Chrysler Front Wheel Drive Cars 6-CYL 1988-1995 Repair Information

Intake Manifold

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REMOVAL & INSTALLATION




CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

3.0L Engines
EXCEPT PREMIER AND MONACO

See Figures 1 through 22

The MPI fuel system is under a constant pressure of about 48 psi (330 kPa). Before servicing the fuel pump, fuel lines, fuel filter, throttle body or fuel injector, the fuel system pressure must be released.

  1. Relieve the fuel system pressure. For more details refer to Fuel System .
  2.  



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Fig. Fig. 1: Ignition coil wire attachments-3.0L engines, except Premier and Monaco

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the throttle body to air cleaner hose.
  6.  
  7. Remove the throttle cable and transaxle kickdown linkage.
  8.  
  9. Remove the Automatic Idle Speed (AIS) motor and the Throttle Position Sensor (TPS) wiring connectors from the throttle body.
  10.  
  11. Remove and label the vacuum hose harness from the throttle body.
  12.  
  13. From the air intake plenum, remove the PCV and brake booster hoses and the EGR tube flange.
  14.  
  15. Disconnect and label the sensor wiring at the intake manifold.
  16.  
  17. Remove the vacuum connections from the air intake plenum vacuum connector.
  18.  
  19. Remove the fuel hoses from the fuel rail.
  20.  


WARNING
Wrap shop towels around hoses to catch any gasoline spillage.

  1. Remove the 8 air intake plenum mounting bolts and remove the plenum.
  2.  
  3. Cover the openings in the lower intake manifold with a rag to prevent any object from falling inside the engine and, thus, requiring removal of the cylinder head to retrieve it.
  4.  
  5. Remove the vacuum hoses from the fuel rail and pressure regulator.
  6.  
  7. Disconnect the fuel injector wiring harness from the engine wiring harness.
  8.  
  9. Remove the fuel pressure regulator mounting bolts and remove the regulator from the fuel rail.
  10.  

Be careful not to damage the rubber injector O-rings upon removal from the ports.

  1. Remove the fuel rail mounting bolts and remove the fuel rail from the intake manifold.
  2.  
  3. Separate the radiator hose from the thermostat housing and the heater hoses from the heater pipe.
  4.  
  5. Remove the 8 intake manifold mounting nuts and washers and remove the manifold from the engine.
  6.  

To install:
  1. Clean the gasket mounting surfaces on the engine and intake manifold. Check the manifold for the following, if installing the used manifold:
    1. Damage and cracks of each section.
    2.  
    3. Clogged water passages in the end cross overs.
    4.  
    5. Check for distortion of the cylinder head and intake plenum mounting surfaces using a straightedge and feeler gauges. The standard for the intake plenum is 0.004 in. (0.15mm) of warpage, or a maximum value of 0.008 in. (0.30mm). The standard for the cylinder head is 0.003 in. (0.10mm) of warpage, or a maximum value of 0.005 in. (0.20 mm).
    6.  

  2.  
  3. Using new gaskets, position the intake manifold on the engine and install the mounting nuts and washers.
  4.  
  5. Tighten the mounting nuts gradually and evenly, in sequence (shown in the illustration), to 15 ft. lbs. (20 Nm).
  6.  



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Fig. Fig. 2: Coolant temperature sensor electrical connections-3.0L engines, except Premier and Monaco



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Fig. Fig. 3: Fuel injector wiring harness connectors-3.0L engines, except Premier and Monaco



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Fig. Fig. 4: First, label and remove the PCV valve hose from the rocker arm cover and valve ...



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Fig. Fig. 5: ... then unbolt the PCV valve from the lower intake manifold



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Fig. Fig. 6: After removing the throttle body, disconnect any residual vacuum lines from the manifold plenum



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Fig. Fig. 7: Loosen and remove the EGR tube flange-to-lower intake manifold mounting bolts ...



