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Fuel System: Other Chrysler Pacifica CS

Fuel System 19 illustrations ~4107 words

INJECTION SYSTEM

All engines used in this section have a sequential Multi-Port Electronic Fuel Injection system. The MPI system is computer regulated and provides precise air/fuel ratios for all driving conditions. The Powertrain Control Module (PCM) operates the fuel injection system.

The PCM regulates

  1. Ignition timing
  2. Air/fuel ratio
  3. Emission control devices
  4. Cooling fan
  5. Charging system
  6. Idle speed
  7. Vehicle speed control

Various sensors provide the inputs necessary for the PCM to correctly operate these systems. In addition to the sensors, various switches also provide inputs to the PCM.

The PCM can adapt its programming to meet changing operating conditions.

Fuel is injected into the intake port above the intake valve in precise metered amounts through electrically operated injectors. The PCM fires the injectors in a specific sequence. Under most operating conditions, the PCM maintains an air fuel ratio of 14.7 parts air to 1 part fuel by constantly adjusting injector pulse width. Injector pulse width is the length of time the injector is open.

The PCM adjusts injector pulse width by opening and closing the ground path to the injector. Engine RPM (speed) and manifold absolute pressure (air density) are the primary inputs that determine injector pulse width.

IGNITION SWITCH ON (ZERO RPM) MODE

When the ignition switch activates the fuel injection system, the following actions occur

  1. The PCM monitors the engine coolant temperature sensor and throttle position sensor input. The PCM determines basic fuel injector pulse width from this input.
  2. The PCM determines atmospheric air pressure from the MAP sensor input to modify injector pulse width.

When the key is in the ON position and the engine is not running (zero rpm), the Auto Shutdown (ASD) and fuel pump relays de-energize after approximately 1 second. Therefore, battery voltage is not supplied to the fuel pump, ignition coil, fuel injectors and heated oxygen sensors.

ENGINE START-UP MODE

This is an OPEN LOOP mode. If the vehicle is in park or neutral (automatic transaxles) or the clutch pedal is depressed (manual transaxles) the ignition switch energizes the starter relay when the engine is not running. The following actions occur when the starter motor is engaged.

  1. If the PCM receives the camshaft position sensor and crankshaft position sensor signals, it energizes the Auto Shutdown (ASD) relay and fuel pump relay. If the PCM does not receive both signals within approximately one second, it will not energize the ASD relay and fuel pump relay. The ASD and fuel pump relays supply battery voltage to the fuel pump, fuel injectors, ignition coil, (EGR solenoid and PCV heater if equipped) and heated oxygen sensors.
  2. The PCM energizes the injectors (on the 69° degree falling edge) for a calculated pulse width until it determines crankshaft position from the camshaft position sensor and crankshaft position sensor signals. The PCM determines crankshaft position within 1 engine revolution.
  3. After determining crankshaft position, the PCM begins energizing the injectors in sequence. It adjusts injector pulse width and controls injector synchronization by turning the individual ground paths to the injectors On and Off.
  4. When the engine idles within +/-64 RPM of its target RPM, the PCM compares current MAP sensor value with the atmospheric pressure value received during the Ignition Switch On (zero RPM) mode.

Once the ASD and fuel pump relays have been energized, the PCM determines injector pulse width based on the following

  1. MAP
  2. Engine RPM
  3. Battery voltage
  4. Engine coolant temperature
  5. Inlet/Intake air temperature (IAT)
  6. Throttle position
  7. The number of engine revolutions since cranking was initiated

During Start-up the PCM maintains ignition timing at 9° BTDC.

ENGINE WARM-UP MODE

This is an OPEN LOOP mode. The following inputs are received by the PCM

  1. Manifold Absolute Pressure (MAP)
  2. Crankshaft position (engine speed)
  3. Engine coolant temperature
  4. Inlet/Intake air temperature (IAT)
  5. Camshaft position
  6. Knock sensor
  7. Throttle position
  8. A/C switch status
  9. Battery voltage
  10. Vehicle speed
  11. Speed control
  12. O2 sensors

The PCM adjusts injector pulse width and controls injector synchronization by turning the individual ground paths to the injectors On and Off.

