Service manual

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Service Manual Mitsubishi SL-Series diesel engines
Version 08/2004
TROUBLESHOOTING
ENGLISH
OVERHAUL INSTRUCTIONS
6.2.5 Problem 5: Erratic idle speeds
1. Items to be checked ahead of time
• Maladjusted engine control
• Wrong oil grade for weather conditions
• Poor quality fuel
2. Inspection procedure
Are valve clearance and injection timing correct? No Z
Make adjustment to the
clearance and timing.
VYes
Is injection nozzle discharge pattern normal? Is injection pressure
constant?
No Z
Make adjustment to the
nozzles.
V Yes
Is compression pressure correct (no difference in compression pressure
between cylinders)?
No Z
Check valves, piston rings
and cylinder head gasket.
V Yes
Fuel injection pump is faulty.