Kohler Command PRO CH749, Service Manual

Page: 54 / 154

5.22
Section 5
EFI Fuel System
Figure 5-20. High Pressure Fuel Line with Fuel
Injectors.
General
The high pressure fuel line is an assembly of hoses,
injector caps and a fuel connector to the fuel pump
module. The high pressure fuel line feeds fuel to the
top of the injectors through the injector caps. The caps
are fastened to the intake manifold and the injectors
are locked into place. A small retaining clip provides a
secondary lock.
The high pressure fuel line is serviced as a complete
assembly to prevent tampering and safety hazards.
The components are not individually serviceable.
These engines use low permeation rated fuel lines,
certified to comply with California and U.S. EPA
evaporative emission requirements. Fuel lines that do
not meet these requirements may not be used. Order
replacement hose through a Kohler Service Center.
CAUTION:
Low permeation high-pressure fuel line with an SAE 30R9
or 30R12 rating (1/4 in. I.D.) is required for safe and
reliable operation due to higher operating pressure of the
EFI system. Low permeation low-pressure fuel line with a
SAE 30R7 rating (1/4 in. I.D.) may only be used between
the fuel tank and lift pump, between the lift pump and fuel
pump module, or as otherwise configured in the application.
6. If voltage is between 7 and 14, turn key switch
OFF and connect an ohmmeter between the
terminals on the pump to check for continuity.
a. If there was no continuity between the pump
terminals, replace the fuel pump.
b. If the voltage was below 7, test the wiring
harness.
7. If voltage at the plug was good, and there was
continuity across the pump terminals, reconnect
the plug to the pump, making sure you have a
good connection. Turn on the key switch and
listen for the pump to activate.
a. If the pump starts, repeat steps 2 and 3 to
verify correct pressure.
b. If the pump still does not operate, replace it.
NOTE: The fuel pump module pins are coated with
a thin layer of electrical grease to prevent
fretting and corrosion. Do not attempt to
remove electrical grease from the fuel pump
module pins.
Fuel Filter
Figure 5-19. In-Line Fuel Filter.
General
The precision components inside the fuel pump
module are not serviceable. DO NOT attempt to open
the fuel pump module. Damage to the components
will result and the warranty will be void. Because
the fuel pump module is not serviceable, the engines
are equipped with a special 10-micron EFI fuel filter
to prevent harmful contamination from entering the
module. See Figure 5-19.
If there are two filters in the system, the one before
the lift pump will be a standard 51-75 micron filter,
and the one after the lift pump will be the special
10-micron filter. Be sure to use an approved 10-micron
filter for replacement.
Service
Periodically inspect the filter and replace
every 200
operating hours or more frequently under extremely
dusty or dirty conditions. Use only a genuine Kohler
filter and install it according to the directional arrows.
Failure to use the proper filter can result in engine
damage and void the warranty.
High Pressure Fuel Line