Porsche 928 Workshop Manual page 383

24
LH-Jetronic
928
6. Checking "Free Burning"
of Heated Wire
6.1 Visually inspect
- plug connection and contacts,
- wire grid for damage and
- heated wire for breaks.
6.2 Install air flow sensor with lower air
cleaner housing.
Coat O-ring in air guide housing with
silicone for this purpose.
Connect plugs on air flow sensor and
temperature sensor.
Push in air flow sensor carefully.
6.3 Do not install filter element and upper
air cleaner housing.
Run engine having operating temperature
at approx. 2,000 rpm and then switch
off ignition.
Observe heated wire with help of a
mirror.
24-114 Troubleshooting LH-Jetronic
Printed in Germany
Heated wire must glow about 1 second
after waiting approx. 4 seconds.
Check activation and wires in case of
malfunction.
(LH plug terminal 8 to air flow sensor
terminal I).
TEST POINT 4
Temperature Sensor I I
(Engine Temperature)
I. Check plug connection on temperature
a
sensor II for tight fit and clean contacts.
2. Connect ohmmeter on terminals 2 and 5
of disconnected LH multiple pin plug.
Specifications:
0 "Cl
32 "F = 4.4 - 6.8 kn
15 to 30 "C/59
to 86 "F = 1.4 - 3.6 k.Q
40 "Cl
104 "F = 0.9 - 1.3 kn
60 "Cl
140 "F = 480 - 720 .Q
80 "Cl
176"F= 250-390R
If specified values are not reached, repeat
same tests on the temperature sensor
direct.