DETROIT DIESEL 53
Trouble Shooting Engine 15.2
Chart 1 (Cont'd. )
EXHAUST SMOKE ANALYSIS
Replace faulty injectors if this condition still persists
1. High exhaust back pressure or a restricted air inlet
after timing the injectors and performing the engine
causes insufficient air for combustion and will result in
incompletely burned fuel.
Lugging the engine will cause incomplete combustion
High exhaust back pressure is caused by faulty exhaust
and should be avoided. Operate the engine as outlined
piping or muffler obstruction and is measured at the
in the Drivers Handbook.
exhaust manifold outlet with a manometer.
causing high exhaust back pressure should be replaced.
3. Check for the use of an improper grade of fuel.
Restricted air inlet to the engine cylinders is caused by
Consult the Fuel Oil Specifications for the correct fuel tot
clogged cylinder liner ports, air cleaner, or blower air
inlet screen. These items should be cleaned. Check
the emergency stop to make sure that it is completely
4. Check for internal lubricating oil leaks, and refer to
open and readjust it if necessary.
the High Lubricating Oil Consumption chart.
2. Check for improperly timed injectors and improperly
5. Check for faulty injectors and replace as necessary.
positioned injector rack control levers. Time the fuel
Check for low compression and consult the Hard
injectors as outlined in Fuel Injector Timing and perform
the appropriate governor tune-up to correct this
The use of low cetane fuel will cause this condition and
can be corrected by consulting and following the Fuel Oil
1970 General Motors Corp.
SEC. 15.2 Page 5