Материал: 92FWD_14

Fig. 12 Fuel Rail Assembly

REMOVAL

(1)Perform fuel system pressure release procedure.

(2)Disconnect negative cable from battery.

(3)Disconnect vacuum hose from fuel pressure regulator (Fig. 13).

Place a shop towel under fuel pressure regulator to absorb any fuel spillage.

(4)Using 2 open end wrenches, one on the fuel pressure regulator and the other on the fuel return tube nut, loosen tube nut. The 2 wrenches must be used, otherwise damage will occur (Fig. 13).

(5)Remove fuel pressure regulator mounting nuts. Remove fuel pressure regulator from rail (Fig. 14). Check O-Ring for damage. Replace damaged O-Rings.

Fig. 13 Servicing Fuel Pressure Regulator

INSTALLATION

(1)Lubricate O-ring with a drop of clean engine oil. Install O-ring into the receiver cup on fuel rail.

(2)Install mounting nuts. Tighten nuts to 7 NIm (65 in. lbs.) torque.

(3)Connect fuel return tube to pressure regulator.

Using a wrench to hold the fuel pressure regulator, tighten the nut to 28 NIm (250 in. lbs.) torque (Fig. 13).

(4)Connect vacuum hose to pressure regulator. Replace clamp.

(5)Connect negative cable to battery.

CAUTION: When using the ASD Fuel System Test, the Auto Shutdown (ASD) Relay remains energized for either 7 minutes, until the test is stopped, or until the ignition switch is turned to the Off position.

(6) With the DRB II use the ASD Fuel System Test to pressurize system and check for leaks.

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR SERVICE

(1)Remove vacuum hose and remove mounting screws from sensor (Fig. 14).

(2)Remove wiring harness and remove sensor.

(3)Reverse the above procedure for installation.

Fig. 14 Manifold Absolute Pressure Sensor

WASTEGATE SOLENOID AND CANISTER PURGE SOLENOID

(1)Remove vacuum hose and electrical connector from solenoids (Fig. 15).

(2)Remove solenoid pack mounting nut. Remove solenoid pack.

(3)Depress tab on top of solenoid to be replaced and slide the solenoid downward out of mounting bracket.

(4)Reverse above procedure for installation.

ENGINE CONTROLLER SERVICE

(1)Remove air cleaner duct from engine controller.

(2)Remove battery.

(3)Remove engine controller mounting screws (Fig.

16).

(4)Remove 60 way wiring connector from module and remove module.

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Fig. 15 Solenoid Mounting Turbo I Engines

(5) Reverse the above procedure for installation.

Fig. 16 Engine Controller Removal

HEATED OXYGEN SENSOR (O2 SENSOR)

The oxygen sensor is installed in the exhaust manifold (Fig. 17).

CAUTION: Do not pull on the oxygen sensor wires when disconnecting the electrical connector.

WARNING: THE EXHAUST MANIFOLD MAY BE EXTREMELY HOT. USE CARE WHEN SERVICING THE OXYGEN SENSOR.

FUEL SYSTEMS 14 - 75

Fig. 17 Oxygen Sensor

(1)Disconnect oxygen sensor electrical connector.

(2)Remove sensor using Tool C-4907 (Fig. 18).

Fig. 18 Oxygen Sensor Socket

When the sensor is removed, the exhaust manifold threads must be cleaned with an 18 mm X 1.5 + 6E tap. If using original sensor, coat the threads with Loctite 771-64 anti-seize compound or equivalent. New sensors are packaged with compound on the threads and do not require additional compound. The sensor must be tightened to 27 NIm (20 ft. lbs.) torque.

SYSTEM DIAGNOSIS

The engine controller tests many of its own input and output circuits. If a fault is found in a major system, the information is stored in memory. Technicians can display fault information through the instrument panel Check Engine lamp. Also, the technician can read fault information by connecting the Diagnostic Readout Box II (DRB II) to the diagnostic connector. For fault code information, refer to On Board Diagnostics in 2.2L Turbo III Multi-Point Fuel InjectionÐGeneral Diagnosis section of this group.

CCD BUS

Various controllers and modules exchange information through a communications port called the CCD Bus. The engine controller transmits vehicle load data on the CCD Bus.

