Operation and maintenance manual

Troubleshooting Symptoms Charts QSB4.5 and QSB6.7
Page TS-46 Section TS - Troubleshooting Symptoms
Fuel Consumption Excessive
Cause Correction
STEP 1
Operator technique is not correct
............. Refer to Section 1, Operating Instructions.
OK
Go To Next Step
STEP 2
Electronic fault codes are active
.............
For instructions on how to read active fault codes,
refer to Section 1. If fault codes are active, contact
a Cummins Authorized Repair Facility.
OK
Go To Next Step
STEP 3
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 4
Hubometer or odometer is miscalibrated
.............
Check the hubometer and odometer calibrations.
Calibrate or replace the hubometer or odometer, if
necessary. Calculate fuel consumption with new
mileage figures.
OK
Go To Next Step
STEP 5
Hour meter is miscalibrated
.............
Check the hour meter. Calibrate or replace the
hour meter if necessary. Calculate fuel
consumption with new figures.
OK
Go To Next Step
STEP 6
Air intake or exhaust leaks
.............
Check for loose or damaged piping connections
and missing pipe plugs. Check the turbocharger
and exhaust manifold mounting. Refer to Section
3.
OK
Go To Next Step
STEP 7
Air intake system restriction is above specification
.............
Check the air intake system for restriction. Clean
or replace the air filter and inlet piping as
necessary. Refer to Section 4.
OK
Go To Next Step
STEP 8
Equipment and environmental factors are affecting
fuel consumption
.............
Consider ambient temperatures, wind, tire size,
axle alignment, routes, and use of aerodynamic
aids when evaluating fuel consumption.
OK
Go To Next Step