Fuel System Operation and Tests
IMPORTANT: Many machines have hydraulic pumps
that have adequate flow to load engine
well below rated load rpm. Some
equipment may need to be driven in
high gear or pull a load to bring engine
speed to rated load rpm.
8. Run engine at wide open throttle (WOT) and load
engine down gradually to rated speed rpm.
9. Record engine speed (rpm) and timing degrees.
10. Compare recorded speeds and timing degrees to
charts earlier in this group for OEM applications or
refer to machine technical manual.
IMPORTANT: Stop engine prior to making timing
adjustments. Injection pump can seize if
adjustment is made with engine
11. Stop engine.
If dynamic timing reading is more than 8 degrees retarded
with pump flange and front plate timing marks at original
location as shipped from factory, this may indicate the
pump advance is not functioning. Check the following:
· Change fuel filter(s).
· Check transfer pump for positive fuel pressure to
· Check camshaft movement on injection pumps with
rectangular timing window.
· Check pump drive shaft-to-gear key or pin to ensure
key or pin has not sheared.
· If none of the above checks are conclusive, remove
pump and have necessary repairs made at an
authorized diesel repair station.
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