VW Passat & Audi A4 1990-2000

Distributor Cap and Rotor

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Of the vehicles covered in this guide, only the 2.0L 9A and ABA engines used in the Passat GL/CL models use a distributor and rotor to route the high voltage ignition to the spark plugs. The 1.8L, V6 and VR6 engines have a distributorless ignition system that combines the coil and distributor into a single solid-state unit.

The distributor cap is fitted with a shield for radio interference suppression. Combined with the special suppressors on the spark plug wire terminals, any interference with radio reception is eliminated.

The rotor is pressed onto the distributor shaft, except for 2.0L 16V (9A) engines, which utilize a glued-on rotor to ensure precise spark control. On these engines, the rotor must be destroyed for removal.

Inspection

To inspect the distributor cap, it is not necessary to remove the spark plug wires.

  1. Disengage the two clips that secure the distributor cap to the rotor.
  2.  
  3. Lift the distributor cap (with the wires attached) away from the distributor. Some early models with metal suppression shields have a ground wire that is attached to the side of the distributor; make sure to unplug it before pulling the distributor cap away
  4.  
  5. Note the condition of the inside of the distributor cap. Check the metal terminals for burns, carbon build-up, pitting, cracking, etc. If the distributor cap is worn, it should be replaced to avoid driveability problems.
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  7. Next, check the condition of the rotor. Check for cracks on the sides of the rotor. As with the distributor cap, any excessive pitting, carbon build-up, etc. warrants rotor replacement.
  8.  
  9. When installing the distributor cap, make sure the tab at the base of the cap aligns with the notch on the distributor housing.
  10.  

Distributor rotor resistance:



600-1,400 ohms
 

Removal & installation
  1. Disengage the two clips that secure the distributor cap to the rotor.
  2.  
  3. Lift the distributor cap (with the wires attached) away from the distributor. Some early models with metal suppression shields have a ground wire that is attached to the side of the distributor; make sure to unplug it before pulling the distributor cap away from the distributor.
  4.  
  5. Using a paint marker or other means of identification, label each of the spark plug wires, and their relationship to the distributor cap. Make sure to mark the distributor cap itself, since the suppression shield is a separate component.
  6.  
  7. Once the relationship between the spark plug wires and the distributor cap are labeled, remove the wires from the cap. Make sure not to pull on the wires themselves, or they may be damaged.
  8.  
  9. Separate the suppression shield from the distributor cap.
  10.  
  11. Place the new distributor cap next to the old unit, using the alignment tab on the bottom of the distributor cap to orient them in the same direction. Copy the labels from the old distributor cap onto the new unit.
  12.  
  13. Install the suppression shield onto the new distributor cap.
  14.  
  15. Place a small amount of dielectric grease (usually supplied with the new distributor cap and rotor) on the tip of each wire connector. Using the labels on the wires and distributor cap, install the wires in the proper order.
  16.  
  17. To remove the rotor, carefully squeeze it with pliers to break it up to avoid damage to the distributor shaft. Do NOT hit it with a hammer! Be sure to remove all old adhesive and use the glue that comes with the new part to install the new rotor.
  18.  


NOTE
There are several different types of rotors, which appear similar, but have different resistance values. When replacing the distributor cap and rotor, make sure to obtain the correct parts for your particular vehicle.

  1. Install the distributor cap onto the distributor, making sure the tab at the base of the cap aligns with the notch on the distributor.
  2.  
  3. Secure the clips that hold the cap onto the distributor. If the suppression shield is an older metal type, make sure to attach the ground wire.
  4.  

 
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