Operation and maintenance manual

QSB4.5 and QSB6.7 Troubleshooting Symptoms Charts
Section TS - Troubleshooting Symptoms Page TS-21
Engine Difficult to Start or Will Not Start (Exhaust Smoke)
Cause Correction
STEP 10
Vehicle parasitics are excessive
.............
Check the vehicle for brakes dragging,
transmission malfunction, cooling fan operation
cycle time, and engine-driven units. Refer to the
OEM service manual.
OK
Go To Next Step
STEP 11
Fuel leak
.............
Check the fuel lines, fuel connections, and fuel
filters for leaks. Check the fuel lines to the supply
tanks. Refer to the OEM service manual.
OK
Go To Next Step
STEP 12
Air in the fuel system
.............
Check for air in the fuel system. Tighten or replace
the fuel connections, fuel lines, fuel tank
standpipe, and fuel filters as necessary.
OK
Go To Next Step
STEP 13
Air intake system restriction is above specification
.............
Check the air intake system for restrictions. Clean
or replace the air filter and inlet piping as
necessary. Refer to Section 4.
OK
Go To Next Step
STEP 14
Fuel grade is not correct for the application or the
fuel quality is poor
.............
Operate the engine from a tank of known high
quality fuel. Refer to Fuel Recommendations and
Specifications in Section V.
OK
Go To Next Step
STEP 15
Fuel filter or fuel suction line is restricted
.............
Replace the fuel filter. Check the fuel suction line
for restriction. Refer to Section 5.
OK
Go To Next Step
STEP 16
Fuel supply is not adequate
.............
Check the flow through the filter to locate the
source of the restriction. Refer to Section 5.
OK
Go To Next Step
STEP 17
Contact a Cummins® Authorized Repair Facility