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Fig. Fig. 8: ... and remove the EGR tube itself from the intake manifold



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Fig. Fig. 9: Remove and label the vacuum hose from the front of the upper intake manifold plenum ...



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Fig. Fig. 10: ... then label and remove any electrical wires and connectors from the lower manifold



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Fig. Fig. 11: Loosen and remove the upper-to-lower manifold attaching bolts and nuts ...



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Fig. Fig. 12: ... then lift the upper intake manifold plenum up and off of the lower manifold



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Fig. Fig. 13: Disconnect the radiator-to-waterneck coolant hose from the waterneck and ...



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Fig. Fig. 14: ... disconnect the smaller coolant hose from the water box



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Fig. Fig. 15: Loosen and remove the relay bracket-to-lower intake manifold attaching nut, ...



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Fig. Fig. 16: ... unscrew the relay bracket-to-alternator bracket attaching bolt and ...



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Fig. Fig. 17: ... remove the relay and bracket from the engine



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Fig. Fig. 18: Remove the remaining lower intake manifold mounting bolts, then lift the manifold off of the engine



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Fig. Fig. 19: Check the plenum mounting surfaces for warpage-3.0L engines, except Premier and Monaco



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Fig. Fig. 20: Check the intake manifold mounting surface for warpage-3.0L engines, except Premier and Monaco



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Fig. Fig. 21: Nut tightening sequence for the intake manifold-3.0L engines, except Premier and Monaco



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Fig. Fig. 22: Intake plenum tightening sequence-3.0L engines, except Premier and Monaco

  1. Make sure the injector holes are clean. Lubricate the injector O-rings with a drop of clean engine oil and install the injector assembly onto the engine. Make certain that all of the injectors are correctly seated in their bosses, if they are not, remove the injector assembly and reinstall.
  2.  
  3. Install and torque the fuel rail mounting bolts to 10 ft. lbs. (14 Nm).
  4.  
  5. Install the fuel pressure regulator onto the fuel rail and tighten the fuel regulator nuts and bracket bolts to 7.5 ft. lbs. (10 Nm).
  6.  
  7. Install the fuel supply and return tube along with the vacuum crossover hold-down bolt, then tighten to 7.5 ft. lbs. (10 Nm).
  8.  
  9. Connect the fuel injection wiring harness to the engine wiring harness.
  10.  
  11. Connect the vacuum harness to the fuel pressure regulator and fuel rail assembly.
  12.  
  13. Remove the cover from the lower intake manifold and clean the mating surface.
  14.  
  15. Place the intake plenum gasket with the beaded sealant side up, on the intake manifold. Install the air intake plenum and tighten the mounting bolts gradually and evenly, in sequence, to 10 ft. lbs. (14 Nm).
  16.  
  17. Connect the fuel line to the fuel rail and tighten the hose clamps to 10 inch lbs. (1 Nm).
  18.  
  19. Connect the vacuum harness to the air intake plenum.
  20.  
  21. Connect the coolant temperature sensor electrical wiring to the sensor.
  22.  
  23. Connect the PCV and brake booster supply hose to the intake plenum.
  24.  
  25. Plug the AIS and TPS electrical connectors back together.
  26.  
  27. Attach the vacuum vapor harness to the throttle body.
  28.  
  29. Install the throttle cable and transaxle kickdown linkage.
  30.  
  31. Install the air inlet hose assembly.
  32.  
  33. Install the radiator-to-thermostat housing hose and the heater hose to the heater pipe nipple.
  34.  
  35. Refill the cooling system. Connect the negative battery cable.
  36.  
  37. Start the engine as follows: cycle the ignition switch ON and OFF (cranking the engine over) for 4-8 seconds several times to build fuel system pressure, since the fuel system pressure was relieved earlier. After performing this a few times, start the engine and check for fuel, coolant and oil leaks.
  38.  

