Marine Electronic Fuel Injection (MEFI) Section 2 Engine Control

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Marine Electronic Fuel Injection (MEFI) Section 2 Engine Control | Manualzz
Section 2 - ECM and Sensors - 5.7L PFI
2-1
Marine Electronic Fuel Injection (MEFI)
Section 2
Engine Control Module (ECM) and Sensors
This section will describe the function of the Engine Control Module (ECM) and the sensors. The section explains how
voltages reflect the inputs and outputs of the ECM. The sensors are described how they operate and how to replace them.
Contents
General Description .........................................Page 2
Computers and Voltage Signals ....................Page 2
Analog Signals .............................................. Page 2
Three-Wire Sensors ................................Page 2
Two-Wire Sensors ..................................Page 2
Digital Signals ...............................................Page 3
Switch Types ..........................................Page 3
Pulse Counters .......................................Page 3
Engine Control Module (ECM) ...................... Page 4
ECM Function .........................................Page 4
Memory ..................................................Page 4
ROM ....................................................... Page 4
RAM ....................................................... Page 4
EEPROM ................................................Page 4
Speed Density System .................................Page 5
Speed .....................................................Page 5
Density ...................................................Page 5
ECM Inputs and Sensor Descriptions ...........Page 5
MEFI Inputs and Outputs .......................Page 6
Engine Coolant Temperature (ECT)
Sensor .................................................... Page 7
Manifold Absolute Pressure (MAP)
Sensor .................................................... Page 7
Knock Sensor .........................................Page 7
Throttle Position (TP) Sensor .................. Page 8
Ignition Control (IC) Reference ............... Page 8
Discrete Switch Inputs (Optional) ...........Page 8
Diagnosis ...........................................................Page 9
Engine Control Module (ECM) ...................... Page 9
On-Board Service ............................................. Page 9
Engine Control Module (ECM)
Replacement ................................................. Page 9
Engine Coolant Temperature (ECT)
Sensor ......................................................... Page 10
Manifold Absolute Pressure (MAP)
Sensor ......................................................... Page 10
Throttle Position (TP) Sensor ...................... Page 11
Idle Air Control (IAC) Valve .......................... Page 12
Knock Sensor (KS) ...................................... Page 13
Torque Specifications ..................................... Page 13
2003 Marine
2-2
General Description
The Marine Electronic Fuel Injection (MEFI) system is
equipped with a computer that provides the operator with
state-of-the-art control of fuel and spark delivery. Before we
discuss the computers on the Marine applications, let’s
discuss how computers use voltage to send and receive
information.
Computers and Voltage Signals
Voltage is electrical pressure. Voltage does not flow through
circuits. Instead, voltage causes current. Current does the
real work in electrical circuits. It is current, the flow of
electrically charged particles, that energizes solenoids,
closes relays and illuminates lamps.
Besides causing current flow in circuits, voltage can be used
as a signal. Voltage signals can send information by changing
levels, changing waveform (shape) or changing the speed
at which the signal switches from one level to another.
Computers use voltage signals to communicate with one
another. The different circuits inside computers also use
voltage signals to talk to each other.
There are two kinds of voltage signals, analog and digital.
Both of these are used in computer systems. It is important
to understand the difference between them and the different
ways they are used.
Analog Signals
An analog signal is continuously variable. This means that
the signal can be any voltage within a certain range.
An analog signal usually gives information about a condition
that changes continuously over a certain range. For example,
in a marine engine, temperature is usually provided by an
analog signal. There are two general types of sensors that
produce analog signals, the 3-wire and the 2-wire sensors.
Section 2 - ECM and Sensors - 5.7L PFI
Three-Wire Sensors
Figure 2-1 shows a schematic representation of a 3-wire
sensor. All 3-wire sensors have a reference voltage, a ground
and a variable “wiper.” The lead coming off of the “wiper” will
be the signal to the Engine Control Module (ECM). As this
“wiper” position changes, the signal voltage to the ECM also
changes.