The PCM adjusts ignition timing and engine idle speed. Engine idle speed is adjusted through the idle air control motor.

CRUISE OR IDLE MODE

When the engine is at operating temperature this is a CLOSED LOOP mode. During cruising or idle the following inputs are received by the PCM

  1. Manifold absolute pressure
  2. Crankshaft position (engine speed)
  3. Inlet/Intake air temperature
  4. Engine coolant temperature
  5. Camshaft position
  6. Knock sensor
  7. Throttle position
  8. Exhaust gas oxygen content (O2 sensors)
  9. A/C switch status
  10. Battery voltage
  11. Vehicle speed

The PCM adjusts injector pulse width and controls injector synchronization by turning the individual ground paths to the injectors On and Off.

The PCM adjusts engine idle speed and ignition timing. The PCM adjusts the air/fuel ratio according to the oxygen content in the exhaust gas (measured by the upstream and downstream heated oxygen sensor).

The PCM monitors for engine misfire. During active misfire and depending on the severity, the PCM either continuously illuminates or flashes the malfunction indicator lamp (Check Engine light on instrument panel). Also, the PCM stores an engine misfire DTC in memory, if 2nd trip with fault.

The PCM performs several diagnostic routines. They include

  1. Oxygen sensor monitor
  2. Downstream heated oxygen sensor diagnostics during open loop operation (except for shorted)
  3. Fuel system monitor
  4. EGR monitor (if equipped)
  5. Purge system monitor
  6. Catalyst efficiency monitor
  7. All inputs monitored for proper voltage range, rationality.
  8. All monitored components (refer to «EMISSIONS CONTROL»(ref-245445) for On-Board Diagnostics).

The PCM compares the upstream and downstream heated oxygen sensor inputs to measure catalytic convertor efficiency. If the catalyst efficiency drops below the minimum acceptable percentage, the PCM stores a diagnostic trouble code in memory, after 2 trips.

During certain idle conditions, the PCM may enter a variable idle speed strategy. During variable idle speed strategy the PCM adjusts engine speed based on the following inputs.

  1. A/C status
  2. Battery voltage
  3. Battery temperature or Calculated Battery Temperature
  4. Engine coolant temperature
  5. Engine run time
  6. Inlet/Intake air temperature
  7. Vehicle mileage

ACCELERATION MODE

This is a CLOSED LOOP mode. The PCM recognizes an abrupt increase in Throttle Position sensor output voltage or MAP sensor output voltage as a demand for increased engine output and vehicle acceleration. The PCM increases injector pulse width in response to increased fuel demand.

  1. Wide Open Throttle-open loop

DECELERATION MODE

This is a CLOSED LOOP mode. During deceleration the following inputs are received by the PCM

  1. A/C status
  2. Battery voltage
  3. Inlet/Intake air temperature
  4. Engine coolant temperature
  5. Crankshaft position (engine speed)
  6. Exhaust gas oxygen content (upstream heated oxygen sensor)
  7. Knock sensor
  8. Manifold absolute pressure
  9. Throttle position sensor
  10. IAC motor (solenoid) control changes in response to MAP sensor feedback

The PCM may receive a closed throttle input from the Throttle Position Sensor (TPS) when it senses an abrupt decrease in manifold pressure. This indicates a hard deceleration (Open Loop). In response, the PCM may momentarily turn off the injectors. This helps improve fuel economy, emissions and engine braking.

