Throttle Body/Intake Manifold Assembly; Idle Speed Adjustment (Rpm) - Kohler COMMAND CV17-745 Service Manual

Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
Section 5B
EFI Fuel System
General
High-pressure fuel line with an SAE 30 R9 rating is
required for safe and reliable operation, due to the
higher operating pressure of the EFI system. If hose
replacement is necessary, order fuel line service kit
24 353 42-S (containing 60" of high-pressure hose and
10 Oetiker clamps), or use only the type of hose
specified. Special Oetiker clamps (Kohler Part No.
24 237 05-S) are used on all fuel line connections to
prevent tampering and safety hazards with the high
fuel pressure. The old clamp must be cut to open a
connection, so replacement is necessary each time.
Oetiker clamp pliers (SPX Part No. KO3217-5) must
be used to crimp the replacement clamps.
CAUTION: Fuel lines between the fuel pump
and fuel rail must be made from SAE 30 R9 fuel line.
Standard fuel line (SAE 30 R7) may only be used
between the fuel tank and pump (5/16" ID) and for the
return line from the pressure regulator to the tank (1/4"
ID). All high-pressure fuel line connections must be
secured with Oetiker clamps (Kohler Part No.
24 237 05-S), installed/crimped with the corresponding
pliers.

Throttle Body/Intake Manifold Assembly

Figure 5B-32. Upper Throttle Body/Intake Manifold
Details.
General
The EFI engines have no carburetor, so the throttle
function (regulate incoming combustion airflow) is
incorporated in the intake manifold assembly. The
manifold consists of a one-piece aluminum casting
which also provides mounting for the fuel injectors,
throttle position sensor, fuel rail, air baffle, idle speed
screw, and air cleaner assembly.
5B.22
Service
The throttle body/intake manifold is serviced as an
assembly, with the throttle shaft, TPS, throttle plates,
and idle speed adjusting screw installed. The throttle
shaft rotates on needle bearings (non-serviceable),
capped with rubber seals to prevent air leaks. A throttle
shaft repair kit is available to replace the shaft if worn
or damaged. The appropriate "TPS Initialization
Procedure" must be performed after any throttle shaft
service.

Idle Speed Adjustment (RPM)

General
The idle speed is the only adjustment that may be
performed on the EFI system. The standard idle speed
setting for EFI engines is 1500 RPM, but certain
applications might require a different setting. Check
the equipment manufacturer's recommendation.
For starting and warm up, the ECU will adjust the fuel
and ignition timing, based upon ambient temperature,
engine temperature, and loads present. In cold
conditions, the idle speed will probably be higher than
normal for a few moments. Under other conditions, the
idle speed may actually start lower than normal, but
gradually increase to the established setting as
operation continues. Do not attempt to circumvent this
warm up period, or readjust the idle speed during this
time. The engine must be completely warmed up, in
closed loop operating mode for accurate idle
adjustment.
Adjustment Procedure
1. Make sure there are no fault codes present in the
ECU memory.
2. Start the engine and allow it to fully warm up and
establish closed looped operation (approximately
5-10 min.).
3. Place the throttle control in the ''idle/slow'' position
and check the idle speed with a tachometer. Turn
the idle speed screw in or out as required to
obtain 1500 RPM, or the idle speed specified by
the equipment manufacturer. See Figure 5B-33.
4. The idle speed adjustment can affect the high idle
speed setting. Move the throttle control to the full
throttle position and check the high idle speed.
Adjust as necessary to 3750 RPM, or the speed
specified by the equipment manufacturer.
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