GM Astro/Safari 1985-1996 Repair Guide

Distributor Cap and Rotor

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At every tune-up/inspection, visually check the distributor cap and rotor for damage, burns or corrosion. Check the spark plug towers and their terminals under the cap to make sure they are free of corrosion which would inhibit proper spark distribution. Replace any damaged or worn components.

If the spark plug wires have become unserviceable due to time and wear, it is probably a good idea to replace the cap and rotor as well.

REMOVAL & INSTALLATION



See Figures 1, 2, 3, 4 and 5



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Fig. Fig. 1: Tag all spark plug wires and matching cap terminals before removal



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Fig. Fig. 2: Release the distributor cap hold-down bolts



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Fig. Fig. 3: Remove the cap for inspection, replacement or access to the rotor



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Fig. Fig. 4: Carefully pull the rotor from the distributor shaft-note this type does NOT use retaining screws



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Fig. Fig. 5: Some early-model distributors may have the ignition coil mounted to the distributor cap.

  1. Disconnect the negative battery cable for safety.
  2.  
  3. Remove the engine cover from the passenger compartment.
  4.  

Some late-model vehicles, such as 1996 engines with the HVS system, use spark plug wires and distributor caps which are already numbered for ease of service, BUT double-check this before disconnecting any wires.

  1. If the cap is being completely removed (for replacement or for engine service) TAG all of the spark plug wires and matching terminals on the cap, then disconnect the wires.
  2.  

If the cap is just being removed for inspection or for access to the rotor, it may be possible to remove the cap without disconnecting any/all of the wires and position it aside. Just remember that if you change your mind and disconnect 2 or more wires you MUST stop and tag them before proceeding.

  1. Release the distributor cap retainers. For most vehicles covered by this guide, there should be 2 retaining screws (one on either side of the cap), though some models may use spring loaded cap retainers which are simply twisted 1 / 4 - 1 / 2 turn to release.
  2.  
  3. Remove the cap from the distributor assembly.
  4.  
  5. If you are replacing or inspecting the rotor, check for any retaining screws and remove, if present. Most vans covered by this guide utilize keyed rotor which is mounted to the distributor shaft with a gentle interference fit. Grasp the rotor and gently pull upward to remove it from the shaft.
  6.  
  7. Check the distributor cap and rotor for wear or damage and replace, if necessary.
  8.  

To install:
  1. If removed, install the rotor to the top of the distributor shaft.
  2.  
  3. Install the cap to the distributor assembly. Some early models may utilize an internal-coil type distributor cap. Obviously, the old coil must be transferred to the new cap if you are replacing the cap on these models.
  4.  
  5. As tagged, connect any spark plug wires which were removed.
  6.  
  7. Install the engine cover.
  8.  
  9. Connect the negative battery cable.
  10.  

 
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