Isuzu 2008MY N Series Workshop Manual page 359

1A-356 Engine Control System (4HK1)
Checks
Air Intake System Checks
Exhaust System Checks
Additional Checks
Inspect the air intake system for the following conditions.
• Air cleaner, air intake ducts and charge air cooler for a restriction, holes, or
leaks.
• A restriction in the turbocharger inlet duct.
• Intake throttle valve for a stuck condition.
• A restriction or leak in the intake manifold.
• Turbocharger nozzle control solenoid for a stuck condition. Refer to
Turbocharger Assembly in Section 1J Induction.
Inspect the exhaust system for a possible restriction. Refer to Exhaust System
in Section 1G Engine Exhaust.
• Inspect the EGR system operating correctly. Refer to EGR Control System
Check in this section.
• Inspect the A/C operation.
• Inspect the lock up clutch operation. (Smoother only)
• Inspect deformed tire(s) that may cause surges at fixed vehicle speed
range.
Action