TROUBLESHOOTING
14-7
1.6 Idling malfunction
1.6.1 Check items before troubleshooting
(1) Engine control system malfunction
(2) Viscosity of engine oil too high
(3) Use of poor quality fuel
1.6.2 Problem: Unstable idling
Problem: Unstable idling
YES
YES
YES
NO
NO
NO
Adjust engine
Inspect fuel injection nozzles
Inspect valves, pistons and piston rings
Inspect fuel injection pump and governor system
Is the engine correctly adjusted
(engine idle speed, valve clearance and
fuel injection timing)?
Are fuel injection nozzles normal (spray state,
injection-valve opening pressure too high)?
Is the compression
pressure normal?