EXHAUST SMOKE ANALYSIS
injectors and perform the appropriate governor tune-up.
1. High exhaust back pressure or a restricted air inlet
causes insufficient air for combustion and will result in
Replace faulty injectors if this condition still persists
incompletely burned fuel.
after timing the injectors and performing the engine
Avoid lugging the engine as this will cause incomplete
High exhaust back pressure is caused by faulty exhaust
piping or muffler obstruction and is measured at the
exhaust manifold outlet with a manometer. Replace
2. Check for use of an improper grade of fuel. Refer to
3. Check for internal lubricating oil leaks and refer to
Restricted air inlet to the engine cylinders is caused by
the High Lubricating Oil Consumption chart.
clogged cylinder liner ports, air cleaner or blower air
inlet screen. Clean these items. Check the emergency
4. Check for faulty injectors and replace as necessary.
stop to make sure that it is completely open and readjust
it if necessary.
Check for low compression and consult the Hard
The use of low cetane fuel will cause this condition.
Check for improperly timed injectors and improperly
positioned injector rack control levers. Time the fuel