Porsche 928 Workshop Manual page 387

24
LH-Jetronic
928
TEST POINT 7
Auxiliary Air Regulator
1. The auxiliary air regulator will be closed in
heated state.
Squeeze air hose tight -engine speed may
only drop slightly.
2. Pull off plug on auxiliary air regulator and
measure voltage between both terminals.
Specification: battery voltage.
TEST POINT 9
Leaks in Intake System
1. Remove air intake hoses.
2. Take off upper air cleaner housing and
remove hose on blow-off switching valve.
3. Unscrew unlosable hexagon head screws
(13 mm wrench size) in lower air cleaner
housing and remove lower housing with
heated wire air flow sensor. Pull off both
multiple pin plugs.
3. Measure resistance on auxiliary air
regulator.
Specification: 10 45 ohms,
TEST POINT
a
CO and Idle Speed Adjust
ment
See page 24 122.
4. Unscrew heated wire air flow sensor on
lower air cleaner housing and plug air inlet
opening, e. g. with dust cap of original
spare part package and heated wire air
flow sensor.
24 - 118 Troubleshooting LH-Jetronic
Printed in Germany