Porsche 928 Workshop Manual page 416

l
928
Electronic Fuel Injection - LH-Jetronic
24
TESTING OXYGEN SENSOR OPERATION,
'87 MODELS ONWARD
Testing sensor voltage
Precondition:
- Engine at operating temperature.
l.Connect exhaust tester to an
extraction point in engine
compartment.
2.Disconnect oxygen sensor plug.
3.Connect voltmeter to terminal 1
(sensor half of plug) and ground.
4.The voltage must be in 0.1 V to
1.0 V range (depending on concen-
tration of oxygen in exhaust)
Voltage characteristic of oxygen
sensor for working temperature of
600°C.
:_i
I,00 110 1.:
II
Rich mixture Lean mixture
(air deficiency) (excessive air)
5.Oisconnect vacuum line from fuel
pressure regulator. The voltage
signal must increase.
Printed in Germany - XVI,1987
Testing Oxygen Sensor Operation
24 - 219