ECM
TYPICAL
SENSOR
VOLTAGE OUT
SIGNAL INPUT
4-24-91
MS 11697
Figure 2-1 - Three-Wire Sensors
Two-Wire Sensors
Figure 2-2 shows a schematic representation of a 2-wire
sensor. This sensor is basically a variable resistor in series
with a known-fixed resistor within the ECM. By knowing the
values of the input voltage and the voltage drop across the
known resistor, the value of the variable resistor can be
determined. The variable resistors that are commonly used
are called thermistors. A thermistor’s resistance varies with
temperature.
ECM
TYPICAL
SENSOR
SENSOR
SIGNAL
5V
SENSOR
GROUND
4-24-91
MS 11698
Figure 2-2 - Two-Wire Sensors
2003 Marine
Section 2 - ECM and Sensors - 5.7L PFI
Digital Signals
Digital signals are also variable, but not continuously. They
can only be represented by distinct voltages within a range.
For example, 1V, 2V or 3V would be allowed, but 1.27V or
2.56V would not. Digital signals are especially useful when
the information can only refer to two conditions: “YES” and
“NO,” “ON” and “OFF” or “HIGH” and “LOW.” This would be
called a digital binary signal. A digital binary signal is limited
to two voltage levels. One level is a positive voltage, the other
is no voltage (zero volts). As you can see in Figure 2-3, a
digital binary signal is a square wave.
The ECM uses digital signals in a code that contains only
ones and zeros. The high voltage of the digital signal
represents a one (1), and no voltage represents a zero (0).
Each “zero” and each “one” is called a bit of information, or
just a “bit.” Eight bits together are called a “word.” A word,
therefore, contains some combination of eight binary code
bits.
Binary code is used inside the ECM and between a computer
and any electronic device that understands the code. By
stringing together thousands of bits, computers can
communicate and store an infinite varieties of information.
To a computer that understands binary, 11001011 might
mean that it should turn an output device “ON” at slow speed.
Although the ECM uses 8-bit digital codes internally and
when talking to another computer, each bit can have a
meaning.
2-3
Switch Types
Switched inputs (also known as discretes) to the ECM can
cause one bit to change, resulting in information being
communicated to the ECM. Switched inputs can come in
two types: “pull-up” and “pull-down” types. Both types will be
discussed.
With “pull-up” type switch, the ECM will sense a voltage when
the switch is CLOSED. With “pull-down” type switch, the ECM
will sense a voltage when the switch is OPEN.
Pulse Counters
For the ECM to determine frequency information from a
switched input, the ECM must measure the time between
the voltage pulses. As a number of pulses are recorded in a
set amount of time, the ECM can calculate the frequency.
The meaning of the frequency number can have any number
of meanings to the ECM.
An example of a pulse counter type of input is the distributor
reference pulse input. The ECM can count a train of pulses,
a given number of pulses per engine revolution. In this way,
the ECM can determine the RPM of the engine.
DIGITAL BINARY SIGNAL
V
O
L
T
A
G
E
TIME
4-18-91
MS 11696
Figure 2-3 - Digital Voltage Signal
2003 Marine
2-4
Section 2 - ECM and Sensors - 5.7L PFI
Engine Control Module (ECM)
The Engine Control Module (ECM), located on the engine,
is the control center of the fuel injection system. It controls
the following:
• Fuel metering system.
• Ignition timing.
• Idle speed.
• On-board diagnostics for engine functions.
It constantly looks at the information from various sensors,
and controls the systems that affect engine performance.
The ECM also performs the diagnostic function of the system.
It can recognize operational problems, alert the driver through
the MIL (Malfunction Indicator Lamp) and store diagnostic
trouble codes which identify the problem areas to aid the
technician in making repairs. Refer to General Information
section for more information on using the diagnostic function
of the ECM.
ECM Function
The ECM supplies either 5 or 12 volts to power various
sensors or switches. This is done through resistances in the
ECM which are so high in value that a test light will not light
when connected to the circuit. In some cases, even an
ordinary shop voltmeter will not give an accurate reading
because its resistance is too low. Therefore, a digital voltmeter
with at least 10 megohms input impedance is required to
ensure accurate voltage readings. Tool J 39978 meets this
requirement.
