Page 121 - Vauxhall 20-60 H.P. (R Type) Chassis Shop Manual

VAUXHALL 20-60 SHOP MANUAL

or 12 volt type coil, which was introduced on chassis number R 3882, and as
this is the only type of coil serviced, it is necessary to remove the resistance
unit from the ignition circuit when fitting this latest type coil to any car
bearing chassis number prior to R 3882.

TRACING AND CORRECTING

IGNITION DEFECTS

SECTION If the engine will not fire, switch on the lamps or operate the starter. If the
536 battery is in order, the lamps will light properly and the starter will turn the
engine.

( Even if the battery is almost totally discharged, as long as it is capable of
making the lamps glow, it will supply sufficient current for ignition purposes.
Under such circumstances it will of course be necessary to crank the engine
by hand. ) It is advisable to investigate the cause of the discharged battery
and see that the fault is rectified immediately.

Low Tension Wiring: — This is by far the most frequent source of trouble
and should be examined for loose connections and breakages. It is a very
common mistake to blame the coil when the real trouble lies in a faulty
connection.

Ignition Switch: — Make sure that this is making good contact. The
ammeter should show a discharge when the ignition is switched on, unless
both contact points are open. In this case the ammeter will show a discharge
as soon as the engine is turned over by hand.

.
Resistance Unit ( Before R 3882 )
( a ) See that the coil wire is not broken.

( b ) See that the unit is not loose, and that the coils do not touch one
another.

This unit is not adjustable in any way; if defective, it should be replaced.

Contact Points: —Remove distributor cap and examine the contact points.
If badly pitted they should be cleaned and adjusted ( Sections 526 and 527 ).

Coil: — If on attention to these points, it is still impossible to start the
engine, remove the high tension terminal from the distributor and hold
it about a quarter of an inch away from some part of the engine. Switch
on the ignition and turn the engine over by hand. The sparking should be
strong and regular. Take care that the fingers are not less than 3’ from end
of the high tension lead when making this test.

If a weak spark is obtained remove the low tension lead between distributor
and coil and connect a 12 volt lamp between the coil terminal ‘T’ and earth
when the lamp should light. If it does not transfer the wire from the bulb
from terminal ‘T’ to the coil terminal ‘B’ ( See wiring diagram, Fig. 18 ).

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