Kohler LH630-775 Service Manual page 54

Section 5B
EFI Fuel System
2. Make sure all safety switch requirements are
met. Crank the engine and check for flashing of
noid light. Repeat test at other connector.
a. If flashing occurs, use an ohmmeter (Rx1
scale) and check the resistance of each injector
across the two terminals. Proper resistance is
12-20 Ω Ω Ω Ω Ω . If injector resistance is correct, check
whether the connector and injector terminals
are making a good connection. If the
resistance is not correct, replace the injector
following steps 1-8 and 13-16 below.
b. If no flashing occurs, reattach connectors to
both injectors. Disconnect the main harness
connector from the ECU and the connector
from the relay. Set the ohmmeter to the Rx1
scale and check the injector circuit resistance
as follows: Check the resistance between relay
terminal #87 and pin #14 in the main
connector. Then check the resistance between
relay terminal #87 and pin #15. Resistance
should be 4-15 Ω Ω Ω Ω Ω for each circuit.
Check all electrical connections, connectors,
and wiring harness leads if resistance is
incorrect.
Injector leakage is very unlikely, but in those rare
instances it can be internal (past the tip of the valve
needle), or external (weeping around the injector
body). See Figure 5B-17. The loss of system pressure
from the leakage can cause hot restart problems and
longer cranking times. To check for leakage it will be
necessary to remove the blower housing, which may
involve removing the engine from the unit.
Figure 5B-17. Injector Inspection Points.
5B.14
Check For Leaks
1. Engine must be cool. Depressurize fuel system
through the test valve in fuel rail.
2. Disconnect the spark plug leads from spark
plugs.
3. Remove the air cleaner outer cover, inner wing
nut, element cover and air cleaner element/
precleaner. Service the air cleaner components as
required.
4. Remove the two screws securing the air cleaner
base to throttle body manifold. Remove the air
cleaner base to permit access to the injectors.
Check condition of air cleaner base gasket,
replace if necessary.
5. Remove the flywheel screen if it overlaps the
blower housing.
6. If the engine has a radiator-type oil cooler
mounted to the blower housing, remove the two
oil cooler mounting screws.
7. Remove the blower housing mounting screws.
Note the location of the plated (silver) screw
attaching the rectifier/regulator ground lead.
Remove the blower housing.
8. Thoroughly clean the area around and including
the throttle body/manifold and the injectors.
9. Disconnect the throttle linkage and damper
spring from the throttle lever. Disconnect the TPS
lead from the harness.
10. Remove the manifold mounting bolts and
separate the throttle body/manifold from the
engine leaving the TPS, fuel rail, air baffle,
injectors and line connections intact. Discard the
old gaskets.
11. Position the manifold assembly over an
appropriate container and turn the key switch
"on" to activate the fuel pump and pressurize
the system. Do not turn switch to "start"
position.
12. If either injector exhibits leakage of more than
two to four drops per minute from the tip, or
shows any sign of leakage around the outer shell,
turn the ignition switch off and replace injector
as follows.