerator Pedal Position (APP). APP parameter should
change linearly from 0 to 100% according to the accelerator pedal
operation.
• Observe the Boost Pressure and Barometric Pressure (BARO) with ignition
ON and engine OFF. Both parameters should be within the 7.0 kPa (1.0 psi)
each other.
• Crankshaft position (CKP) sensor is tight and the sensor rotor is not
damaged.
Fuel System Checks • If excessive smoke is present, check for a stuck open fuel injector. Inspect
for fuel leakage into the combustion chamber.
• Fuel injectors. Remove the injectors and visually inspect.
• Perform the Cylinder Balance Test with a scan tool.
• Perform the Pilot Injection Control with a scan tool.
• Observe the Fuel Compensation for each cylinder at idle on the scan tool.
LG4HKED-WE-0871.book 366 ページ ２００７年１１月２９日 木曜日 午後６時２９分