WIDE-OPEN-THROTTLE MODE

This is an OPEN LOOP mode. During wide-open-throttle operation, the following inputs are used by the PCM

  1. Inlet/Intake air temperature
  2. Engine coolant temperature
  3. Engine speed
  4. Knock sensor
  5. Manifold absolute pressure
  6. Throttle position

When the PCM senses a wide-open-throttle condition through the Throttle Position Sensor (TPS) it de-energizes the A/C compressor clutch relay. This disables the air conditioning system and disables EGR (if equipped).

The PCM adjusts injector pulse width to supply a predetermined amount of additional fuel, based on MAP and RPM.

IGNITION SWITCH OFF MODE

When the operator turns the ignition switch to the OFF position, the following occurs

  1. All outputs are turned off, unless 02 Heater Monitor test is being run. Refer to the «EMISSIONS CONTROL»(ref-245445) for On-Board Diagnostics.
  2. No inputs are monitored except for the heated oxygen sensors. The PCM monitors the heating elements in the oxygen sensors and then shuts down.

Short Term

The first fuel correction program that begins functioning is the short term fuel correction. This system corrects fuel delivery in direct proportion to the readings from the Upstream O2 Sensor.

The PCM monitors the air/fuel ratio by using the input voltage from the O2 Sensor. When the voltage reaches its preset high or low limit, the PCM begins to add or remove fuel until the sensor reaches its switch point. The short term corrections then begin.

The PCM makes a series of quick changes in the injector pulse-width until the O2 Sensor reaches its opposite preset limit or switch point. The process then repeats itself in the opposite direction.

Short term fuel correction will keep increasing or decreasing injector pulse-width based upon the upstream O2 Sensor input. The maximum range of authority for short term memory is 25% (+/-) of base pulse-width. Short term is violated and is lost when ignition is turned OFF.

Long Term

The second fuel correction program is the long term adaptive memory. In order to maintain correct emission throughout all operating ranges of the engine, a cell structure based on engine rpm and load (MAP) is used.

The number of cells varies upon the driving conditions. Two cells are used only during idle, based upon TPS and Park/Neutral switch inputs. There may be two other cells used for deceleration, based on TPS, engine rpm, and vehicle speed. The other twelve cells represent a manifold pressure and an rpm range. Six of the cells are high rpm and the other six are low rpm. Each of these cells has a specific MAP voltage range Typical Adaptive Memory Fuel Cells .

As the engine enters one of these cells the PCM looks at the amount of short term correction being used. Because the goal is to keep short term at 0 (O2 Sensor switching at 0.5 volt), long term will update in the same direction as short term correction was moving to bring the short term back to 0. Once short term is back at 0, this long term correction factor is stored in memory.

The values stored in long term adaptive memory are used for all operating conditions, including open loop and cold starting. However, the updating of the long term memory occurs after the engine has exceeded approximately 170°-190° F, with fuel control in closed loop and two minutes of engine run time. This is done to prevent any transitional temperature or start-up compensations from corrupting long term fuel correction.

Long term adaptive memory can change the pulse-width by as much as 25%, which means it can correct for all of short term. It is possible to have a problem that would drive long term to 25% and short term to another 25% for a total change of 50% away from base pulse-width calculation.

Open ThrottleOpen ThrottleOpen ThrottleOpen ThrottleOpen ThrottleOpen ThrottleIdleDecel
Vacuum201713950
Above 1,984 rpm135791113 Drive15
Below 1,984 rpm024681012 Neutral14
MAP volt =01.42.02.63.33.9

Typical Adaptive Memory Fuel Cells

3.5L

The crankshaft sensor is located on the driver side of the vehicle. see scheme 96, above the differential housing. The bottom of the sensor sits above the drive plate.

Scheme 75

Scheme 75: 3.5L
Scheme 75: 3.5L
  1. Disconnect the negative and positive battery cable.
  2. Remove the battery.
  3. Unlock and disconnect electrical connector from crankshaft position sensor.
  4. Remove sensor mounting screw. Remove sensor.