The ECM controls output circuits such as the injectors, IAC,
relays, etc. by controlling the ground or power feed circuit.
Memory
There are three types of memory storage within the ECM.
They are ROM, RAM and EEPROM.
ROM
Read Only Memory (ROM) is a permanent memory that is
physically soldered to the circuit boards within the ECM. The
ROM contains the overall control programs. Once the ROM
is programmed, it cannot be changed. The ROM memory is
non-erasable, and does not need power to be retained.
RAM
Random Access Memory (RAM) is the microprocessor
“scratch pad.” The processor can write into, or read from this
memory as needed. This memory is erasable and needs a
constant supply of voltage to be retained. If the voltage is
lost, the memory is lost.
EEPROM
The Electronically Erasable Programmable Read Only
Memory (EEPROM) is a permanent memory that is
physically soldered within the ECM. The EEPROM contains
program and calibration information that the ECM needs to
control engine operation.
The EEPROM is not replaceable. If the ECM is replaced,
the new ECM will need to be programmed by the OEM with
the calibration information that is specific to each marine
application.
J1
Figure 2-4 - Engine Control Module (ECM)
2003 Marine
J2
MEFI3004
Section 2 - ECM and Sensors - 5.7L PFI
Speed Density System
The Marine Electronic Fuel Injection (MEFI) system is a
speed and air density system. The system is based on “speed
density” fuel management.
Sensors provide the ECM with the basic information for the
fuel management portion of its operation. Signals to the ECM
establish the engine speed and air density factors.
2-5
ECM Inputs and Sensor Descriptions
Figure 2-5 lists the data sensors, switches and other inputs
used by the ECM to control its various systems. Although
we will not cover them all in great detail, there will be a brief
description of each.
Speed
The engine speed signal comes from the Ignition Control
(IC) module to the ECM on the IC reference high circuit. The
ECM uses this information to determine the “speed” or RPM
factor for fuel and spark management.
Density
One particular sensor contributes to the density factor, the
Manifold Absolute Pressure (MAP) sensor. The MAP sensor
is a 3-wire sensor that monitors the changes in intake
manifold pressure which results from changes in engine
loads. These pressure changes are supplied to the ECM in
the form of electrical signals.
As intake manifold pressure increases, the vacuum
decreases. The air density in the intake manifold also
increases, and additional fuel is needed.
The MAP sensor sends this pressure information to the ECM,
and the ECM increases the amount of fuel injected, by
increasing the injector pulse width. As manifold pressure
decreases, the vacuum increases, and the amount of fuel is
decreased.
These two inputs, MAP and RPM, are the major determinants
of the air/fuel mixture delivered by the fuel injection system.
The remaining sensors and switches provide electrical inputs
to the ECM, which are used for modification of the air/fuel
mixture, as well as for other ECM control functions, such as
idle control.
