Service Manual – SC8000

Engine System, LPG

Functional Description

The LPG SC8000 machines use a four-cylinder 1.6L Kubota WG1605-L-E3 engine that is liquid cooled and and naturally aspirated to power the two hydraulic pumps that run the machine drive wheel, scrub/ sweep systems, vacuum fan motor, the scrub/sweep and squeegee lift actuators and the steering system.

An E-controls Engine Management System modifies the fuel mixture based on feedback input from oxygen sensors, and also controls the electonic throttle and ignition system.

Overview

The LPG SC8000 machines use a four-cylinder 1.6L WG 1605 Kubota engine to drive two hydraulic pumps.

Note: Also refer to the following manufacturer’s technical literature for the WG 1605 Kubota Engine:

• Engine Operator’s Manual WG1605 EG523-89162ENG.pdf

• Engine Specifications WG1605 9Y110-01770.pdf

• Engine Workshop Manual WG1605 9Y111-06610.pdf

• Diagnosis Manual ECM System WG1605 9Y110-01760.pdf

94

Kubota 1.6L LPG Fuel System Description

The fuel system on LPG engines includes an LPG Fuel Lock-off device, Dual Stage Regulator (DSR), Direct

Electronic Pressure Regulator (DEPR), Mixer Assembly and Electronic Throttle Body (ETB).

An LPG Fuel Lock-off device, consisting of a 12 volt solenoid and a normally-closed valve, opens during cranking and engine run cycles. The ECM controls the voltage to the LPG Fuel Lock-off device.

The DSR is a two-stage regulator that is a combination vaporizer, pressure regulating device. The DSR is normally closed when the engine is not running. When the engine is cranking or running, a partial vacuum is created in the fuel line which connects the regulator to the DEPR and Mixer Assembly. This partial vacuum opens the second stage regulator, permitting fuel to flow to the DEPR and Mixer Assembly.

The DEPR controls the fuel flow, and provides the correct air/fuel mixture to maintain performance and emissions control. The DEPR uses an internal computer, and fuel pressure and temperature sensors to provide input to the ECM for fuel calculation, fault detection and diagnostics.

The Mixer Assembly is a self-contained air/fuel metering device that utilizes a relatively constant pressure drop to draw fuel into the mixer from cranking to full load. The Mixer Assembly is mounted in the air stream, ahead of the ETB.

The ETB uses an electric motor, connected to the throttle shaft, to increase or decrease the angle of the throttle blade. The ECM sends electrical signals to the motor in the ETB to increase or decrease the airflow to the engine to control the engine speed.

Note: For a more detailed and thorough description of the LPG fuel systems, refer to the Diagnosis

Manual ECM System WG1605 9Y110-01760.pdf.

Service Manual – SC8000 Engine System, LPG 95

Engine Start and Run Circuit Description

In between the Drive Box and the Engine system is a “Relay PCB”. It is a small printed circuit board with two relays on it. One of the relays provides power out to the engine system to turn it on (or off). The other relay provides power out to the engine starter when the key is turned to the crank position and the drive pedal is in the neutral position.

ENGINE START/RUN RELAY PCB J7

Requirements:

1. First turn the S1 Key Switch to “Start” position, then released to it’s “Run” position.

2. Foot pedal in Neutral.

DRIVE

BOX

Battery (+) From

F1 Fuse 100A & CB6 15A

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+ + + + + +

+ + + + + +

+

+

+

+

+

+

+

+

+

+

J7-8

S1

+ + + + + + + + +

J7-6

START

3

B1

IGN

+ + + + + + + + + +

K2

K3

- - -

- -

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

J7-1

+

+

+

+

+ +

K2

K3

+

+

J7-5

+

+ + + + + + +

+

+

J7-2

+

+ + + + + + +

+

+

+

+

+

+

+ + +

+

+

+

+ +

+

START COM-

MAND TO

STARTER RELAY

IGN. SW INPUT

ALT. EXCITE

PIN J1-22

PIN J1-34

START INHIBIT

J7-3

J7-7

RUN INHIBIT

RELAY

PCB

J7-4

BAT -

PIN J1-10

PIN J1-31

PIN J1-11

1

R1

2

3

DRIVE PEDAL SENSOR

BAT -

Circuit Description

• For the engine to start:

• The

Key Switch S1

must provide positive voltage to the

START

relay coil

K3

and the

IGN

relay coil

K2

.