3.8L

The crankshaft sensor is located on the driver side of the vehicle. see scheme 97, above the differential housing. The bottom of the sensor sits above the drive plate.

Scheme 76

Scheme 76: 3.8L
Scheme 76: 3.8L
  1. Disconnect the negative and positive battery cable.
  2. Remove the battery.
  3. Unlock and disconnect electrical connector from crankshaft position sensor.
  4. Remove sensor mounting screw. Remove sensor.

Scheme 77

Scheme 77: 3.5L
Scheme 77: 3.5L
  1. Install sensor and push sensor down until contact is made with the transmission case. see scheme 98 While holding the sensor in this position, install and tighten the retaining bolt to 12 N.m (105 in. lbs.) torque.
  2. Connect electrical connector and lock to crankshaft position sensor.
  3. Install battery.
  4. Connect the positive then the negative battery cable.
  1. Install sensor and push sensor down until contact is made with the transmission case. see scheme 99 While holding the sensor in this position, install and tighten the retaining bolt to 12 N.m (105 in. lbs.) torque.
  2. Connect electrical connector and lock to crankshaft position sensor.
  3. Install battery.
  4. Connect the positive then the negative battery cable.
  1. Release fuel pressure, refer to «STANDARD PROCEDURE - FUEL SYSTEM PRESSURE RELEASE PROCEDURE»(ref-245444-S00253154212006110200000).
  2. Disconnect the negative battery cable.
  3. Remove the upper intake manifold. (Refer to «INTAKE MANIFOLD»(ref-245454-S15097980062006110200000) ).
  4. If the injector connectors are not tagged with their cylinder number, tag them to identify the correct cylinder.
  5. Disconnect the fuel supply line from the fuel rail. see scheme 100
  6. Remove the 4 mounting bolts from the fuel rail. see scheme 101
  7. Lift fuel rail straight up off of cylinder head.
  8. Remove retaining clips from fuel injectors at fuel rail.
  9. Remove fuel injector from fuel rail.
  1. Lightly lubricate the fuel injector O-rings with a couple drops of clean engine oil. see scheme 113
  2. Install retaining clips on fuel injectors.
  3. Push injectors into fuel injector rail until clips are in the correct position. see scheme 114
  4. Position fuel rail over cylinder heads, and push rail into place. Tighten fuel rail mounting bolts to 28 N.m (250 in. lbs.) torque. see scheme 115
  5. Connect the fuel supply tube quick connect fitting to the fuel rail. see scheme 116
  6. Connect the electrical connectors to the fuel injectors.
  7. Install intake manifold plenum. (Refer to «INTAKE MANIFOLD»(ref-245454-S15097980062006110200000) ).
  8. Connect negative cable to battery.
  1. Inspect and replace damaged fuel injector O-rings. see scheme 117
  2. Lightly lubricate the fuel injector O-rings with a couple drops of clean engine oil.
  3. Install retaining clips on fuel injectors. see scheme 118
  4. Fuel injector locator flange on fuel rail. see scheme 119
  5. Push injectors into fuel injector rail until clips are in the correct position. see scheme 120
  6. Fuel injector installed into fuel rail in the correct position. see scheme 121
  7. Fuel rail with injectors installed. see scheme 122
  8. Position fuel rail over cylinder heads, and push rail into place. see scheme 123 Tighten fuel rail mounting bolts to 28 N.m (250 in. lbs.) torque.
  9. Connect the electrical connectors to the fuel injectors and lock. see scheme 54
  10. Connect the fuel supply tube quick connect fitting to the fuel rail. see scheme 125
  11. Inspect the intake manifold gaskets. see scheme 126
  12. Intake manifold gaskets installed. (Scheme 78)
  13. Install intake manifold plenum. see scheme 128, (Refer to «INTAKE MANIFOLD»(ref-245455-S42568962102006110200000) ).
  14. Connect and lock the electrical for the MAP sensor (1).
  15. Connect the vacuum lines (2). see scheme 59 1 - MAP Sensor 2 - Vacuum Lines
  16. Connect the electrical connector for Throttle Position Sensor (2), Idle Air Control Motor (3). see scheme 60 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  17. Connect the purge line (1).
  18. Connect negative cable to battery.

