Idling Malfunction; Check Items Before Troubleshooting; Problem: Unstable Idling - Mitsubishi Heavy Industries SL Series Service Manual

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

Is the engine correctly adjusted
(engine idle speed, valve clearance and
fuel injection timing)?
YES
Are fuel injection nozzles normal (spray state,
injection-valve opening pressure too high)?
YES
Is the compression
pressure normal?
YES
Inspect fuel injection pump and governor system
NO
NO
NO
Inspect valves, pistons and piston rings
Problem: Unstable idling
Adjust engine
Inspect fuel injection nozzles
TROUBLESHOOTING
14-7