Isuzu 2008MY N Series Workshop Manual page 372

Checks
Fuel System Checks
Air Intake System Checks
Exhaust System Checks
Inspect the fuel system problem. Refer to Fuel System Check chart and
appropriate procedure in Section 1D Engine Fuel.
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.
• Modified air induction system.
• A restriction or damaged or any contamination or objects that block at MAF
sensor.
• A worn or damaged turbocharger turbine wheel, shaft or compressor wheel.
Refer to Turbocharger Assembly in Section 1J Induction.
Inspect the exhaust system for the following conditions. Refer to Exhaust
System in Section 1G Engine Exhaust.
• An exhaust system gasket that is missing or damaged.
• Exhaust gas leakage from the exhaust pipe, gasket, DPD assembly,
exhaust temperature sensor(s) or exhaust differential pressure hoses or
pipes.
• Modified exhaust system.
• Exhaust throttle valve or exhaust brake valve for stuck condition. Refer to
Exhaust System in Section 1G Engine Exhaust.
• An excessive ash accumulation in the DPD filter.
• DPD filter for damage, cracks, melt or excessive deposits.
• Oxygen catalyst for damage, cracks, melt or excessive deposits.
• If an excessive white smoke is present while regeneration process, a
deteriorated or damaged oxygen catalyst is suspected.
Engine Control System (4HK1)
Action
1A-369