2003 Marine
2-6
Section 2 - ECM and Sensors - 5.7L PFI
MEFI INPUTS AND OUTPUTS
(TYPICAL)
INPUTS
OUTPUTS
BATTERY 12V
E
L
E
C
T
R
O
N
I
C
IGNITION 12V
DISTRIBUTOR
REFERENCE(RPM)
THROTTLE POSITION
(TP) SENSOR
MANIFOLD ABSOLUTE
PRESSURE(MAP)
ENGINE COOLANT
TEMPERATURE (ECT)
SENSOR
INTAKE AIR
TEMPERATURE (IAT)
KNOCK SENSOR 1
KNOCK SENSOR 2
C
O
N
T
R
O
L
DIAGNOSTIC ENABLE
VESSEL SPEED SENSOR
(OPTIONAL)
FUEL PRESSURE SENSOR
(OPTIONAL)
OIL LEVEL (OPTIONAL)
OIL PRESSURE (OPTIONAL)
FUEL INJECTORS
IGNITION CONTROL (IC)
FUEL PUMP RELAY
IDLE AIR CONTROL (IAC)
DRIVER INFORMATION
LAMPS/BUZZERS (OPTIONAL)
SERIAL DATA (ECM
COMMUNICATION)
V- REFERENCE
(5 VOLT OUTPUT
TO SENSORS)
MALFUNCTION INDICATOR
LAMP (MIL)
EMERGENCY STOP
(OPTIONAL)
RPM CHANGE STATE
(OPTIONAL)
SHIFT INTERRUPT/LOAD ANTICIPATE 1
(OPTIONAL)
LOAD ANTICIPATE 2
(OPTIONAL)
GENERAL WARNING 1
(OPTIONAL)
M
O
D
U
L
E
GENERAL WARNING 2
(OPTIONAL)
5-96
MS 11699
Figure 2-5 - ECM Inputs and Outputs (Typical)
2003 Marine
Section 2 - ECM and Sensors - 5.7L PFI
Engine Coolant Temperature (ECT) Sensor
The engine coolant temperature (ECT) sensor is a thermistor
(a resistor which changes value based on temperature)
mounted in the engine coolant stream. Low coolant
temperature produces a high resistance (100,000 ohms at 40°C/-40°F) while high temperature causes low resistance
(70 ohms at 130°C/266°F).
The ECM supplies a 5 volt signal to the ECT sensor through
a resistor in the ECM and measures the voltage. The voltage
will be high when the engine is cold, and low when the engine
is hot. By measuring the voltage, the ECM calculates the
engine coolant temperature. Engine coolant temperature
affects most systems the ECM controls.
A hard fault in the engine coolant sensor circuit should set
DTC 14 or DTC 15; an intermittent fault may or may not set
a DTC. The DTC “Diagnostic Aids” also contains a chart to
check for sensor resistance values relative to temperature.
2-7
The ECM supplies a 5 volt reference voltage to the MAP
sensor. As the manifold pressure changes, the electrical
resistance of the MAP sensor also changes. By monitoring
the sensor output voltage, the ECM knows the manifold
pressure. A higher pressure, low vacuum (high voltage)
requires more fuel. A lower pressure, high vacuum (low
voltage) requires less fuel. The ECM uses the MAP sensor
to control fuel delivery and ignition timing. A failure in the
MAP sensor circuit should set a DTC 33 or DTC 34.
3
1
I 22312
2
Figure 2-7 - Manifold Absolute Pressure (MAP) Sensor
Knock Sensor
The knock sensor is mounted in the engine block. The
location depends on engine application.
1 HARNESS CONNECTOR
2 LOCKING TAB
3 SENSOR
8-24-94
RS 22189
Figure 2-6 - Engine Coolant Temperature (ECT) Sensor
Manifold Absolute Pressure (MAP) Sensor
The Manifold Absolute Pressure (MAP) sensor (Figure 2-7)
is a pressure transducer that measures the changes in the
intake manifold pressure. The pressure changes as a result
of engine load and speed change, and the MAP sensor
converts this into a voltage output.
A closed throttle on engine coastdown would produce a
relatively low MAP output voltage, while a wide open throttle
would produce a high MAP output voltage. This high output
voltage is produced because the pressure inside the manifold
is almost the same as outside the manifold, so you measure
almost 100% of outside air pressure. MAP is the opposite of
what you would measure on a vacuum gauge. When manifold
pressure is high, vacuum is low, causing a high MAP output
voltage. The MAP sensor is also used to measure barometric
pressure under certain conditions, which allows the ECM to
automatically adjust for different altitudes.
8-24-94
RS 22183
Figure 2-8 - Knock Sensor (Typical)
An ECM is used in conjunction with a knock sensor in order
to control detonation. The knock module circuitry is internal
in the ECM.
When knock is present, a small AC voltage is produced by
the knock sensor and transmitted to the ECM. An AC voltage
monitor inside the ECM will detect the knock and start
retarding spark timing.
