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Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
TROUBLESHOOTING GENERAL
6.6 Unsteady idling
6.6.1 Matters to be checked before
diagnosis
1. Faulty engine control system
2. Too high viscosity of engine oil
3. Use of poor-quality fuel
6.6.2 Diagnosis
Is engine adjusted properly?
(Check for idling speed, valve clearance, and injection timing.)
No Z Adjust engine.
V Yes
Do injection nozzles operate properly?
(Check for shape of fuel spray and injection starting pressure.)
No Z Inspect injection nozzles.
V Yes
Is cylinder compression pressure proper?
(Check equality between cylinders.)
No Z
Inspect valves, pistons and
piston rings.
V Yes
Inspect injection pump and
governor system.