Kohler Command PRO ECV630 Service Manual page 58

EFI SYSTEM-BOSCH
12. If either injector exhibits leakage of more than two to
four drops per minute from tip, or shows any sign of
leakage around outer shell, turn ignition switch off
and replace injector as follows.
13. Depressurize fuel system following procedure in fuel
warning on page. Remove fuel rail mounting screws.
14. Clean any dirt accumulation from sealing/mounting
area of faulty injector(s) and disconnect electrical
connector(s).
15. Pull retaining clip off top of injector(s). Disconnect
fuel rail and remove injector(s) from manifold.
16. Reverse appropriate procedures to install new
injector(s) and reassemble engine. Use new
O-Rings any time an injector is removed (new
replacement injectors include new O-Rings).
Lubricate O-Rings lightly with oil. Torque fuel rail and
blower housing mounting screws to 3.9 N·m (35 in.
lb.), and intake manifold and air cleaner mounting
screws to 9.9 N·m (88 in. lb.).
Injector problems due to dirt or clogging are generally
unlikely due to design of injectors, high fuel pressure,
and detergent additives in gasoline. Symptoms that
could be caused by dirty/clogged injectors include rough
idle, hesitation/stumble during acceleration, or triggering
of fault codes related to fuel delivery. Injector clogging
is usually caused by a buildup of deposits on director
plate, restricting flow of fuel, resulting in a poor spray
pattern. Some contributing factors to injector clogging
include higher than normal operating temperatures, short
operating intervals, and dirty, incorrect, or poor quality
fuel. Cleaning of clogged injectors is not recommended;
they should be replaced. Additives and higher grades of
fuel can be used as a preventative measure if clogging
has been a problem.
NOTE: Do not ground coils with ignition ON, as they
may overheat or spark.
Testing
1. Disconnect main harness connector from ECU.
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Locate
pins #22 and #23 in 24 pin connector. See page .
"32 Pin" (MSE 1.1) Plastic Cased ECU: Locate
pins #30 and #31 in 32 pin connector. See page.
2. Disconnect connector from relay and locate terminal
#87 in connector.
3. Using an ohmmeter set on Rx1 scale, check
resistance in circuits as follows:
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Check
between terminal #87 and pin #22 for coil #1.
Repeat test between terminal #87 and pin #23 for
coil #2.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Check
between terminal #87 and pin #30 for coil #1.
Repeat test between terminal #87 and pin #31 for
coil #2.
A reading of 1.8-4.0 Ω in each test indicates that
wiring and coil primary circuits are OK.
a. If reading(s) are not within specified range, check
and clean connections and retest.
58
b. If reading(s) are still not within specified range,
test coils separately from main harness as
follows:
1. Disconnect red and black primary leads from
coil terminals.
2. Connect an ohmmeter set on Rx1 scale to
primary terminals. Primary resistance should
be 1.8-2.5 Ω.
3. Disconnect secondary lead from spark plug.
Connect an ohmmeter set on Rx10K scale
between spark plug boot terminal and red
primary terminal. Secondary resistance should
be 13,000-17,500 Ω.
4. If secondary resistance is not within specified
range, unscrew spark plug lead nut from coil
secondary tower and remove plug lead.
Repeat step b. 3, testing from secondary
tower terminal to red primary terminal. If
resistance is now correct, coil is good, but
spark plug lead is faulty, replace lead. If step
b. 2 resistance was incorrect and/or
secondary resistance is still incorrect, coil is
faulty and needs to be replaced.
Wiring harness used in EFI system connects electrical
components, providing current and ground paths for
system to operate. All input and output signaling occurs
through a special all weather connector that attaches
and locks to ECU.
Condition of wiring, connectors, and terminal
connections is essential to system function and
performance. Corrosion, moisture, and poor connections
are more likely cause of operating problems and system
errors than an actual component.
Fuel Pump
Fuel pumps are non-serviceable and must be replaced
if determined to be faulty. If a fuel delivery problem
is suspected, make certain pump is being activated
through relay, all electrical connections are properly
secured, 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
fuel pump and relay may be conducted.
1. Connect black hose of Pressure Tester (part of EFI
Service Kit, see Tools and Aids) to test valve in fuel
rail. Route clear hose into a portable gasoline
container or equipment fuel tank.
2. Turn on key switch to activate pump and check
system pressure on gauge. If system pressure of 39
psi ± 3 is observed, relay, fuel pump, and regulator
are working properly. Turn key switch off and
depress valve button on tester to relieve system
pressure.
a. If pressure is too high, and regulator is outside
tank (just down line from pump), check that return
line from regulator to tank is not kinked or
blocked. If return line is good, replace regulator
(see Regulator on page).
KohlerEngines.com 24 690 02 Rev. D