GM Cadillac Deville_Fleetwood_ELD_Seville 1990-1998

Distributor

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CAUTION
The HEI coil secondary voltage output capabilities can exceed 40,000 volts. Avoid body contact with the HEI high voltage secondary components when the engine is running, or personal injury may result.

The High-Energy Ignition (HEI) distributor with Electronic Spark Control (ESC) combines all necessary ignition components in one contained unit. The system includes:



An integral ignition coil assembly
 
A magnetic pick-up coil and pole piece assembly
 
A Hall Effect switch
 
A solid state ignition module
 
An RFI-suppression capacitor and primary winding harness
 
A distributor cap and rotor
 

All spark timing changes in the HEI (ESC) distributor are performed electronically by the Powertrain Control Module (PCM). The PCM monitors information from various engine sensors, computes the desired spark timing, and signals the distributor to change the timing accordingly. A back up spark advance system is programmed into the ignition module in case of PCM failure. No vacuum or mechanical advance is used.



When making compression checks, disconnect the ignition switch feed wire at the distributor. When detaching this connector, do NOT use a screwdriver or tool to release the locking tabs, as it may break.
 
No periodic lubrication is required. Engine oil lubricates the lower bushing and an oil filled reservoir provides lubrication for the upper bushing.
 
The tachometer (TACH) terminal is next to the ignition switch (BAT) connector on the distributor cap.
 


NOTE
The tachometer terminal must never be allowed to touch ground, as damage to the module and/or ignition coil can result. Some tachometers currently in use may not be compatible with the HEI system used. Consult the manufacturer of the tachometer if a question arises.



Dwell adjustment is controlled by the PCM can not be adjusted.
 
The material used to construct the spark plug cables is very soft. This cable will withstand more heat and carry higher voltage, but scuffing and cutting becomes easier. The spark plug cables must be routed correctly to prevent chaffing or cutting. When removing a spark plug wire from a plug, twist the boot on the spark plug and pull on the boot.
 

REMOVAL & INSTALLATION



During the distributor removal and installation, it is very important that the engine crankshaft not be rotated. If rotated, the reference marks made during removal will have to be disregarded. If the engine is accidentally rotated, the timing will be disturbed. If this is the case, make sure to follow the appropriate distributor installation procedure.

  1. Disconnect the negative battery cable.
  2.  
  3. Label and disconnect all wires leading from the distributor cap.
  4.  



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Fig. Distributor assembly-4.5L and 4.9L engines



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Fig. Detach wire connectors at the distributor cap



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Fig. Distributor wrench J29791

  1. Remove the four bolts from the distributor cap and move the cap out of the way. Note the position of the distributor cap prior to removal.
  2.  


NOTE
Location of the cap doghouse must be in the same area on reinstallation for sufficient clearance for adjustment.

  1. Detach the six terminal connector from the distributor, if not already done.
  2.  
  3. Using a distributor wrench, remove the distributor hold-down nut and clamp.
  4.  
  5. Matchmark the rotor-to-distributor body and the distributor body-to-engine positions. Pull the distributor upward until the rotor just stops turning counterclockwise and again note the position of the rotor. Remove the distributor from the engine.
  6.  


NOTE
A thrust washer is used between the distributor drive gear and the crankcase. This washer may stick to the bottom of the distributor as it is removed from the engine. Before replacing the distributor, verify that the thrust washer is located in the crankcase at the bottom of the distributor bore.

INSTALLATION



Timing Not Disturbed

NOTE
Before installing, visually inspect the distributor. The drive gear should be free of nicks, cracks, and excessive wear. The distributor drive shaft should move freely, without binding. If equipped with an O-ring, it should fit tightly and be free of cuts.

  1. To install the distributor, rotate the distributor shaft until the rotor aligns with the second mark, when the shaft stopped moving. Lubricate the drive gear with clean engine oil and install the distributor into the engine. As the distributor is installed, the rotor should rotate to the first alignment mark; this will ensure proper timing. If the marks do not align properly, remove the distributor and reinstall. Be sure to install the thrust washer on the distributor shaft prior to installation.
  2.  
  3. Install the hold-down clamp and distributor clamp nut. Tighten the nut until the distributor can just be moved with a little effort.
  4.  
  5. Connect the six terminal harness. Install the distributor cap and secure with the four retainer bolts.
  6.  
  7. Connect the coil harness and the ignition switch battery feed wire at the distributor cap.
  8.  
  9. Connect the negative battery cable.
  10.  
  11. Adjust the ignition timing. Once the timing has been adjusted, tighten the distributor hold-down nut to 20 ft. lbs. (25 Nm).
  12.  

Timing Disturbed

If the engine was accidentally cranked after the distributor was removed, the following procedure can be used for distributor installation.

  1. Remove the No. 1 spark plug.
  2.  
  3. Place your finger over No. 1 spark plug hole and crank the engine slowly until compression is felt.
  4.  
  5. Continue cranking slowly until the timing mark on the crankshaft pulley aligns with the 0 degrees on the engine timing indicator. At this point, No. 1 piston is at the TDC of its compression stroke.
  6.  
  7. Position the distributor in the block but do not allow it to engage with the drive gear.
  8.  
  9. Rotate the distributor shaft until the rotor points between No. 1 and No. 8 spark plug towers on the distributor cap. Install the distributor into the engine. If correctly installed, the rotor will point toward the No. 1 tower in the distributor cap when it is fully installed in the engine.
  10.  


NOTE
If installed correctly, the rotor should point toward the No. 1 spark plug tower in the distributor cap. If this is not the case, remove the distributor and reinstall until correct rotor positioning is achieved.

  1. Install the hold-down clamp and tighten the nut until it is snug, do not tighten at this time.
  2.  
  3. Connect the ignition feed wire.
  4.  
  5. Install the distributor cap and spark plug wires.
  6.  
  7. Check the engine timing and adjust as required. Once the timing is set to specifications, tighten the distributor hold-down nut to 20 ft. lbs. (25 Nm).
  8.  


NOTE
Malfunction trouble codes must be cleared after removal or adjustment of the distributor. Refer to clearing trouble codes for the proper procedure.

  1. Installation is the reverse of the removal procedure.
  2.  

 
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