Fuel Consumption Sensor, Checking & Adjusting
Fuel Consumption Sensor, Checking:
Fuel consumption sensor, checking
- remove connector on fuel consumption sender (arrow)
Connector:
- connect voltmeter between contacts 1 and ground cable
- switch ignition ON
^ specified value: approx 5.0 V
If specified value is not attained, - repair break in wiring using current flow diagram
Connector:
- connect voltmeter between contacts 1 and 3
^ specified value: approx 5.0 V
If specified value is not attained, - repair break in wiring using current flow diagram
Connector:
- switch ignition OFF
- connect ohmmeter between contact 2 of fuel consumption sensor connector and contact 8 of 25 point computer control unit connector
^ specified value: 0.0 ohm
If specified voltages are not attained, - repair break in wiring using current flow diagram
VAG 1501:
- connect VAG 1501 between fuel consumption sensor and sensor connector
- remove air intake duct from fuel distributor
- connect voltmeter to VAG 1501 between terminals 2 and 3
- air flow sensor at rest position
- switch ignition ON
^ specified value: approx 0.0 V
If specified value is not attained, - replace fuel consumption sensor
Attach Adjusting Tool (VW 1348/1):
If specified value is attained,
- attach adjusting tool (VW 1348/1)
Note
Before mounting tool, set slide (2) at extreme upper position. Attach adjusting tool centrally on the rim of air flow sensor. Pointer (3) must face toward fuel distributor.
- push in slide (2) as far as it will go
- turn in adjuster screw (1) until magnetic tip contacts mounting screw of sensor plate (sensor plate in rest position)
- pull up slide (2) of adjusting tool to first stop (idle position)
^ specified value: 0.2-0.5 V
- pull up slide (2) of adjusting tool to second stop (full throttle position)
^ specified value: 4.0-4.5 V
If specified values are not attained, - replace fuel consumption sensor
- measure duty cycle with VAG 1362 or Siemens 451
- connect tester between contacts 19 and 12 of computer control unit connector
- start engine
- measure duty cycle
^ specified value: 25-65%
Computer Control Unit Connector:
Computer control unit connector
If specified value is not attained
- check Llambda sensor
If specified value is attained and fuel consumption display deviates a lot from actual consumption, - replace computer control unit
Fuel Consumption Display Sensor, Removing and Adjusting:
Fuel consumption display sensor, removing and adjusting
- remove air intake duct
Fuel Consumption Display Sensor, Removing and Adjusting:
- remove mixture control unit from air filter housing
Note
Do not remove fuel lines
Fuel Consumption Sensor Connector:
- remove fuel consumption sensor connector
CAUTION
Do not touch sensor contact surface or contact tabs in air distributor
Fuel Consumption Sensor:
- unscrew fuel consumption sensor from air distributor housing (arrows)
- carefully remove sensor
- install new sensor and adjust
VAG 1501:
Fuel consumption sensor, adjusting
- connect VAG 1501 between sensor and connector for consumption sensor
Mixture Control Unit:
- position mixture control unit so sensor plate moves freely
Attach Adjusting Tool (VW 1348/1):
- attach adjusting tool (VW 1348/1)
Note
Before mounting tool, set slide (2) at extreme upper position. Attach adjusting tool centrally on the rim of air flow sensor. Pointer (3) must face toward fuel distributor.
- push in slide (2) as far as it will go
- turn in adjuster screw (1) until magnetic tip contacts mounting screw of sensor plate (sensor plate in rest position)
- pull up slide (2) of adjusting tool to first stop (idle position)
^ specified value: 0.2-0.5 V
Mounting Screws:
If specified values are not attained, - loosen sensor mounting screws (arrows)
- move sensor in slots until specified value is attained
- tighten sensor mounting screws
- repeat test in idle position
If specified value is still not attained, - replace air flow sensor assembly
If specified value is attained, - perform test in full throttle position
Adjusting Tool:
Test In full throttle position
- pull up slide (2) of adjusting tool to second stop (full throttle position)
^ specified value: 4.0-4.5 V
If specified value is not attained, - repeat test in idle position and/or repeat basic adjustment of special tool
If specified value is attained
- push slide (2) all the way down
^ specified value: 0.0 V
If specified value is not attained, - repeat test in idle and full throttle positions
Note
If specified values are not attained after repeated testing and adjustments, - replace air flow sensor assembly
If specified values are attained, - seal mounting screws with paint