2003 Marine
2-8
Section 2 - ECM and Sensors - 5.7L PFI
Throttle Position (TP) Sensor
The Throttle Position (TP) sensor is a potentiometer
connected to the throttle shaft on the throttle body. By
monitoring the voltage on the signal line, the ECM calculates
throttle position. As the throttle valve angle is changed
(accelerator pedal moved), the TP sensor signal also
changes. At a closed throttle position, the output of the TP
sensor is low. As the throttle valve opens, the output increases
so that at Wide Open Throttle (WOT), the output voltage
should be above 4 volts.
The ECM calculates fuel delivery based on throttle valve
angle (driver demand). A broken or loose TP sensor may
cause intermittent bursts of fuel from an injector and unstable
idle because the ECM thinks the throttle is moving. A hard
failure in the TP sensor circuit should set either a DTC 21 or
DTC 22. Once a DTC is set, the ECM will use a calibratible
default value for throttle position and some engine
performance will return.
1
2
1 THROTTLE POSITION (TP) SENSOR
2 TP SENSOR ATTACHING SCREW
RS 22191
Figure 2-9 - Throttle Position (TP) Sensor (Typical)
C
B
CONTROL
MODULE
A
2
1
1 THROTTLE POSITION (TP) SENSOR
2 THROTTLE VALVE
RS 22192
Figure 2-10 - Throttle Position (TP) Sensor (Typical)
2003 Marine
Ignition Control (IC) Reference
The Ignition Control (IC) reference (RPM signal) is supplied
to the ECM by way of the IC reference line from the ignition
module. This pulse counter type input creates the timing
signal for the pulsing of the fuel injectors, as well as the IC
functions. This signal is used for a number of control and
testing functions within the ECM.
Discrete Switch Inputs (Optional)
Several discrete switch inputs are utilized by the MEFI system
to identify abnormal conditions that may affect engine
operation. Pull-up and pull-down type switches are currently
used in conjunction with the ECM to detect critical conditions
to engine operation.
If a switch changes states from its normal at rest position,
that is, normally closed to open, or normally open to closed,
the ECM senses a change in voltage and responds by
entering RPM reduction mode.
This engine protection feature allows the operator normal
engine operations up to OEM specifications (approx. 2000
RPM), but disables half the fuel injectors until the engine
drops below 1200 RPM. Then normal engine operation is
restored until the RPM limit is exceeded. This feature allows
the operator a safe maneuvering speed while removing the
possibility of high RPM engine operation until the problem is
corrected.
Switches that may be used with the MEFI system to detect
critical engine operation parameters are:
N/O
• Oil level
N/O
• Oil pressure
N/O
• Emergency stop
General
Warning
1
N/O
•
N/O
• General Warning 2
N/O
• Shift Interrupt/Load Anticipate 1
N/O
• Load Anticipate 2
Section 2 - ECM and Sensors - 5.7L PFI
2-9
Diagnosis
On-Board Service
Engine Control Module (ECM)
Engine Control Module (ECM)
To read and clear diagnostic trouble codes, use a scan tool
or Marine Diagnostic Trouble Code (MDTC) tool.
Important: Use of a scan tool is recommended to clear
diagnostic trouble codes from the ECM memory. Diagnostic
trouble codes can also be cleared by using the MDTC tool,
TA 06075.
Since the ECM can have a failure which may affect more
than one circuit, following the diagnostic procedures will
determine which circuit has a problem and where it is.
If a diagnostic table indicates that the ECM connections or
ECM is the cause of a problem and the ECM is replaced,
but does not correct the problem, one of the following may
be the reason:
• There is a problem with the ECM terminal connections.
The diagnostic table will say ECM connections or ECM.
The terminals may have to be removed from the
connector in order to check them properly.
• EEPROM program is not correct for the application.
Incorrect components may cause a malfunction and may
or may not set a DTC.
• The problem is intermittent. This means that the problem
is not present at the time the system is being checked.
In this case, refer to the Symptoms portion of the manual
and make a careful physical inspection of all portions of
the system involved.
• Shorted relay coil or harness. Relays are turned “ON”
and “OFF” by the ECM using internal electronic switches
called drivers. A shorted relay coil or harness will not
damage the ECM but will cause the relay to be
inoperative.
