GM Buick/Oldsmobile/Pontiac/Full-Size 1975-1990 Repair Guide

Component Replacement

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INTERNAL IGNITION COIL



See Figures 1, 2 and 3



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Fig. Fig. 1: To gain access to the internal coil, first disconnect the feed and module wires. Note: Spark plug wires were removed for illustration purposes only, this will be unnecessary during actual service



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Fig. Fig. 2: Removing the coil attaching screws



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Fig. Fig. 3: Remove the coil cover from the distributor cap

  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the feed and module wire terminal connectors from the distributor cap.
  4.  
  5. Remove the ignition set retainer.
  6.  
  7. Remove the 4 coil cover-to-distributor cap screws and the coil cover.
  8.  
  9. Using a blunt drift, press the coil wire spade terminals up out of distributor cap.
  10.  
  11. Lift the coil up out of the distributor cap.
  12.  
  13. Remove and clean the coil spring, rubber seal washer and coil cavity of the distributor cap.
  14.  

To install:
  1. Coat the rubber seal with a dielectric lubricant furnished in the replacement ignition coil package.
  2.  
  3. Install the coil spring, coil assembly and press the coil terminals into the distributor cap. Refer to the coil terminal illustration for terminal location.
  4.  
  5. Install the coil cover and torque the attaching screws to 60 inch lbs. (6 Nm).
  6.  
  7. Position the spark plug wire and retainer over the correct cap terminals, then engage the retainer and plug wires to the cap. Attach the distributor feed wires and negative battery cable.
  8.  

DISTRIBUTOR CAP



See Figures 4 and 5

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner, feed and module wire terminal connectors from the distributor cap.
  4.  
  5. Remove the retainer and spark plug wires from the cap. Remember to label them first.
  6.  
  7. Depress and release the 4 distributor cap-to-housing retainers and lift off the cap assembly.
  8.  
  9. Remove the four coil cover screws and cover.
  10.  
  11. Using a finger or a blunt drift, push the coil spade terminals up out of the distributor cap.
  12.  
  13. Remove all four coil screws and lift the coil, coil spring and rubber seal washer out of the cap coil cavity.
  14.  
  15. Using a new distributor cap, reverse the above procedures to assemble being sure to clean and lubricate the rubber seal washer with dielectric lubricant. Torque the coil cover attaching screws to 60 inch lbs. (6 Nm). Make sure the spark plug wire retainer and the four cap-to-housing retainers are fully engaged. Connect the negative battery cable.
  16.  



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Fig. Fig. 4: Push down and twist the retainers to release the distributor cap, be sure to label the cap and wires to ease installation



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Fig. Fig. 5: Once all four retainers have been released, the distributor cap can be removed

ROTOR



See Figures 6 and 7

  1. Disconnect the negative battery cable and remove the air cleaner assembly.
  2.  
  3. Disconnect the feed and module wire connectors from the distributor.
  4.  
  5. Depress and release the 4 distributor cap-to-housing retainers and lift off the cap assembly.
  6.  
  7. Remove the two rotor attaching screws and rotor.
  8.  
  9. Install the rotor, make sure the square shaft tab is properly engaged with the rotor and torque the retaining screws to 60 inch lbs. (6 Nm). Reinstall the cap and connect the negative battery cable.
  10.  



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Fig. Fig. 6: Removing the rotor attaching screws



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Fig. Fig. 7: Lift the rotor straight up after removing the attaching screws

VACUUM ADVANCE UNIT



1975-80
  1. Disconnect the negative battery cable and remove the air cleaner. Remove the distributor cap and rotor as previously described.
  2.  
  3. Disconnect the vacuum hose from the vacuum advance unit.
  4.  
  5. Remove the two vacuum advance retaining screws, pull the advance unit outward, rotate and disengage the operating rod from its tang.
  6.  
  7. Install the vacuum advance and engage the operating rod, torque the screws to 60 inch lbs. (6 Nm) and install the distributor cap.
  8.  
  9. Install the air cleaner and connect the negative battery cable.
  10.  