Scheme 78

Scheme 78: 3.5L
Scheme 78: 3.5L
  1. Disconnect the negative battery cable.
  2. Disconnect the IAC electrical connector. see scheme 131
  3. Remove the IAC mounting screws.
  4. Remove the IAC.
  1. Disconnect negative battery cable.
  2. Unlock and disconnect electrical connector from Idle Air Control Motor (IAC). see scheme 132 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  3. Remove IAC monting bolt.
  4. Remove IAC from throttle body.

When servicing throttle body components, always reassemble components with new O-rings and seals where applicable. If assembly of component is difficult, a light coat of engine oil may be applied to the O-RINGS ONLY. see scheme 133to aid assembly.

Scheme 79

Scheme 79: 3.5L
Scheme 79: 3.5L
1 - O-rings
  1. Install the IAC to the throttle body. see scheme 134
  2. Tighten mounting screw to 5.5 N.m (49 in. lbs.) torque.
  3. Attach electrical connector to the IAC.
  4. Connect the negative battery cable.

When servicing throttle body components, always reassemble components with new O-rings and seals where applicable. If assembly of component is difficult, a light coat of engine oil may be applied to the O-RINGS ONLY. see scheme 135to aid assembly.

1 - O-rings
  1. The new idle air control motor has a new O-ring installed on it.
  2. Carefully place idle air control motor into throttle body. see scheme 136 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  3. Install mounting screw(s). Tighten mounting screw to 5.5 N.m (49 in. lbs.) torque.
  4. Connect electrical connector to idle air control motor.
  5. Connect negative cable to battery.
  1. Disconnect negative battery cable.
  2. Unlock and disconnect electrical connector. (Scheme 80) 1 - MAP Sensor 2 - Vacuum Lines
  3. Remove 2 mounting screws.
  4. Remove sensor.
  1. The sensor mounts onto intake manifold plenum. (Scheme 81) Tighten screws to 4.5 N.m (40 in. lbs.) torque.
  2. Attach electrical connector to sensor. (Scheme 82)
  3. Install the negative battery cable.

When servicing components, always reassemble components with new O-rings and seals where applicable. If assembly of component is difficult, a light coat of engine oil may be applied to the O-RINGS ONLY to aid assembly.

  1. Install MAP sensor. (Scheme 83) 1 - MAP Sensor 2 - Vacuum Lines
  2. Install and tighten screws.
  3. Connect and lock electrical connector.
  4. Connect negative battery cable.

3.8L - UPPER O2 SENSOR

The engines uses two heated oxygen sensors.

CAUTIONWhen disconnecting the sensor electrical connector, do not pull directly on wire going into sensor.

Scheme 80

Scheme 80
Scheme 80

Scheme 81

Scheme 81
Scheme 81
  1. Disconnect negative battery cable.
  2. Disconnect the upper O2 sensor connector. see scheme 150
  3. Use a socket such as Snap-On YA8875 or a crow foot wrench to remove oxygen sensor. see scheme 151 1 - Item_1xftjhxfdj 2 - Item _2tjsryjy

3.8L - LOWER O2 SENSOR

The engines uses two heated oxygen sensors.

CAUTIONWhen disconnecting the sensor electrical connector, do not pull directly on wire going into sensor.

Scheme 82

Scheme 82
Scheme 82
  1. Disconnect negative battery cable.
  2. Raise and support vehicle.
  3. Disconnect the electrical connector.
  4. Use a socket such as Snap-On YA8875 or a crow foot wrench to remove oxygen sensor. see scheme 152

Note. When replacing an O2 Sensor, the PCM RAM memory must be cleared, either by disconnecting the PCM C-1 connector or momentarily disconnecting the Battery negative terminal. The NGC learns the characteristics of each O2 heater element and these old values should be cleared when installing a new O2 sensor. The customer may experience driveability issues if this is not performed.