PREMIER AND MONACO

See Figures 23 through 32

  1. Disconnect the negative (-) battery cable.
  2.  
  3. Remove the engine cover retaining bolts and remove the cover.
  4.  
  5. Remove the air inlet hose from the throttle body.
  6.  
  7. Disconnect the transaxle kickdown cable, accelerator cable and cruise control cable from the throttle body. Remove and label the vacuum hoses from the intake manifold and throttle body.
  8.  


WARNING
Use finger pressure only to remove the cruise control connector. If the connector is broken, the whole cable must be replaced with a new one.

  1. Remove and label the electrical connector from the Throttle Position Sensor (TPS). Remove and label the electrical connectors from the fuel injectors and lay the harness aside.
  2.  
  3. Disconnect the idle air bypass hose from the throttle body. Remove the Hevac reservoir vacuum hose from the fitting on the throttle body adapter.
  4.  



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Fig. Fig. 23: Throttle body bonnet and throttle control cables-early Premier and Monaco



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Fig. Fig. 24: Throttle control cables-late Premier and Monaco



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Fig. Fig. 25: Vacuum hoses, TPS connector, and idle air bypass hose-early Premier and Monaco

  1. Remove the EGR tube and the EGR valve transducer vacuum hose. Remove and label the wire from the air temperature sensor (located behind the idle air bypass hose).
  2.  
  3. Disconnect the Crankcase Ventilation (CCV) vacuum line from the fitting between runners No. 2 and 3.
  4.  
  5. Remove the fuel tank filler cap to relieve the fuel tank pressure.
  6.  
  7. Install the fuel tank filler cap.
  8.  
  9. Place shop towels under the fuel tubes. Disconnect the fuel supply tube from the fuel rail and the fuel return tube from the fuel pressure regulator using the special disconnect tool 6182. Slide the tool onto the nipple and push it forward into the quick connector until the handle stops on the connector casing. Pull the fuel tubes off.
  10.  
  11. Move the tubes to the side being careful not to kink the fuel tubes.
  12.  
  13. Remove the 4 bolts retaining the intake manifold and remove the manifold. Remove the O-rings from the cylinder heads and discard them.
  14.  

When the intake manifold has been removed the O-rings in the cylinder heads must be replaced.

  1. Clean all gasket mating surfaces of oil, dirt and old gasket material.
  2.  



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Fig. Fig. 26: Vacuum hoses, TPS connector and Automatic Idle Speed (AIS) motor connections-late Premier and Monaco



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Fig. Fig. 27: EGR valve transducer vacuum hose-early Premier and Monaco



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Fig. Fig. 28: EGR valve transducer vacuum hose-late Premier and Monaco



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Fig. Fig. 29: Injector harness and CCV vacuum hose

To install:
  1. Use new O-rings and install the intake manifold. Tighten the retaining bolts to 11 ft. lbs. (15 Nm) in an "X'' pattern.
  2.  
  3. Push the fuel supply tube over the fuel rail nipples until a click is heard. Pull back to ensure the connector is locked in place.
  4.  
  5. Push the fuel return tube over the fuel pressure regulator nipples until a click is heard. Pullback to ensure the connector is locked in place.
  6.  
  7. Connect the CCV vacuum hose.
  8.  
  9. Connect the fuel injector wire harness to the injectors.
  10.  
  11. Attach the air temperature sensor wire connector.
  12.  
  13. Connect the Hevac vacuum reservoir hose to the fitting on the throttle body adapter.
  14.  
  15. Connect the air idle bypass hose to the throttle body adapter or Automatic Idle Speed (AIS) motor.
  16.  
  17. Attach the TPS electrical connector.
  18.  
  19. Connect the vacuum hose to the EGR valve transducer.
  20.  
  21. Attach the vacuum connector to the throttle body adapter.
  22.  
  23. Connect the EGR tube.
  24.  
  25. Connect the brake vacuum booster hose.
  26.  
  27. Connect the accelerator cable, cruise control cable, and transaxle kickdown cable.
  28.  
  29. Connect the negative (-) battery cable.
  30.  
  31. Connect the throttle body bonnet or air inlet hose to the throttle body.
  32.  
  33. Cycle the ignition switch ON and OFF (duration of 4-8 seconds) several times to build fuel system pressure. Start the engine and check for coolant, oil, fuel or vacuum leaks.
  34.  



