VW PASSAT JITTERY TIMING
Q I have a 1974 VW Passat 1300 and have recently carried out my usual annual maintenance. After replacing the contact points, condenser etc, I always check the timing to ensure that this has not been upset by the fitting of the new points. I painted the mark on the flywheel many years ago which makes this a quick job, but this year I noticed that when using the strobe light to check the timing, the mark on the flywheel seems very jittery and is moving back and forth, not staying firmly where it should as I am sure it has always done in the past. Can you explain why this may be happening? Kim Robinson
A The most likely reason for the fluctuation you are seeing when using the strobe light is that the springs on the distributor’s centrifugal weights (bob weights) have become weak, or that the pivot points for the weights have become worn. You can easily test the springs to see if they are performing correctly by removing the distributor cap, then holding and twisting the rotor arm. As you twist the rotor arm you should feel a light resistance, and when you let go, it should go back firmly into its position of rest. If this is not the case, then you may be able to remedy matters by finding and fitting new springs to the centrifugal weights. At the same time it may be advisable to place a light lubricant on the pivot points to free up the mechanism. You should also check the vacuum advance and retard system to ensure that this is connected well and operating as it should.