MODULE



See Figures 8 and 9

  1. Disconnect the negative battery cable. Remove the air cleaner.
  2.  
  3. Remove the distributor cap and rotor as previously described.
  4.  
  5. Disconnect the harness connector and pick-up coil spade connectors from the module. Be careful not to damage the wires when removing the connector.
  6.  
  7. Remove the two screws and module from the distributor housing.
  8.  
  9. Coat the bottom of the new module with dielectric silicone lubricant supplied with the new module.
  10.  



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Fig. Fig. 8: Be sure to coat the mating surfaces of the module

To install:

The silicone lubricant supplied with new modules MUST be applied, as it serves as a heat conductor and aids in module cooling. Running the engine and ignition system without the silicone lubricant is the equivalent of running the engine without antifreeze! That is, the module will cook itself without the lubricant!

  1. Install the module and torque the retaining screws to 48 inch lbs. (5 Nm).
  2.  
  3. Connect the module wiring harnesses and install the distributor cap.
  4.  
  5. Connect the negative battery cable and install the air cleaner.
  6.  



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Fig. Fig. 9: Disconnecting the module connector

PICK-UP COIL



See Figures 10, 11, 12 and 13

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Mark the base of the distributor and the position of the rotor-to-housing. Remove the distributor-to-engine block retainer and bolt. Make sure the distributor base is marked with a scribe or grease pen for proper timing after installation.
  6.  
  7. Remove the distributor cap and disconnect the cap harnesses.
  8.  
  9. Twist and pull upward to remove the distributor assembly from the block.
  10.  
  11. Mark the distributor shaft and gear so they can be reassembled in the position.
  12.  
  13. Drive out the roll pin with a flat punch or equivalent.
  14.  



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Fig. Fig. 10: Removing distributor roll-pin.

  1. Remove the gear and pull the shaft out of the distributor housing.
  2.  
  3. Disconnect the pick-up harness.
  4.  
  5. Remove the three pick-up coil attaching screws and remove the magnetic shield, C washer, pick-up coil, magnet and pole piece.
  6.  



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Fig. Fig. 11: Pick-up coil removed and disassembled

To install:
  1. Install the pick-up coil so wires go through the opening provided.
  2.  
  3. Install the magnet, pole piece and torque the three screws to 50 inch lbs. (5 Nm).
  4.  
  5. Clean the shaft with solvent to remove the varnish to ease installation.
  6.  
  7. Install the C washer, shaft, gear and tap in the roll pin. Make sure the marks are lined up. Connect the pick-up wiring harness.
  8.  
  9. Install the distributor into the block at the original marked
  10.  

position.


WARNING
Make sure the distributor seats into the block fully. The base of the housing will stick up about1/4of an inch until the distributor gear engages the oil pump drive. Damage to the oil pump, distributor and engine may result if the distributor is forced into position by tightening the distributor retainer bolt. If the distributor will not fully seat, grab the housing and shaft, twist and wiggle until the distributor drops into the oil pump drive. If this does not work, install a socket wrench onto the large bolt on the front of the crankshaft pulley. Slowly turn the crankshaft in either direction until the distributor drops into the block fully.

  1. Install the distributor and retainer. Hand tighten the bolt at this time.
  2.  
  3. Install the distributor cap, connect the wiring harness and negative battery cable.
  4.  
  5. Plug all disconnected vacuum lines, install a inductive timing light and adjust the timing to specifications. Refer to the underhood sticker and timing procedures in this section for more information.
  6.  
  7. Install the air cleaner and connect the vacuum hoses.
  8.  



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Fig. Fig. 12: Removing the distributor hold-down bolt



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Fig. Fig. 13: After removing the distributor, be sure to mark the gear and distributor shaft

 
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