4.2
Dwell-angle measurement
The dwell angle must be measured if the
engine is to be adjusted precisely.
The build-up of the magnetic field in the
ignition coil requires a specific amount of
time, in order to attain maximum ignition
performance. If this time is too short,
misfiring can occur in the upper engine
speed range. The build-up of the magnetic
field begins when the points close or when
the transistorized output stage is shifted
through. It is therefore important that the
time during which the points are closed, the
so-called dwell period, is sufficiently long.
The dwell period depends on the following
factors:
1. The number of cylinders in the engine
2. The engine speed
3. The dwell angle of the ignition distributor
4. The type of ignition system.
The dwell angle is the angular range, within
which the points are closed or the
transistorized output stage is shifted
through.
1 = Opening angle in 4-cylinder engines
2 = Dwell angle in 4-cylinder engines
24
1
2
456041P
4.2.1 Connections
See Section 4.1.1
4.2.2 Setting
Switch the measurement-mode selector
switch to position <.
4.2.3 Reading off
Dwell angle in %.
Compare the nominal and actual values.
(For conversion of the dwell angle from a
percentage into degrees of the distributor
shaft (°<) see table on the front of the unit or
on the rear of the cover)