Engine Does Not Rev Up

SYMPTOM DESCRIPTION:

When the throttle control lever is rotated to increase engine rpm, the engine rpm only raises a little no matter what the position of the throttle control lever. The engine rpm never gets close to its maximum rpm even if the throttle control lever is rotated to wide open throttle.




POSSIBLE CAUSE ACTION

Improper fuel ^ Drain fuel tank, flush system,
and fill with proper fuel. Change
fuel filter.



Empty fuel tank or ^ Fill tank.
fuel tank vent blocked ^ Bleed fuel system.

^ Check tank vent.






Air in fuel system ^ Bleed fuel system.





Control lever not going ^ Adjust throttle linkage.
to full throttle






Intercooler internally ^ Check pressure drop across
blocked or restricted inlet and outlet of intercooler.
If pressure drop exceeds 4 in. Hg,
clean or replace intercooler as
needed.







Clogged fuel filter ^ Replace fuel filter.




Restricted or blocked fuel ^ Clean restricted lines or
supply lines. replace as needed.
Bleed fuel system.





Wax buildup in fuel filter ^ Replace fuel filter, and
(cold weather only) verify that the proper fuel is
being used.




Incorrect injection pump to ^ Adjust injection pump timing.
engine timing



Injection pump overflow fitting ^ Install fittings to their
switched with fuel inlet fitting proper locations.
Bleed fuel system.





Low or uneven engine ^ Repair as necessary.
compression







Injection pump malfunction ^ If injection pump is malfunctioning
or will not adjust properly, replace as
a unit.