Important Car Information - Porsche 928 Workshop Manual

28
Ignition System
928
IMPORTANT CAR INFORMATION
Conformance with following safety measures
is necessary to avoid damage on the electronic
ignition system.
1. Never start engine without a firmly
connected battery.
2. Mixing up power supply connections, e.g.
wrong connection of battery, could lead to
destruction of the control units.
3. Never disconnect battery while engine is
running.
4. Never use a boost battery charger to start
the engine. Only use a second 12 V battery
for outside starting help.
5. Disconnect battery from car network
before boost charging.
6. Only measure resistance values after
turning off ignition or disconnecting
battery.
7. Pull off both control unit plugs or make
a firm connection between ignition coil
term. 4 and ground with a piece of wire
before checking the compression (dangerous
high voltage, insulation damage on ignition
coil, high voltage distributor, ignition
cables, etc.). Piece of wire must be inter-
ference suppressed with a shielding sleeve
of at least 2 k-ohms.
8. Never replace specified ignition coil with
a different ignition coil.
9. Never connect a shielded capacitor on
ignition coil terminals 1 and 15.
10. Ignition coil terminal 1 must not be used
for ground connection when installing
a burglar alarm system (ignition coil
would be destroyed with the "ignition
on").
11. Never connect battery positive (+) or
a test lamp on ignition coil terminal 1.
12. Never disconnect ignition lead between
ignition coil terminal 4 and high voltage
distributor terminal 4 while engine is
running.
13. To avoid destruction of the ignition
control unit, secondary side of ignition
system must be shielded with at least
4 k-ohms, whereby the original distri-
butor rotor with a 1 k-ohm shielded
resistor must be installed (do not use a
5 k-ohm distributor rotor even for radio
and communication equipment
suppression).
a
28 44
Important Car Information Printed in Germany