• The

K2 RELAY CONTROL SWITCH

must be closed to provide a ground to the

IGN

relay coil

K2

. This closes the

K2

relay contacts to provide positive voltage to the

IGN. SW INPUT

. Note that if the

Driver Box

sends a

RUN INHIBIT

signal from

J1-34

to the

K2 RELAY CONTROL SWITCH

to open the switch, no ground will be provided to the

IGN

relay coil

K2

, the

K2

contacts will not close and no positive voltage will be sent to the

IGN. SW INPUT

.

• The

K3 RELAY CONTROL SWITCH

must be closed to provide a ground to the

START

relay coil

K3

. This closes the

K3

relay contacts to provide positive voltage to the

START COMMAND TO STARTER RELAY

.

Service Manual – SC8000 Engine System, LPG 96

Note that if the

Driver Box

sends a

START INHIBIT

signal from

J1-22

to the

K3 RELAY CONTROL SWITCH

to open the switch, no ground will be provided to the

START

relay coil

K3

, the

K3

contacts will not close and no positive voltage will be sent to the

START COMMAND TO STARTER RELAY

.

• The drive pedal must be in the neutral position and the

Drive Pedal Sensor

must be in the deadband range.

• For the engine to run:

• The

K2 RELAY CONTROL SWITCH

must remain closed to provide a ground to the

IGN

relay coil

K2

. This keeps the

K2

relay contacts closed to maintain positive voltage to the

IGN. SW INPUT

.

• The

Coolant Temperature Output

must not provide an “overheat” signal to pin

J1-30

on the

Driver Box

.

The engine coolant temperature sensor is a temperature-sensitive resistor. If the engine coolant temperature exceeds 225 degrees F. for more than five seconds, the Engine System senses the threshold resistance in the coolant temperature sensor. The Engine System then provides a

Coolant

Temperature Output

signal to pin

J1-30

to generate a fault code and shut the engine off.

• The

Low LP Pressure Switch S5

must be open to indicate adequate LP fuel supply (LPG engines only).

Note: LPG engines will continue to run for a few seconds after the key switch is turned off. This burns any fuel remaining in the engine to prevent backfires the next time the engine is started. When the key switch is turned off, the Engine System switches off the fuel supply to the engine, but keeps the ignition system on until it senses that the engine has stopped running.

Engine Protection – Low Oil Pressure Shutdown

The engine controller monitors the oil pressure switch. If it sees a loss of oil pressure, it will shut down the engine immediately.

Engine Protection – High Temperature

The engine controller monitors the engine coolant temperature. If the temperature reaches 230 deg. F. (110 deg. C.), it will derate the engine power by 30%. If the temperature reaches 240 deg. F. (115 deg. C.), it will shut down the engine.

Engine Speed Control

The operator can request three engine speeds, “idle” (1200 RPM), “run” (2200 RPM) and “maximum”

(2400 RPM). The Engine Controller operates an Electronic Throttle Body to adjust and maintain engine speed according to the requested input of the Main Machine Controller. To request the three different engine speeds, the Main Machine Controller (Driver Box) uses two wires that are connected to the Engine

Controller. It either applies 0v or 12v to each wire to request the specific speeds. See table below.

Pin#

Wire

Color

Function

J2-30 on Driver Box GRA/BLU Input from Driver Box

J2-29 on Driver Box GRA/ORN Input from Driver Box

Voltage at

1200 RPM

0

0

Voltage at

2200 RPM

0

+12 VDC

Voltage at

2400 RPM

+12 VDC

0

Service Manual – SC8000 Engine System, LPG 97

Component Locations

LPG Electrical Components

Note: Some of the photos in this section are of an engine before it is installed in the machine for better visual clarity.The engine is fitted for a different model machine (SW8000) so some details are slightly different like the air cleaner, air inlet and exhaust.

The following components are included in this section:

• Alternator

• Electronic Throttle Body

• Cam Position Sensor

• Connector 1

• Connector 2

• Crank Position Sensor

• DEPR - Direct Electronic Pressure Regulator

• Diagnostic Connector

• Engine Control Module

• Engine Coolant Sensor

• Fuel Lockoff Solenoid

• Ground

• Ignition Coils

• Knock Sensor

• LP Dual Stage Pressure Regulator

• Mixer Assembly

• Oil Pressure Switch

• Post Catalyst O

2

Sensor

• Power Relay (Inside Engine Fuse/Relay Box)

• Pre Catalyst O

2

Sensor

• Starter

• Starter Relay (Inside Engine Fuse/Relay Box)

