5B.19
Section 5B
EFI Fuel System
Service
The fuel pumps are non-serviceable and must be
replaced if determined to be faulty. If a fuel delivery
problem is suspected, make certain the pump is being
activated through the relay, all electrical connections
are properly secured, the fuses are good, and a
minimum of 7.0 volts is being supplied. If during
cranking, voltage drops below 7.0 volts, a reduction of
fuel pressure may occur resulting in a lean starting
condition. If required, testing of the fuel pump and
relay may be conducted.
1. Connect the black hose of Kohler pressure tester
(SPX Part No. KO3217-4) to the test valve in the
fuel rail. Route the clear hose into a portable
gasoline container or the equipment fuel tank.
2. Turn on the key switch to activate the pump and
check the system pressure on the gauge. If
system pressure of 39 psi ± 3 is observed, the
relay, fuel pump, and regulator are working
properly. Turn key switch off and depress the
valve button on the tester to relieve the system
pressure.
a. If the pressure is too high, and the regulator
is outside the tank (just down line from the
pump), check that the return line from the
regulator to the tank is not kinked or
blocked. If the return line is good, replace
the regulator (see ‘‘Regulator Service’’ on
page 5B.20).
b. If the pressure is too low, install in-line ‘‘T’’
(SPX Part No.
KO3217-8
) between the pump
and the regulator and retest the pressure at
that point. If it is too low there also, replace
the fuel pump.
3. If the pump did not activate (step 2), disconnect
the plug from the fuel pump. Connect a DC
voltmeter across the terminals in the plug, turn on
the key switch and observe if a minimum of 7
volts is present. 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 and relay as covered in the
‘‘Electrical Relay’’ section.
Figure 5B-24. External Fuel Pressure Regulators.
Figure 5B-25. Internal Fuel Pressure Regulators.
4. 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 1 and 2 to
verify correct pressure.
b. If the pump still does not operate, replace it.
Fuel Pressure Regulator
Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
www.mymowerparts.com
