Exhaust Smoke Is Black (Incomplete Combustion) - Komatsu PC130-7 Shop Manual

TROUBLESHOOTING
S-7 Exhaust smoke is black
(Incomplete combustion)
General causes why exhaust smoke is black
• Insufficient intake of air
• Improper condition of fuel injection
• Excessive injection of fuel
Confirm recent repair history
Degree of use of machine
Color of exhaust gas
Engine oil must be added more frequently
Power was lost
Non-specified fuel is being used
Noise of interference is heard from around turbocharger
Dust indicator lamp is red
Blow-by gas is excessive
Engine pickup is poor and combustion is irregular
When exhaust manifold is touched immediately after
starting engine, temperature of some cylinders is low
Timing lock on fuel injection pump does not match
Seal on injection pump has come off
Clanging sound is heard from around cylinder head
Exhaust noise is abnormal
Muffler is crushed
Leakage of air between turbocharger and head, loose clamp
When turbocharger is rotated by hand, it is found to be heavy
When air cleaner element is inspected directly, it is found to be
clogged
When compression pressure is measured, it is found to be low
Speed does not change when operation of certain cylinders
is stopped
When check is made using delivery method, injection timing
is found to be incorrect
Injection pump test shows that injection amount is incorrect
When valve clearance is checked directly it is found to be
outside standard value
When muffler is removed, exhaust color returns to normal
When control rack is pushed, it is found to be heavy, or
does not return
PC130-7
Operated for long period
Suddenly became black
Gradually became black
Blue under light load
Suddenly
Gradually
Remedy
Causes
20-615
S-7
(1)