• TMAP Sensor

Figure 1. Left Side

Connector 1 and

Connector 2

Engine Control

Module

Crank Position

Sensor

Knock Sensor

Electronic

Throttle Body

Service Manual – SC8000

Alternator

Oil Pressure

Switch

Oil Filter

Figure 2. Right Side

Diagnostic

Connector

TMAP

Sensor

Starter

Engine Fuse/

Relay Box

Engine System, LPG 98

Figure 3. Top

Ignition Coils

Service Manual – SC8000

Figure 4. Top, Front

Ground

Pre-Catalyst

O

2

Sensor

Engine System, LPG 99

Figure 5. Top, Rear

Engine Coolant

Sensor

Alternator

Mixer Assembly

Direct Electronic

Pressure Regulator

(DEPR)

Cam Position

Sensor

Oil Filter

Figure 6. Oxygen Sensors

Post-Catalyst

O

2

Sensor

Right Rear

Wheel

Fuel Lockoff

Solenoid

LP Dual Stage

Pressure Regulator

Figure 7. Top, Left Front

Service Manual – SC8000

Maintenance and Adjustments

Engine System, LPG 100

Warning! Before performing any machine maintenance or adjustments, make sure the key switch is off, the key is removed from the machine and the parking brake is engaged.

Maintenance Schedule

Item

Check engine oil level

Check and replenish coolant

Check and clean air filter element

Check LPG tank setting condition

Every

8 hrs

(daily).

X

X

if necessary if necessary

X

Every

50 hrs

(weekly)

Check LPG fuel connector

* Change engine oil

* Replace oil filter cartridge

Check LPG fuel hose and clamp bands

Clean spark plugs

Check fuel filter

Check fan belt tension and for damage

Check battery electrolyte level

Replace fuel filter

X

Every

100 hrs

X

X

X

X

if necessary

Check LPG tank setting condition

Check radiator hoses and clamp bands

Check PCV valve

Check coolant hose of LPG vaporizer

Check LPG Lock off valve

Check valve clearance

Replace spark plugs

** Replace air cleaner element

Clean water jacket and radiator interior

Replace intake air line

Replace breather hose

Replace LPG fuel hose and clamp bands

Replace coolant hose of LPG vaporizer

Service Interval

Every

150 hrs

Every

1000 hrs

Every

2000 hrs

X

X

X

X

X

X

X

X

X

Every

Year

X

X

Every

Two

Years

X

X

X

X

Service Manual – SC8000 Engine System, LPG 101

Item

*** Check LPG vaporizer

Replace radiator hoses and clamp bands

Change radiator coolant

Replace battery

Every

8 hrs

(daily).

Every

50 hrs

(weekly)

Every

100 hrs

Service Interval

Every

150 hrs

Every

1000 hrs

Every

2000 hrs

Every

Year

Every

Two

Years

X

X

X

X

* Change the engine oil and filter cartridge after the first 35 hours of operation.

** Change more often when operating under dusty conditions.

*** If you do not have the correct tools and/or are not mechanically proficient, contact your local KUBOTA dealer.

Engine Oil

Check the engine oil level when the machine is parked on a level surface and the engine is cool. Change the engine oil after the first 35 hours of operation and every 150 hours after that. Engine oil should have properties of API classification SL or higher and be suited to the ambient temperature as listed below. Refer to the engine manufacturer’s service manuals for oil capacities and additional engine specifications. Replace the oil filter with every oil change.

Temperature Range

Above 77° F [25° C]

32° F to 77° F [0° C to 25° C]

-4° F to 32° F [-20° C to 0° C]

Oil Weight

SAE30, SAE10W-30 or SAE15W-40

SAE20 or SAE 10W-30

SAE10 or SAE 10W-30

Engine Coolant

Checking Engine Coolant

Caution! Do not remove the radiator cap when the engine is hot.

To check the engine coolant level, open the engine cover and observe the coolant level in the coolant overflow tank. If the level is low, add a 50/50 mix of water and the recommended type antifreeze. Clean the radiator and oil cooler exteriors every 150 hours by washing with low-pressure water or using compressed air.

High-pressure water will damage the radiator.

Service Note: The oil cooler tips out for easy cleaning of both the oil cooler and the radiator.

Service Manual – SC8000 Engine System, LPG 102

Replacing Engine Coolant

One possible cause of engine overheating is trapped air in the cooling system. It’s recommended that you use a Cooling System Tool when changing the engine coolant. The Cooling System Tool pulls a vacuum on the cooling system prior to filling to prevent air from being trapped in the cooling system.

