Porsche 928 Workshop Manual page 556

928
Ignition System
28
If specified values are not reached, make
same tests on temperature sensor itself
and, if necessary, replace temperature sensor
Note:
Breaks and short circuits will reduce the
ignition timing by 3" on crankshaft. Intake
air temperature greater than 50 "C/122 "F,
closed full load contact and intake vacuum
greater than 650 mbar will also reduce the
ignition timing by 3" on crankshaft.
TEST POINT 6
Temperature Sensor II
(Engine Temperature)
1. Check plug connection on temperature
sensor I I for tight fit and clean contacts.
2. Connect ohmmeter between terminals 23
and 12 of disconnected electronic
ignition control unit plug.
Specifications:
0 "Cl 32 "F = 4.4 to 6.6 kn
15 to 30 "C/59 to 86 OF = 1.4 to 3.6 kn
40 "Cl 104 OF = 0.9 to 1.3 kn
60 "Cl 140nF=480t0720n
80 "Cl 176"F=250to390n
If specified values are not reached, make
same tests on temperature sensor itself.
Note:
Two independent temperature sensors are
located in the temperature sensor housing.
Connect tester on only one contact of
sensor and a second test lead on ground.
1 - Electronic ignition
2 - LH fuel injection
Temperature sensor I I advances ignition
timing for better engine pickup in partial
load range with a cold engine.
Printed in Germany VI I I, 1984
Troubleshooting Electronic Ignition System 28 - 59