Isuzu 2008MY N Series, Руководство по ремонту

Страница: 353 / 404

1A-350 Engine Control System (4HK1)
Fuel System Checks Inspect the fuel system for the following conditions. Refer to Fuel System
Check chart and appropriate procedure in Section 1D Engine Fuel.
• Air in the fuel system.
• Water contamination in the fuel.
• Fuel waxing or icing.
• Fuel filter clogging.
• External fuel leaks or high engine oil level.
• Fuel leak off from the fuel pressure limiter valve and fuel injectors.
• Fuel lines between the fuel tank and fuel supply pump for being crushed,
kinked, tightness, cracks and plugged.
• A plugged fuel tank vent hose.
• Inside the fuel tank for any foreign material that may be getting drawn into
the fuel line pickup causing a blocked condition.
• Fuel supply pump operation.
Notice: The fuel supply pump must be timed to the engine and adjustment
value must be learned to the ECM.
• Perform the Cylinder Balance Test with a scan tool.
• Perform the Injector Force Drive with a scan tool.
• Observe the Fuel Compensation for each cylinder at idle on the scan tool.
• Observe the FRP Regulator Feedback current on the scan tool.
Air Intake System 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.
Exhaust System Checks Inspect the exhaust system for a possible restriction. Refer to Exhaust System
in Section 1G Engine Exhaust.
Engine Mechanical Checks Inspect the engine mechanical for the following conditions. Refer to the
Section 1B Engine Mechanical.
• Poor cylinder compression.
• Improper mechanical timing (timing gear).
• Improper valve gap.
• Broken or weak valve springs.
• Worn camshaft lobes.
• Incorrect basic engine parts such as camshaft, cylinder head, pistons, etc.
Checks Action
LG4HKED-WE-0871.book 350 ページ ２００７年１１月２９日 木曜日 午後６時２９分