Scheme 83

Scheme 83: 3.5L
Scheme 83: 3.5L

Scheme 84

Scheme 84
Scheme 84
  1. After removing the sensor, the threads must be cleaned with an 18 mm X 1.5 + 6E tap. If reusing the original sensor, coat the sensor threads with an anti-seize compound such as Loctite 771- 64 or equivalent. New sensors have compound on the threads and do not require an additional coating. Tighten the sensor to 28 N.m (20 ft. lbs.) torque.
  2. Connect the heated oxygen sensor electrical connector.
  3. Install the wiring clip to the heat shield. (Scheme 86)
  4. Connect the negative battery cable.

3.8L - O2 SENSOR UPPER

Note. When replacing an O2 Sensor, the PCM RAM memory must be cleared, either by disconnecting the PCM C-1 connector or momentarily disconnecting the Battery negative terminal. The NGC learns the characteristics of each O2 heater element and these old values should be cleared when installing a new O2 sensor. The customer may experience driveability issues if this is not performed.

  1. After removing the sensor, the threads must be cleaned with an 18 mm X 1.5 + 6E tap. If reusing the original sensor, coat the sensor threads with an anti-seize compound such as Loctite 771- 64 or equivalent. New sensors have compound on the threads and do not require an additional coating. Tighten the sensor to 28 N.m (20 ft. lbs.) torque. (Scheme 87) 1 - Item_1xftjhxfdj 2 - Item _2tjsryjy
  2. Connect the heated oxygen sensor electrical connector. see scheme 156
  3. Connect the negative battery cable.

3.8L - O2 SENSOR LOWER

Note. When replacing an O2 Sensor, the PCM RAM memory must be cleared, either by disconnecting the PCM C-1 connector or momentarily disconnecting the Battery negative terminal. The NGC learns the characteristics of each O2 heater element and these old values should be cleared when installing a new O2 sensor. The customer may experience driveability issues if this is not performed.

  1. After removing the sensor, the threads must be cleaned with an 18 mm X 1.5 + 6E tap. If reusing the original sensor, coat the sensor threads with an anti-seize compound such as Loctite 771- 64 or equivalent. New sensors have compound on the threads and do not require an additional coating. Tighten the sensor to 28 N.m (20 ft. lbs.) torque.
  2. Connect the heated oxygen sensor electrical connector. see scheme 157
  3. Lower vehicle.
  4. Connect the negative battery cable.

Scheme 85

Scheme 85: 3.5L
Scheme 85: 3.5L

Scheme 86

Scheme 86
Scheme 86

Scheme 87

Scheme 87
Scheme 87
  1. Disconnect negative cable from battery
  2. Remove the engine cover.
  3. Remove the air cleaner box, (Refer to «HOUSING-AIR CLEANER»(ref-245454-S16653029582006110200000) ).
  4. Hold throttle lever in wide open position. Remove throttle cable and speed control cables from throttle arm.
  5. Remove throttle cable bracket. see scheme 158
  6. Disconnect electrical connectors from throttle body. (Scheme 88) 1 - Throttle Body 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  7. Remove 3 throttle body bolts.
  8. Remove throttle body. see scheme 160
  9. Clean mating surfaces.

