Download Print this page

Porsche 912E Technical Manual page 13

L-jetronic fuel injection system
Hide thumbs Also See for 912E:

Advertisement

Fuel Injection
Valves
Fuel Pressure
Air Flow
Sensor
Temperature
Sensor II
Note (1): Activated charcoal filter hose must be disconnected at air cleaner, the
air injection hose must be removed and the check valve must be plugged. The
adjustments should be made as quickly as possible to prevent excessive heat in
intake lines.
ACCELERATION NOT SMOOTH
Possible Problem
Throttle Valve
Switch
Air Intake
System
Auxiliary Air Device
Air Flow Sensor
Exhaust Gas Mixture
1. Verify the operation of each injection
valve by disconnecting the electrical
supply to each injection valve, one at a
time and determine if the engine speed
drops when the valve is disconnected.
2. If the speed drops, the valve is
defective.
3. Measure the resistance of the coil of
each injection valve. Should be 2-3
ohms.
Verify the fuel pressure is correct.
Verify the air flow sensor is functioning
properly.
1. Measure the output of the
temperature sender unit under various
conditions. Following values should be
used for reference purposes, but the
value may be different due to the age
of the sensor.
Temperature Range
0
68
F
0
14
F
0
176
F
Procedure
1. Verify function of throttle valve.
1. The air intake system must be free
of leaks. Check the intake manifold,
hoses and associate components with
soapy water to determine if leaks are
occurring.
1. Verify function of auxiliary air device.
1. Verify function of air flow sensor.
1. If the concentration is too high,
adjust the bypass screw in the air flow
sensor ½ turn counterclockwise and
measure again.
Value
2k – 3k ohms
7.5k – 12k ohms
250 – 400 ohms
13

Advertisement

loading