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    Mazda 323/626/929/GLC/MX-6/RX-7 1978-1989

    Breaker Points and Condenser

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    Many piston engines are equipped with breaker point distributors through 1979. Although most GLC models used a breakerless distributor as of 1977, the 1977-78 models built for California and Canada, as well as 1979 Canadian models, did utilize breaker point systems. All other 1979 and later models are equipped with a breakerless ignition. On the breakerless distributors, there are no points or condenser to replace.

    The 1979 RX-7 is the only RX-7 model equipped with breaker points and condensers. 1980-89 RX-7 models have electronic ignitions in which no breaker points are needed. The 1979 model has a single distributor which contains two sets of points (leading and trailing). Be sure to check both sets when performing a tune-up.

    CHECKING BREAKER ARM SPRING TENSION



    See Figure 1

    Remove the distributor cap and hook a spring scale to the contact arm as shown in the illustration. Make sure the spring scale is as close as possible to the moveable breaker point and measure how much pressure it takes to separate the points. The points should start to separate at between 1.1-1.4 lbs. (0.50-0.65 kg). If not, the contact arm spring is too weak and the breaker points should be replaced.



    Click image to see an enlarged view

    Fig. Fig. 1: Measure breaker arm spring tension with a spring scale-1979 RX-7 shown

    REMOVAL & INSTALLATION



    Although lightly pitted points may be cleaned with a point file, a new set of points and new condenser should be installed every 12 months or 10,000 miles (16,100 km).

    The condenser capacity is 0.27 mfd (micro-Farads).

    Except 1979 RX-7
    1. Unfasten the clips and remove the distributor cap. Leave the ignition cables attached to the cap.
    2.  
    3. Remove the rotor from the distributor.
    4.  
    5. Unplug the blade type electrical connector from the contact set (breaker points).
    6.  
    7. Remove the two mounting screws, noting the location of any condenser lead. Unfasten the condenser lead terminal and remove the contact set.
    8.  
    9. Unfasten the condenser retaining screw located on the outside of the distributor housing, and remove the condenser.
    10.  

    The smaller condenser, mounted next to the ignition condenser, is for radio noise suppression. It need only be replaced if a clicking sound is heard over the radio.

    To install:
    1. Attach the new condenser to the distributor housing.
    2.  
    3. Install the new contact set, the condenser lead terminal, and the screws. Tighten the screws just enough to hold the contact set in place.
    4.  
    5. Reattach the blade connector to the contact set.
    6.  

    The following step covers adjustment of the ignition points after replacement or cleaning. See the DWELL ANGLE ADJUSTMENT procedure, later in this section, for checking and fine-tuning the adjustment with an electronic dwell meter.

    1. Adjust the point gap as follows:
      1. Rotate the engine by using a remote starter switch, or have someone inside the car operate the ignition key to "bump the starter" until the rubbing block is at the top of the cam.
      2.  
      3. Check the point gap with a feeler gauge. The gap should be 0.020 in. (0.50mm).
      4.  
      5. Adjust the gap with a screwdriver. Loosen the lockscrew just enough to permit the stationary contact to be moved, using the screwdriver as a lever in the slot provided. The lockscrew must be tight enough, however, to hold the stationary contact in one place while you adjust it. Use a clean, flat type feeler gauge to check the gap, and make sure the blade is sliding straight through the gap, not at an angle. Recheck the gap after tightening the lockscrew to make sure the gap has not changed, and readjust as necessary.
      6.  

    2.  
    3. Make sure that the cam follower is properly lubricated. If necessary, wipe dirty grease off the follower and cam, then apply contact point lubricant with a high melting point to the leading edge of the cam follower and cam.
    4.  
    5. Install the rotor and distributor cap.
    6.  
    7. Check and adjust the dwell angle, as necessary.
    8.  

    1979 RX-7

    See Figure 2

    1. Unsnap the clips and remove the distributor cap. Remove the rotor.
    2.  
    3. Unplug the blade type connector from the set of leading points.
    4.  
    5. Remove the mounting screw (or "set screw") which retains the leading set of breaker points and note the position of any condenser wire. Unfasten the condenser lead terminal, if applicable, and remove the point set.
    6.  
    7. Install a new leading set of breaker points, making sure the points fit over any mounting dowels. Install the mounting screw with its wire and tighten.
    8.  
    9. Unplug the blade type connector from the set of trailing points.
    10.  
    11. Remove the mounting screw (or "set screw") which retains the trailing set of breaker points and note the position of any condenser wire. Unfasten the condenser lead terminal, if applicable, and remove the point set.
    12.  
    13. Install a new trailing set of breaker points, making sure the points fit over any mounting dowels. Install the mounting screw with its wire and tighten.
    14.  



    Click image to see an enlarged view

    Fig. Fig. 2: The 1979 RX-7 distributor contains leading and trailing breaker point sets

    1. Unfasten the condenser retaining screw(s) located on the outside of the distributor housing, and remove the condenser(s).
    2.  