Figure 2-11
Notice: When replacing the ECM, the ignition must be “OFF”
and disconnect the battery before disconnecting or
reconnecting the ECM “J1” and “J2” connectors to prevent
internal damage to the ECM.
Notice: To prevent possible electrostatic discharge damage
to the ECM, do not touch the connector pins. The ECM is an
electrical component. Do Not soak in any liquid cleaner or
solvent, as damage may result.
Remove or Disconnect
1. Negative battery cable.
2. “J1” and “J2” connectors from ECM.
3. Four ECM mounting screws.
4. ECM from mounting bracket.
Important
• Make sure the new ECM has the same part number
and service number as the old ECM, to insure proper
engine performance.
Install or Connect
1. New ECM to mounting bracket.
2. Three ECM mounting screws. Torque to 10-14 N•m (88124 lb.in.).
3. “J1” and “J2” connectors to ECM.
4. Negative battery cable.
J1
J2
MEFI3004
Figure 2-11 - Engine Control Module (ECM)
2003 Marine
2 - 10
Section 2 - ECM and Sensors - 5.7L PFI
Engine Coolant Temperature (ECT) Sensor
Figure 2-12
Notice: Care must be taken when handling the ECT sensor.
Damage to the sensor will affect proper operation of the
MEFI system.
Remove or Disconnect
1. Negative battery cable.
2. ECT electrical connector.
3. ECT sensor.
Important
• Coat ECT sensor threads with teflon tape sealant prior
to installation.
Install or Connect
1. ECT sensor. Torque to 12 N•m (108 lb.in.).
2. ECT electrical connector.
3. Negative battery cable.
Important
• The MAP sensor is an electrical component. Do Not
soak in any liquid cleaner or solvent, as damage may
result.
Install or Connect
1. New seal on MAP sensor.
2. MAP sensor.
3. MAP sensor attaching screws. Torque to 5-7 N•m (4462 lb.in.).
4. MAP sensor electrical connector.
5. Negative battery cable.
2
1
3
3
1
1 MAP SENSOR SEAL
T
FR
2 MAP SENSOR
3 MAP SENSOR ATTACHING SCREWS
2
Figure 2-13 - MAP Sensor Mounting Location
1 ENGINE COOLANT TEMERATURE (ECT) SENSOR
2 INTAKE MANIFOLD
P 22326
P 22326
Figure 2-12 - Engine Coolant Temperature (ECT) Sensor
Manifold Absolute Pressure (MAP) Sensor
Figures 2-13 and 2-14
Remove or Disconnect
1. Negative battery cable.
2. MAP sensor electrical connector.
3. MAP sensor attaching screws.
4. MAP sensor with seal.
I 22312
Figure 2-14 - Manifold Absolute Pressure (MAP) Sensor
2003 Marine
Section 2 - ECM and Sensors - 5.7L PFI
2 - 11
Throttle Position (TP) Sensor
Figures 2-15 and 2-16
Remove or Disconnect
1. TP sensor electrical connector.
2. TP sensor attaching screws.
3. TP sensor and seal.
1
2
Important
• The TP sensor is an electrical component. Do Not soak
in any liquid cleaner or solvent, as damage may result.
• If replacing TP sensor, install new screws that are
supplied with the TP sensor service package.
Install or Connect
1. With throttle valve in the normal closed position (idle),
install TP sensor on throttle body assembly, making sure
TP sensor pickup lever lines up with the tang on the
throttle actuator lever.
2. TP sensor attaching screws. Torque to 2 N•m (18 lb.in.).
3. TP sensor electrical connector.
1 THROTTLE POSITION (TP) SENSOR
2 TP SENSOR ATTACHING SCREW
RS 22191
Figure 2-15 - Throttle Position (TP) Sensor (Typical)
2
3
1
4
7
1 THROTTLE BODY ASSEMBLY
5
2 IAC VALVE SEAL
3 IAC VALVE ATTACHING SCREW
4 IAC VALVE
5 TP SENSOR
6 TP SENSOR ATTACHING SCREW
6
7 TP SENSOR SEAL
P 22328
Figure 2-16 - Throttle Body Assembly
2003 Marine
2 - 12
Section 2 - ECM and Sensors - 5.7L PFI
Idle Air Control (IAC) Valve
➤
Figures 2-17 and 2-18
➤
➤
Clean and Inspect
• Clean IAC valve O-ring sealing surface, pintle valve seat
and air passage.