Note that there are several types of Cooling System Tools. The following instructions describe how to use a typical type of tool. Refer to the operating instructions included with your particular tool if different than the example shown here.

1. Connect a

Compressed Air Supply Line

to the fitting on the Cooling System

Tool.

Compressed Air

Supply Line

Gauge

Air

Switch

Coolant

Valve

(closed)

2. Connect the

Coolant Supply Line

to the

Cooling System Tool. Make sure the

Coolant Valve

is closed.

3. Insert and hold the Cooling System

Tool onto the radiator filler neck, then press the

Air Switch

. The compressed air travelling through the

Venturi Tube

Assembly

will pull a vacuum on the cooling system to remove air from the system.

Venturi

Tube

Assembly

Coolant

Supply

Line

4. Once the vacuum reading on the

Gauge

reaches approximately 25 on the green scale, release the

Air Switch

.

Note that this also a good opportunity to check for cooling system leaks,

Removing the Air from the Cooling System with Cooling System Tool

5. Continue to hold the Cooling System

Tool onto the radiator filler neck and open the

Coolant Valve

to allow coolant to flow into the radiator.

Gauge

Coolant

Valve

(open)

6. Once the pressure on the

Gauge

reaches approximately 5 on the red scale and the radiator is almost full, shut off the

Coolant Valve

and remove the Cooling System Tool from the radiator filler neck.

7. Top off the radiator and overflow tank as necessary.

Filling Cooling System with Coolant

Service Manual – SC8000 Engine System, LPG 103

Engine Air Filter Maintenance

Caution! When servicing the engine air filter elements, use extreme care to prevent loose dust from entering the engine. Dust can severely damage the engine.

Service the air cleaner more frequently under severe dusty or dirty conditions.

1. Remove the air cleaner elements from the air cleaner assembly and inspect them for foreign material restrictions or signs of excessive wear or damage. Replace the elements if necessary.

2. Remove all dust and foreign matter from the air cleaner housing.

3. Reinstall the air cleaner elements.

4. Reinstall the air cleaner cup, then securely fasten the retaining clips

Troubleshooting

The EControls engine management package supports robust self diagnostics and is capable of setting scores of Diagnostic Trouble Codes (DTCs). DTCs and sensor data can be viewed on a coputer using the “GCP

Display” software along with an “ECom” communication cable. See the Diagnosis Manual ECM System

WG1605 9Y110-01760.pdf for the diagnostic tool connection procedure.

The ECom cable can be purchased through Nilfisk-Advance. (See Special Tools in this section for the part number). It is the same cable that has been used on other recent Nilfisk-Advance machines using the GM

1.6L and GM 3.0L engines. You will need a new version of the GCP software to work with the Kubota

WG1605 engine along with the correlating password. The software, password and installation instructions can all be downloaded from “Customer Zone”at www.advance-us.com.

Most or all engine troubleshooting is covered in Kubota manuals. There are some things specific to the

SW8000 engine application which are covered here in this manual section such as, engine speed control and engine starter operation.

Note: Refer to the Diagnosis Manual ECM System WG1605 9Y110-01760.pdf, for engine

troubleshooting information and procedures including all fault code diagnosis.

General Troubleshooting

Problem

The engine will not crank.

Cause

Weak battery, poor battery cable connections.

No power to the Starter

Solenoid (Starter Command circuit)

Correction

• Check the battery and connections and clean/repair as necessary.

• Check the wiring from the battery to the Starter B+ terminal on the A3 Engine System and repair as necessary.

• Make sure the foot pedal is in the neutral position.

• Reset the foot pedal deadband position if necessary.

(Refer to the

Control System, / Main Machine

Controller Programming

section.)

• Make sure there is continuity through the Neutral

Relay K4 contacts 30 and 87a (relay off).

• Check the starter relay operation

• Check circuit breaker CB1 and reset if necessary.

• Check circuit breaker CB3 and reset if necessary.

Service Manual – SC8000 Engine System, LPG 104

Problem

The engine will not start.

Engine will not run at high speed.

The engine stops running, check engine light is on.

Cause

No power to the Ign. Switch

Input terminal on the A3

Engine System.

Loss of throttle input from

Main Machine Controller to

Engine Controller

Engine System Problem

The coolant temperature is too high.