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Fig. Fig. 30: Disconnect the fuel lines using the disconnect special tool 6182



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Fig. Fig. 31: Intake manifold mounting bolts



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Fig. Fig. 32: O-ring locations in the cylinder heads

3.3L and 3.8L Engines

See Figures 33 through 47

  1. Relieve the fuel system pressure. For more details refer to Fuel System .
  2.  



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Fig. Fig. 33: Throttle body assembly-3.3L and 3.8L engines



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Fig. Fig. 34: Throttle cable attachment-3.3L and 3.8L engines



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Fig. Fig. 35: Electrical and vacuum connection to the throttle body-3.3L and 3.8L engines

  1. Remove Automatic Idle Speed (AIS) motor and Throttle Position Sensor (TPS) wiring connectors from the throttle body.
  2.  
  3. Remove the vacuum hose harness from the throttle body.
  4.  
  5. Remove the PCV and brake booster hoses from the air intake plenum.
  6.  
  7. Remove the Exhaust Gas Recirculation (EGR) tube flange from the intake plenum, if so equipped.
  8.  
  9. Unplug the charge temperature sensor electrical connector. Remove the vacuum harness connectors from the intake plenum.
  10.  
  11. Remove the cylinder head-to-intake plenum strut.
  12.  
  13. Disconnect the Manifold Absolute Pressure (MAP) sensor and oxygen (O 2 ) sensor connectors. Remove the engine mounted ground strap.
  14.  
  15. Remove the fuel hose quick-disconnect fittings from the fuel rail using an open end wrench to push in on the plastic ring located on the end of the fittings. Gently pull the fittings from the fuel rail.
  16.  
  17. Remove the Direct Ignition System (DIS) coils and the alternator bracket-to-intake manifold bolt.
  18.  
  19. Remove the upper intake manifold attaching bolts and remove the upper manifold.
  20.  
  21. Cover the openings in the intake manifold to keep debris or loose components from falling into the engine, which would perhaps necessitate dismantling the entire upper end of the engine.
  22.  
  23. Remove the vacuum harness connector from the fuel pressure regulator.
  24.  
  25. Remove the fuel tube retainer bracket screw and fuel rail attaching bolts. Spread the retainer bracket to allow for clearance when removing the fuel tube.
  26.  



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Fig. Fig. 36: Electrical and vacuum connections to the intake manifold-3.3L and 3.8L engines



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Fig. Fig. 37: The MAP sensor electrical connector-3.3L and 3.8L engines



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Fig. Fig. 38: Quick-connect fuel fittings to the fuel rail-3.3L and 3.8L engines



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Fig. Fig. 39: Ignition coil fasteners-3.3L and 3.8L engines

  1. Remove the fuel rail injector wiring clip from the alternator bracket.
  2.  
  3. Disconnect the cam sensor, coolant temperature sensor and engine temperature sensor.
  4.  
  5. Remove the fuel rail. Be careful not to damage the rubber injector O-rings upon removal from their ports.
  6.  
  7. Remove the upper radiator hose, bypass hose and rear intake manifold hose.
  8.  
  9. Remove the intake manifold bolts and remove the manifold from the engine.
  10.  
  11. Remove the intake manifold seal retainer screws and remove the manifold gasket.
  12.  

To install:
  1. Check the components before reassembly for:
    1. Damage and cracks of each section.
    2.  
    3. Clogged water passages in the end crossovers and clogged gas passages.
    4.  

  2.  
  3. Clean and dry all gasket mating surfaces.
  4.  
  5. Place a drop of silicone sealer (about 1 / 4 in./ 6mm) of Mopar® Silicone Rubber Adhesive Sealant or the equivalent, onto each of the 4 manifold-to-cylinder head gasket corners.
  6.  


