Operation CHARM: Car repair manuals for everyone.

740/760 1982-1986 -- T14

Fuel lever sensor, adjustment T14
740/760 1982-1986


For 1986 with tubular type sensor, see T16.

Before adjusting, fault tracing should be carried out on fuel gauge and sensor. To correct reading which is too low, a rheostat can be connected in parallel with the sensor as set out below in order to lower resistance.
The following potentiometers should be used for adjustment:
1983: P/N 3 515 294-1
1984-1986: P/N 3 515 716-3.

- Place car on level surface.
- Remove battery negative lead.




4-door:
- Remove draining pipe on left side.
- Remove cover over spare wheel and fold back tank carpet.
- Remove protection cover and shroud on filler pipe.




5-door:
- Remove rear floor panel.
- Fold down seat back.
- Remove three nuts retaining floor panel.
- Remove floor panel by raising and pulling forward.
- Remove cover over left suspension tower.
- Remove lid over tank gauge unit.
- Remove filler tube from gauge unit.

Cars without an auxiliary tank:
- Siphon fuel through filler hole In tank gauge unit with the help of tank drainer.




Cars with 20-liter (5.3 US gal.) auxiliary tank:
- Remove auxiliary tank gauge unit and siphon fuel from tank
- Remove auxiliary tank screws and raise tank so that filler tube becomes accessible
- Remove filler hose and siphon fuel.

Cars without an auxiliary tank:
- Fit filler tube and cover over gauge unit.

Cars with 20-liter (5.3 US gal.) auxiliary tank:
- Fit filler tube, auxiliary tank and gauge unit.
- Unplug tank gauge unit connector.
- Measure resistance between sensor lead and ground. Resistance should be: 250-350 ohm.
If reading is incorrect either the tank is not completely empty or the sensor is faulty and needs changing.




- Fill up with 11 ± 0.5 liters of fuel (2.9 ± 0.13 US gal.)
- Measure sensor resistance as described before.
Resistance should now be: 141-240 ohm.

If incorrect, the sensor must be changed.




- Fit tank gauge unit connector.
- Refit battery negative lead.
- Turn on ignition and wait for approx. 3 minutes. It is not possible to take a correct reading before because of damping within the instrument.
- Pointer on fuel gauge should now be just touching the red area.
If gauge registers above the red area, i.e. Indicating more fuel in tank, it can be adjusted as described.




- Turn on ignition.
- Connect the potentiometer between connectors, as illustrated.
- Connect ground lead to tank gauge unit ground point.
- Set potentiometer to mid position.

- Reassemble in reverse order.