Correction

• Check circuit breaker CB5 and reset if necessary.

• Check the continuity from the Ignition Switch to the

Ign. Switch Input terminal on the A3 Engine System and repair as necessary.

• Check that a voltage signal is being sent to the engine controller when the Throttle Switch is set to operating speed.

• Refer to Diagnosis Manual ECM System WG1605

9Y110-01760.pdf

Refer to the Engine Overheating Problems section below.

The oil pressure has dropped too low.

Refer to the Loss of Oil Pressure Protection section below.

Engine Management System

Problem

Consult Diagnosis Manual ECM System WG1605

9Y110-01760.pdf

Engine Overheating Problems

Use the checklist below as a guide to thoroughly check the engine cooling system.

• Check the coolant level in the overflow tank and radiator.

• Inspect and clean the radiator and hydraulic oil cooler.

• Check for correct operation of the belt-driven engine cooling fan (slippage).

• Check to see that the engine thermostat opens.

• Check for correct water pump operation.

• Check the engine crankcase oil level.

• Check for air trapped in the cooling system. (Refer to the

Engine Coolant/Replacing Engine Coolant

section.)

• Check the engine coolant sensor for correct function as replace if necessary.

• Check for combustion gasses in the coolaning system.

Service Manual – SC8000 Engine System, LPG 105

Specifications

Number of Cylinders

Type

Bore × Stroke

Total Displacement

Cylinder Head

Ignition System

Governor

Direction of Rotation

Spark Plug Type/Spark Plug Gap

Ignition Timing.

Firing Order

Model

Compression Ratio

Lubricating System

Oil Pressure Indication

Engine Oil Pressure (Hot)

At Idle Speed

At Rated Speed

Lubricating Filter

Cooling System Type

Starting System

Starting Motor

Battery

Charging Alternator

Fuel

Lubricating Oil

Lubricating Oil Capacity

Catalytic Muffler / Converter

Weight (Dry)

Kubota Recommended LPG Fuel

Specifications

WG1605-L-E3

LPG fuel

Four

Vertical, water cooled, four-cycle LPG engine

79.0 × 78.4 mm (3.11 × 3.09 in.)

1.537 L (93.79 cu.in.)

Overhead-Valve

Full Transistor Battery Ignition Type

Electronic Governor

Counterclockwise (Viewed from Flywheel Side)

NGK IFR6F8DN; 0.70 to 0.80 mm (0.028 to 0.031 in.)

0.35 rad (20 °) before T.D.C.

3000 min-1 (rpm), 3600 min-1 (rpm)

0.17 rad (10 °) before T.D.C.

750 min-1 (rpm), 800 min-1 (rpm)

1-3-4-2

9.1: 1

Forced Lubrication by Trochoid Pump

Electrical Type Switch

Allowable Limit Factory Specification

49 kPa

0.50 kgf/cm2

7.1 psi

–

196 to 441 kPa

2.00 to 4.49 kgf/cm2

28.5 to 63.9 psi

147 kPa

1.50 kgf/cm2

21.3 psi

Full Flow Paper Filter (Cartridge Type)

Pressurized Radiator, Forced Circulation with Water Pump

Electric Starting with Starter

12 V, 1.0 kW

12 V, 52 AH or Equivalent

12 V, 480 W, 720 W

Commercial LPG

Better than SL Class (API) SAE 10W-30

6.0 L (1.6 U.S.gals)

Three-way Catalyst

120 kg (265 lbs)

Commercial Propane gas only, Equivalent to Propanes H-D-5 of GPA* standards

Service Manual – SC8000 Engine System, LPG 106

Shop Measurements

The following information was gathered by measuring one machine. While the values recorded cannot serve as “true specifications” they may help you recognize what normal looks like and give you some standard of comparison.

Engine Vacuum

17.5-18 “HG (59-61kPa)-at warm idle. Measured at approximately 900 ft. elevation

LP Fuel Pressure

• Primary - Approximately 3 psi (20 kPa)

• Secondary - Approximately 1 psi (7 kPa)

Ignition Output

Cam Sensor and Crank Sensor Oscilloscope Pattern

Service Manual – SC8000

Special Tools

Diagnostic Communication Cable and software, p/n 56305647

Note: The “Ecom” cable is used but the software on the

CD is for the GM engines. New software must be ordered or downloaded from Customer Zone to use on the Kubota engine..

Cooling System Tool

CD containing Kubota Engine Software p/n 56107764

Engine System, LPG 107

Not Shown