CAUTION
The intake manifold gasket is composed of very thin and sharp metal. Handle this gasket with care or personal injury could result.

  1. Install the intake manifold gasket and tighten the end seal retainer screws to 10 ft. lbs. (12 Nm).
  2.  
  3. Install the intake manifold and tighten the 8 bolts in sequence to 10 inch lbs. (1 Nm). Repeat the sequence increasing the torque to 17 ft. lbs. (23 Nm) and recheck each bolt for 17 ft. lbs. of torque. After the bolts are tightened, inspect the seals to ensure that they have not become dislodged.
  4.  



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Fig. Fig. 40: Intake manifold bolts-3.3L and 3.8L engines



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Fig. Fig. 41: Fuel rail attaching bolts-3.3L and 3.8L engines



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Fig. Fig. 42: Fuel injector wiring clip-3.3L and 3.8L engines



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Fig. Fig. 43: Fuel rail removal-3.3L and 3.8L engines

  1. Make sure the injector holes are clean and all plugs have been removed.
  2.  
  3. Lubricate the injector O-ring with a drop of clean engine oil to ease the installation.
  4.  
  5. Put the tip of each injector into their ports. Push the assembly into place until the injectors are seated in the ports.
  6.  
  7. Install the four fuel rail attaching bolts and tighten to 16 ft. lbs. (22 Nm).
  8.  
  9. Install the fuel tube retaining bracket screw and tighten to 35 inch lbs. (4 Nm).
  10.  
  11. Reconnect the cam sensor, coolant temperature sensor and engine temperature sensor.
  12.  
  13. Install the fuel rail injector wiring clip on the alternator bracket and the intake manifold water tube.
  14.  
  15. Install the vacuum harness to the pressure regulator.
  16.  
  17. Install the upper intake manifold with a new gasket.
    1. Finger-tighten the bolts.
    2.  
    3. Install the alternator bracket to intake manifold bolt and the cylinder head to intake manifold strut and bolts.
    4.  
    5. Tighten the intake manifold mounting bolts to 21 ft. lbs. (28 Nm) starting from the middle and working outward.
    6.  
    7. Tighten the alternator bracket and strut bolts to 40 ft. lbs. (54 Nm).
    8.  

  18.  
  19. Attach the ground strap, the MAP and the heated O 2 sensor electrical connectors.
  20.  
  21. Attach the charge temperature sensor electrical connector.
  22.  
  23. Attach vacuum harness to the intake plenum.
  24.  
  25. Using a new gasket, connect the EGR tube flange to the intake manifold and tighten to 16 ft. lbs. (22 Nm).
  26.  
  27. Clip the wiring harness into the hole in the throttle cable bracket.
  28.  
  29. Attach the wiring connectors to the TPS and the AIS motor.
  30.  
  31. Connect the vacuum harness to the throttle body.
  32.  



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Fig. Fig. 44: Intake manifold removal and installation-3.3L and 3.8L engines



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Fig. Fig. 45: Intake manifold gasket-3.3L and 3.8L engines



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Fig. Fig. 46: Intake manifold gasket sealing-3.3L and 3.8L engines



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Fig. Fig. 47: EGR tube, heated O2 sensor and alternator/power steering strut-3.3L and 3.8L engines

  1. Install the DIS coils. Tighten the fasteners to 9 ft. lbs. (12 Nm).
  2.  
  3. Lubricate the ends of the chassis fuel tubes with 30-weight oil. Connect the fuel supply and return hoses to the chassis fuel tube assembly. Pull back on the quick-disconnect fitting to ensure complete insertion.
  4.  
  5. Install the throttle cable.
  6.  
  7. Connect the fuel injector wiring harness.
  8.  
  9. Install the air cleaner and hose assembly.
  10.  
  11. Connect the negative battery cable and fill the cooling system with coolant.
  12.  
  13. Start the engine and check for coolant, oil or fuel leaks. The engine may take longer than usual to start, this is because the system will have to pressurize itself.
  14.  

 
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