ENGINE CONTROLLER

The engine controller is a digital computer containing a microprocessor (Fig. 2). The controller receives input signals from various switches and sensors that are referred to as Engine Controller Inputs. Based on these inputs, the controller adjusts various engine and vehicle operations through devices that are referred to as Engine Controller Outputs.

Fig. 2 Engine Controller

Engine Controller Inputs:

²Air Conditioning Controls

²Battery Voltage

²Brake Switch

²Camshaft Sensor

²Crankshaft Sensor

²Charge Air Temperature Sensor

²Coolant Temperature Sensor

²Detonation Sensor

²Manifold Absolute Pressure (MAP) Sensor

²Oxygen Sensor

²SCI Receive

²Speed Control System Controls

²Throttle Position Sensor

²Vehicle Distance (Speed) Sensor

Engine Controller Outputs:

²Air Conditioning Clutch Relay

²Alternator Field

²Automatic Idle Speed (AIS) Motor

²Auto Shutdown (ASD) Relay

²Barometric Read Solenoid

²Canister Purge Solenoid

²Check Engine Lamp

²Diagnostic Connector

²Fuel Injectors

²Ignition Coil

²Radiator Fan Relay

²Speed Control Solenoids

²Tachometer Output

²Wastegate Solenoid

Based on inputs it receives, the engine controller adjusts fuel injector pulse width, idle speed, ignition spark advance, ignition coil dwell and canister purge operation. The engine controller regulates operation of the cooling fan, A/C and speed control systems. The controller changes alternator charge rate by adjusting the alternator field.

14 - 78 FUEL SYSTEMS

The engine controller adjusts injector pulse width (air-fuel ratio) based on the following inputs.

²battery voltage

²coolant temperature

²exhaust gas content

²engine speed (crankshaft sensor)

²manifold absolute pressure

²throttle position

The engine controller adjusts ignition timing based on the following inputs.

²coolant temperature

²detonation sensor

²engine speed (crankshaft sensor)

²manifold absolute pressure

²throttle position

The Automatic Shut Down (ASD) and Fuel Pump relays are mounted externally, but turned on and off by the engine controller through the same circuit.

The ignition pick-up signals, (camshaft and crankshaft) are sent to the engine controller. If the engine controller does not receive both signals within approximately one second of engine cranking, it deactivates the ASD relay and fuel pump relay. When these relays are deactivated, power is shut off to the fuel injector, ignition coil, oxygen sensor heating element and fuel pump.

The engine controller contains a voltage converter that changes battery voltage to a regulated 9.0 volts. The 9.0 volts power the camshaft sensor, crankshaft sensor and vehicle speed sensor. The controller also provides a 5.0 volts supply for the coolant temperature sensor, manifold absolute pressure sensor and throttle position sensor.

AIR CONDITIONING SWITCH SENSEÐENGINE CONTROLLER INPUT

When the air conditioning or defrost switch is put in the ON position and the low pressure and high pressure switches are closed, the engine controller receives an input for air conditioning. After receiving this input, the engine controller activates the A/C compressor clutch by grounding the A/C clutch relay. The engine controller also adjusts idle speed to a scheduled RPM to compensate for increased engine load.

BATTERY VOLTAGEÐENGINE CONTROLLER INPUT

The engine controller monitors the battery voltage input to determine fuel injector pulse width and alternator field control. If battery voltage is low the engine controller will increase injector pulse width (period of time that the injector is energized).

BRAKE SWITCHÐENGINE CONTROLLER INPUT

When the brake switch is activated, the engine controller receives an input indicating that the brakes are being applied. After receiving this input, the engine controller vents the speed control servo. Venting

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the servo turns the speed control system off. The brake switch is mounted on the brake pedal support bracket.

CAMSHAFT SENSORÐENGINE CONTROLLER INPUT

Fuel injection synchronization and cylinder identification are provided through the camshaft reference sensor (Fig. 3). The sensor generates pulses. The pulse are the input sent to the engine controller. The engine controller interprets the camshaft sensor input along with the crankshaft sensor input to determine crankshaft position. The engine controller uses crankshaft position reference to determine injector sequence and ignition timing.