Scheme 88

Scheme 88
Scheme 88
  1. Disconnect negative cable from battery
  2. Remove the air cleaner box, (Refer to «AIR CLEANER HOUSING»(ref-245455-S35224362002006110200000) ).
  3. Remove throttle and speed control cables. see scheme 161
  4. Hold throttle lever in wide open position. Remove throttle cable and speed control cables from throttle arm. see scheme 162
  5. Disconnect electrical connectors and purge line from throttle body. see scheme 163 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  6. Remove 3 throttle body bolts.
  7. Remove throttle body. (Scheme 89)
  8. Clean mating surfaces.
  1. Inspect and replace throttle body gasket if necessary.
  2. Install throttle body gasket.
  3. Install throttle body. see scheme 165
  4. Install 3 throttle body bolts and tighten.
  5. Connect electrical connectors to throttle body. see scheme 166 1 - Throttle Body 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  6. Install throttle cable bracket. (Scheme 90)
  7. Hold throttle lever in wide open position. Install throttle cable and speed control cables to throttle arm.
  8. Install the air cleaner box
  9. Install the engine cover.
  10. Connect negative cable from battery.

Scheme 89

Scheme 89
Scheme 89
  1. Inspect and replace throttle body gasket if necessary.
  2. Install throttle body gasket. see scheme 168
  3. Install throttle body. see scheme 169
  4. Install 3 throttle body bolts and tighten.
  5. Connect electrical connectors and purge line to throttle body. see scheme 170 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  6. Hold throttle lever in wide open position. Install throttle cable and speed control cables to throttle arm. (Scheme 91)
  7. Install the air cleaner box
  8. Install the engine cover.
  9. Connect negative cable from battery.

Scheme 90

Scheme 90: 3.5L
Scheme 90: 3.5L
  1. Disconnect the negative battery cable.
  2. Disconnect the TPS (2) electrical connector. (Scheme 92) 1 - Idle Air Control Motor 2 - Throttle Position Sensor
  3. Remove the TPS (2) mounting screws.
  4. Remove the TPS (2).
  1. Disconnect the negative battery cable.
  2. Disconnect the TPS (2) electrical connector. (Scheme 93) 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  3. Remove the TPS (2) mounting screws.
  4. Remove the TPS (2).
  1. The throttle shaft end of the throttle body slides into a socket in the TPS. The socket has two tabs inside it. The throttle shaft rests against the tabs. When indexed correctly, the TPS can rotate clockwise a few degrees to line up the mounting screw holes with the screw holes in the throttle body. The TPS has slight tension when rotated into position. If it is difficult to rotate the TPS into position, install the sensor with the throttle shaft on the other side of the tabs in the socket. Tighten mounting screws to 5.1 N.m (45 in. lbs.) torque.
  2. After installing the TPS (2), the throttle plate should be closed. If the throttle plate is open, install the sensor on the other side of the tabs in the socket.
  3. Attach electrical connector to the TPS (2). see scheme 174 1 - Idle Air Control Motor 2 - Throttle Position Sensor
  4. Connect the negative battery cable.
  1. The throttle shaft end of the throttle body slides into a socket in the TPS. The socket has two tabs inside it. The throttle shaft rests against the tabs. When indexed correctly, the TPS can rotate clockwise a few degrees to line up the mounting screw holes with the screw holes in the throttle body. The TPS has slight tension when rotated into position. If it is difficult to rotate the TPS into position, install the sensor with the throttle shaft on the other side of the tabs in the socket. Tighten mounting screws to 5.1 N.m (45 in. lbs.) torque.
  2. After installing the TPS (2), the throttle plate should be closed. If the throttle plate is open, install the sensor on the other side of the tabs in the socket.
  3. Attach electrical connector to the TPS (2). see scheme 175 1 - Purge Line 2 - Throttle Position Sensor 3 - Idle Air Control Motor
  4. Connect the negative battery cable.

Scheme 91

Scheme 91: REMOVAL
Scheme 91: REMOVAL

Scheme 92

Scheme 92
Scheme 92

Scheme 93

Scheme 93
Scheme 93
  1. Disconnect the negative battery cable.
  2. Disconnect the electrical connector from the short runner valve. see scheme 176
  3. Remove the link from short runner valve lever. see scheme 177
  4. Remove the 4 bolts.
  5. Remove short runner valve. see scheme 178

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