    The smaller condenser, mounted near the ignition condenser(s), is for radio noise suppression. It need only be replaced if a clicking sound is heard over the radio.

    1. Attach the new condenser(s) to the distributor housing, then attach the condenser lead terminal(s) to the contact set(s).
    2.  

    The following step covers adjustment of the ignition points after replacement or cleaning. See the DWELL ANGLE ADJUSTMENT procedure, later in this section, for checking and fine-tuning the adjustment with an electronic dwell meter.

    1. Adjust the point gap of each contact set as follows:
      1. Rotate the engine using a remote starter switch, or have someone inside the car operate the ignition key to "bump the starter" until the rubbing block on the leading set of points is at the top of the cam.
      2.  
      3. Check the point gap with a feeler gauge. The gap should be 0.016-0.020 in. (0.40-0.50mm).
      4.  
      5. Adjust the point gap with a screwdriver. Loosen the set screw just enough to permit the stationary contact to be moved, then use the screwdriver as a lever. The set screw must be tight enough, however, to hold the stationary contact in one place while you adjust it. Use a clean flat bladed feeler gauge to check the gap, and make sure the blade slides straight through the gap, not at an angle. Recheck the gap after tightening the set screw to make sure the gap didn't change. A good idea is to use a second screwdriver to tighten the set screw while keeping the first screwdriver on the stationary contact to prevent the gap from changing.
      6.  

    2.  
    3. Make sure that the rubbing block cam is properly lubricated. If necessary, wipe dirty grease off the cam and rubbing block, then apply contact point lubricant with a high melting point to the contact surfaces of these components.
    4.  
    5. Install the rotor and distributor cap.
    6.  
    7. Check and adjust the dwell angle, as necessary.
    8.  

    DWELL ANGLE ADJUSTMENT



    The dwell angle or cam angle is the number of degrees that the distributor cam rotates while the points are closed. There is an inverse relationship between dwell angle and point gap. Increasing the point gap will decrease the dwell angle and vice versa. Checking the dwell angle with a meter is a far more accurate method of measuring point opening than the feeler gauge method.

    Except 1979 RX-7
    1. Start the engine and run it at idle speed, until it reaches normal operating temperature.
    2.  


    CAUTION
    NEVER run the engine in an unventilated area such as a closed garage. Make sure the doors are open and there is adequate airflow. If possible use fans to provide additional air.

    1. Connect a dwell meter to the ignition coil as described in the tool manufacturer's instructions. Read the dwell and compare the reading to the figure shown in the Tune-Up Specifications charts in this section.
    2.  
    3. If dwell is incorrect, stop the engine, remove the distributor cap and rotor, then adjust the point gap as previously described. If the dwell reading is too high, open the point gap slightly; if the dwell reading is too low, close the point gap slightly.
    4.  
    5. After contact point adjustment, replace the cap and rotor, start the engine, then read the dwell again. Readjust as necessary.
    6.  

    1979 RX-7

    See Figures 3 and 4

    The method of dwell angle adjustment described here requires that some of the high tension wiring be re-routed to permit the engine to run with the distributor cap and rotor off. While this re-routing process requires some extra time, the dwell adjustment may be made with the engine running, which will save considerable time and make it possible for the dwell to be brought to specification on the first adjustment.

    1. Start and run the engine until hot, then turn the engine OFF .
    2.  
    3. Note their locations, then disconnect the high tension leads at the leading and trailing ignition coils.
    4.  



    Click image to see an enlarged view

    Fig. Fig. 3: Temporarily re-route the high tension (secondary) wiring to adjust dwell with the engine running-1979 RX-7



    Click image to see an enlarged view

    Fig. Fig. 4: Adjust dwell by slightly loosening the set screw and moving the stationary contact

    1. Note its location in the distributor cap, then disconnect the leading spark plug wire for the front rotor (L1) at the cap. Connect it to the tower of the leading ignition coil.
    2.  
    3. Note its location in the distributor cap, then disconnect the leading spark plug wire for the rear rotor (L2) at the cap. Connect it to the tower of the trailing ignition coil.
    4.  
    5. Remove the distributor cap and rotor.
    6.  
    7. The plug wires for the top two plugs may still be connected to the distributor cap, but the bottom two plugs must be wired directly to the ignition coils as shown.
    8.  
    9. Connect the dwell angle tester to the trailing ignition coil. Then, start the engine and read the dwell. If incorrect, loosen the set screw for the trailing contact set only slightly (or the engine will stop). Then, very gradually move the stationary contact back and forth until dwell is within the specified range (55-61 degrees).
    10.  
    11. When dwell is correct, tighten the set screw and recheck dwell. Readjust it as necessary.
    12.  
    13. Connect the dwell meter to the leading ignition coil and repeat steps 7 and 8 for the leading contact set.
    14.  
    15. Reconnect all wiring, then reinstall the cap and rotor.
    16.  

     
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