Fig. 3 Camshaft Sensor

The camshaft sensor senses when a slot in the camshaft gear passes beneath it (Fig. 4). When a slot is sensed, the input voltage from the sensor to the engine controller switches from high (5 volts) to low (less than .3 volts). As the slot or window passes, the input voltage is switched back to high (5 volts).

The camshaft sensor is mounted on the top of the cylinder head (Fig. 5). The bottom of the sensor is positioned above the camshaft sprocket. The distance between the bottom of sensor and the camshaft sprocket is critical to the operation of the system. When servicing the camshaft sensor, refer to the 2.2L Turbo III Multi-Point Fuel InjectionÐService Procedures section in this Group.

CHARGE TEMPERATURE SENSORÐENGINE CONTROLLER INPUT

The Charge Temperature Sensor is mounted to intake manifold. The sensor measures the temperature of the air-fuel mixture (Fig. 6). This information is used by the engine controller to modify air/fuel mixture and turbocharger boost level.

Fig. 4 Camshaft Gear

Fig. 5 Camshaft Sensor Location

COOLANT TEMPERATURE SENSORÐENGINE CONTROLLER INPUT

The coolant temperature sensor is a variable resistor with a range of -40°C to 128°F (-40°F to 265°F). The sensor is installed into the thermostat housing (Fig. 7).

The engine controller supplies 5.0 volts to the coolant temperature sensor. The sensor provides an input voltage to the engine controller. The engine controller determines engine operating temperature from this input. As coolant temperature varies, the sensor resistance changes resulting in a different input voltage to the engine controller.

Based on the coolant sensor and charge air temperature sensor inputs the controller changes certain operating schedules until the engine reaches operating temperature. While the engine warms up, the

Fig. 6 Charge Temperature Sensors

Fig. 7 Coolant Temperature Sensor

controller demands slightly richer air-fuel mixtures, lower boost levels, revised spark advance and higher idle speeds.

CRANKSHAFT SENSORÐENGINE CONTROLLER INPUT

The crankshaft sensor (Fig. 8) senses slots cut into the flywheel. There are a 2 sets of slots. Each set contains 4 slots, for a total of 8 slots (Fig. 9). Basic timing is set by the position of the last slot in each group. Once the engine controller senses the last slot, it determines crankshaft position (which piston will next be at TDC) from the camshaft sensor input. It may take the controller one engine revolution to determine crankshaft position. The Turbo III engine uses a fixed ignition system. Base timing is not adjustable.

The engine controller uses the crankshaft position reference to determine injector sequence and ignition timing. Once crankshaft position has been determined, the engine controller begins energizing the injectors in sequence.

Fig. 8 Crankshaft Sensor

Fig. 9 Timing Slots

The crankshaft sensor is located in the transmission housing, below the throttle body (Fig. 10). The bottom of the sensor is positioned next to the drive plate. The distance between the bottom of sensor and the drive plate is critical to the operation of the system. When servicing the crankshaft sensor, refer to the 2.2L Turbo III MultiPoint Fuel InjectionÐService Procedures section in this Group.

DETONATION SENSOR (KNOCK SENSOR)ÐENGINE CONTROLLER INPUT

The detonation sensor generates a signal when spark knock occurs in the combustion chambers. The sensor can detect detonation in the cylinders. The sensor provides information used by the engine controller to modify spark advance and boost schedules in order to eliminate detonation.

The detonation sensor is installed into the engine, behind the PCV breather/separator (Fig. 11).

Fig. 10 Crankshaft Sensor Location

Fig. 11 Detonation (Knock) Sensor

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSORÐENGINE CONTROLLER INPUT

The engine controller supplies 5 volts to the MAP sensor. The Map sensor converts intake manifold pressure into voltage. The engine controller monitors the MAP sensor output voltage. As vacuum increases, MAP sensor voltage decreases proportionately. Also, as vacuum decreases, MAP sensor voltage increases proportionately.

During cranking, before the engine starts running, the engine controller determines atmospheric air pressure from the MAP sensor voltage. While the engine operates, the controller determines intake manifold pressure and barometric pressure from the MAP sensor voltage. Based on MAP sensor voltage and inputs from other sensors, the engine controller adjusts spark advance, air/fuel mixture and controls the turbocharger wastegate.

The MAP sensor (Fig. 12) mounts underhood on the right side of the engine compartment. The sensor connects electrically to the engine controller.