Ignition Trouble Biggest Problem

Waimarino Bulletin, Volume 5, Issue 2, 9 June 1987, Page 6 (Supplement)

Ignition Trouble Biggest Problem

SOME wintertime trips at the end of a tow rope to a service station or garage can be self-induced. If a car won't start on a chilly morning, although the battery is obviously healthy enough, don't flatten it with endless starting attempts. You've got ignition trouble of some description, or the petrol is not getting to the engine, probably because the tank is empty, although there are other reasons. It is a fact that ignition troubles cause more engine failures - both sudden and cumulative - than anything else. If an engine has been difficult to start for a prolonged period, particularly in cold or damp weather, and if bump starting overcomes the problem, it is likely that the ignition system needs pepping up. With a bump start, the ignition gets a full charge from the battery instead of what's left over after the starter has done its bit. For the most part, ignition faults are of two types. F.ither a spark is not produced at all or the spark is lost or sidetracked either on its way to the spark plug or at the plug itself. Like the common cold, the lost or sidetracked spark is more common in winter when dampness can provide a path of less resistance than a highly pressurised combustion chamber. However, first it must be determined whether the

spark is going to earth somewhere down the line from the cylinder head and that can be done very simply. Disconnect a plug lead and using a pair of pliers with insulated grips, or use a rubber glove, hold the lead about a centimetre clear of clean engine metalwork. Then have someone start the car. If the spark produced between the lead and the metalwork is a healthy bluish white and it is accompanied by a sharp crackling sound, the ignition is healthy. On the other hand, if the spark is yellowish and accompanied by a weak crackle, the ignition is sick. In either case it makes sense to enlist the help of an

automotive electrician who has the diagnostic equipment to pinpoint the trouble spot and make the necessary repair in a fraction of the time that even the most enthusiastic backyard amateur would spend. It may be that there's no spark. Then it is obvious that the ignition system requires a thorough check encompassing the contact points, condenser, coil, connecting leads and distributor, including rotor and cap. If, however, there's a lively bluish white spark, it's probably a fault that has developed because of poor housekeeping. The plugs may need a thorough cleaning and the gaps should be re-set.

That's the sort of job anyone can do, but spark plugs don't like rough treatment, so be careful when taking them out and re-fitting them. Also, remember that they really don't have to be screwed in too tight. If you've satisfied yourself that the plug leads and plug points are satisfactory, it may be assumed that your starting problem relates to fuel rather than electricity. In that case, seek the help of a mechanic rather than an automotive electrician. But before you call him out, have another look to make sure that the petrol tank is not empty!