Spark Plugs; Battery Charging System; Fuel Components Fuel Pump - Kohler Command PRO ECH630 Service Manual

Section 5
EFI Fuel System
2) Connect an ohmmeter set on the Rx1 scale
to the primary terminals of the coil.
Primary resistance should be 0.5-0.8 .
3) Connect an ohmmeter set on the Rx10K
scale between the spark plug boot terminal
and the B+ primary terminal. Secondary
resistance should be 6400-7800 .
4) If the secondary resistance is not within the
specifi ed range, the coil is faulty and needs
to be replaced.
NOTE: If the ignition coil(s) are disabled and an
ignition fault is registered, the system will
automatically disable the corresponding
fuel injector drive signal. The fault must be
corrected to the ignition coil and the ECU
power (switch) must be turned OFF for 10
seconds for the injector signal to return. This
is a safety measure to prevent bore washing
and oil dilution.

Spark Plugs

EFI engines are equipped with Champion
resistor spark plugs. Equivalent alternate brand
plugs can also be used, but must be resistor plugs or
permanent damage to the ECU will occur, in addition
to aff ecting operation. Proper spark plug gap is
0.76 mm (0.030 in.).

Battery Charging System

EFI engines are equipped with either a 20 or 25 amp
charging system to accommodate the combined
electrical demands of the ignition system and the
specifi c application. Charging system troubleshooting
information is provided in Section 7.
5.20
Fuel Components
Fuel Pump
General
An electric fuel pump module and a lift pump (two
types) are used to transfer fuel in the EFI system. See
Figures 5-17 and 5-18. The two types of lift pumps are
a pulse fuel pump and a mechanical fuel pump. The
pumping action is created by either the oscillation of
positive and negative pressures within the crankcase
through a hose, or by direct lever/pump actuation off
rocker arm movement. The pumping action causes
the diaphragm on the inside of the pump to pull fuel
in on its downward stroke and to push it into the fuel
pump module on its upward stroke. Internal check
valves prevent fuel from going backward through the
pump. The fuel pump module receives the fuel from
the lift pump, increases and regulates the pressure for
the fuel injectors.
® RC12YC
Figure 5-17. Fuel Pump Module.