Porsche 928 Workshop Manual page 561

28
Ignition System
928
8.3 Oscilloscope must display a control
signal on each of both multiple-pin
plugs.
TEST POINT 10
L
Alternator, Regulator
Peak voltage of the alternator could cause
engine misfiring.
1. Take off flat drive belt on alternator.
2. Start engine.
If misfiring has been eliminated, check
alternator and regulator.
TEST POINT 9
Octane Loop
An additional single-pin plug is located on the
bottom of the multiple-pin plug for the
electronic ignition control unit.
-m
:,- L
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i _
,,i
-1
i;,
4
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IT 7" "
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With this plug connected the ignition timing
will be retarded approx. 3" at full load and
high partial load.
(Provision for adaptation to poor grade
gasoline.)
a
28 64 Troubleshooting Electronic Ignition System
Printed in Germany