– Use carburetor cleaner to remove carbon deposits.
Do Not use a cleaner that contains methyl ethyl
ketone, an extremely strong solvent, and not
necessary for this type of deposit.
– Shiny spots on the pintle or seat are normal, and
do not indicate misalignment or a bent pintle shaft.
B
2
➤
Remove or Disconnect
1. Flame arrestor.
2. IAC electrical connector.
3. IAC valve attaching screws.
4. IAC valve O-ring and discard.
Notice: On IAC valves that have been in service, Do Not
push or pull on the IAC valve pintle. The force required to
move the pintle may damage the threads on the worm drive.
Also, Do Not soak IAC valve in any liquid cleaner or solvent,
as damage may result.
A
1
1 O-RING - IAC VALVE
2 IAC VALVE ATTACHING SCREW
A DISTANCE OF PINTLE EXTENSION
Figure 2-17 - Flange Mounted Type IAC Valve
1
2
A
Important
• If installing a new IAC valve, be sure to replace with an
identical part number. IAC valve pintle shape and
diameter are designed for the specific application.
Measure (If installing a new IAC valve)
Figure 2-17
• Distance between tip of IAC valve pintle and mounting
surface.
– If greater than 28 mm, use finger pressure to slowly
retract the pintle. The force required to retract the
pintle of a new valve will not cause damage to the
valve.
Install or Connect
1. New O-ring on IAC valve and lubricate.
Notice: New IAC valves have been preset at the factory
and should not require any adjustment.
2. IAC valve to throttle body using attaching screws. Torque
to 3.2 N•m (28 lb.in.).
3. IAC valve electrical connector.
4. Reset IAC valve pintle position:
• Turn ignition “OFF” for 10 seconds.
• Start and run engine for 5 seconds.
• Ignition “OFF” for 10 seconds.
• Restart engine and check for proper idle.
2003 Marine
8-24-94
RS 22181
B DIAMETER OF PINTLE
4
B
3
1 IDLE AIR CONTROL (IAC) VALVE
2 THROTTLE BODY ASSEMBLY
3 THROTTLE VALVE
4 IAC VALVE PINTLE
A ELECTRICAL INPUT SIGNAL
B AIR INLET
8-25-94
RS 22193
Figure 2-18 - IAC Valve Air Flow Diagram (Typical)
Section 2 - ECM and Sensors - 5.7L PFI
2 - 13
Knock Sensor (KS)
Figures 2-19 and 2-20
2
Remove or Disconnect
1. Negative battery cable.
2. Knock sensor electrical connector.
3. Knock sensor from engine block.
Important
• If installing a new knock sensor, be sure to replace with
an identical part number.
• When installing knock sensor, be sure to install in the
same location removed from.
• If installing knock sensor in water jacket, use teflon sealer
#1052040 or equivalent.
FRT
1
1 KNOCK SENSOR
2 ENGINE BLOCK
RS 22182
Figure 2-19 - Knock Sensor Location
Install or Connect
1. Knock sensor into engine block. Be sure threads are
clean. Torque to 15-22 N•m (11-16 lb.ft.).
2. Knock sensor electrical connector.
3. Negative battery cable.
8-24-94
RS 22183
Figure 2-8 - Knock Sensor (Typical)
Torque Specifications
Fastener Tightening Specifications
Application
ECM Mounting Screws
ECT Sensor
MAP Sensor Attaching Screws
TP Sensor Attaching Screws
IAC Valve Attaching Screws
Knock Sensor
N•m
10-14
12
5-7
2
3.2
15-22
Lb Ft
Lb In
88-124
108
44-62
18
28
11-16
2003 Marine

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