Troubleshooting

RENR2696-01 43
Troubleshooting Section
Low Compression
1. Remove the fuel injectors and perform a
compression test. Refer to Systems Operations,
Testing and Ad
justing, “Compression - Test ”data.
Examples of low compression are shown in the
following lis
t:
•
Outside temperatures are too cold.
•
Mechanical problem
•
Faulty piston
rings
•
Worn cylinder bores
•
Worn valves
•
Faulty cylind
er head gasket
•
Damaged cylinder head
2. Make all necessary repairs to the engine.
3. Ensure that th
e repairs have eliminated the active
diagnostic code.
4. If the engine
will not start proceed to “Fuel Supply”.
Fuel Supply
1. Check the fuel pressure. Refer to Systems
Operation, Testing and Adjusting, “Fuel System
Pressure - Te
st”.
2. Ensure that the fuel system has been primed.
Refer to Sys
tems Operation, Testing and
Adjusting, “Fuel System - Prime”.
3. Check the di
esel fuel for contamination. Refer to
Systems Operation, Testing and Adjusting, “Fuel
Quality - Test”.
4. Check for air in the fuel system. Refer to Systems
Operation, Testing and Adjusting, “Air in Fuel -
Test” .
5. Check that the fuel lines are tight and secured
properly.
6. Check for fuel supply lines that are restricted.
7. Check the fuel filters.
8. Visually c
heck the fuel tank for fuel. The fuel
gauge may be faulty.
9. If the engi
ne has a water separator, check for
water in the fuel.
10. Ensure tha
t the fuel supply valve (if equipped) is
in the full OPEN position.
11. If the temperature is below 0 °C (32 °F), check
for solidified
fuel (wax).
12. Check the fuel injection pump. Refer to
Troubleshoot
ing, “Fuel Injection Pump Circuit -
Te s t ” .
i01798120
Engine Has Early Wear
Probable Caus
es
•
Dirt in engine oil
•
Leaks in air intake system
•
Low oil pressu
re
Recommended
Actions
Dirt in Engine Oil
1. Drain the oil from the crankcase and refill the
crankcase with clean engine oil. Install new engine
oil filters.
Refer to the Operation and Maintenance
Manual for more information.
2. Check the oil
filter bypass valve for a weak
spring or a broken spring. If the spring is weak or
broken, replace the spring. Refer to Disassembly
and Assembl
y, “Engine Oil Filter Base” for more
information.
Leaks in Air
Intake System
A leak in the air intake system may allow unfiltered
air into the
engine. Inspect the air intake system for
leaks. Inspect all of the gaskets and the connections.
Repair any leaks. Refer to Testing and Adjusting, “Air
Intake Sys
tem” for more information.
Low Oil Pressure
Refer to Troubleshooting, “Low Engine Oil Pressure”
for the testing procedure. Repair any identified faults.
i01798121
Engine Misfires, Runs Rough
or Is Unstable
The probable root causes are listed in order below: