L322 Fuel gauge

OK my 2010 Range rover L322 with the 3.6 TDV8 engine my fuel gauge used to work ok but last week when I filled it up the reading was less than half a tank with a range till empty of 170 miles. This lasted for about 10 days and then one day it started reading correctly i.e. 3/4 of a tank and range of 325 miles, but this lasted about 3 days and then it went back to the low readings as per the first part, and so I filled it up but still it would not go above half a tank. I suspect an intermittent fault but where should I start looking?
Any help much appreciated .

Have you grounded the car onto anything or anyone
A dented tank and sticking fuel sender arm?

There are 2 level senders in tank if 1 is intermittent a full tank would show 1/2 full.

from manual.


“FUEL LEVEL SENSORS
The fuel level sensors are a MAgnetic Passive Position Sensor (MAPPS) which provides a variable resistance to ground for the output from the fuel gage. The sensor is sealed from the fuel preventing contamination of the contacts, increasing reliability. Both fuel level sensors are connected to the external electrical connector on the flange via the connectors on the underside of the fuel pump module flange.
The LH and RH sensors are attached to the fuel pump module and the remote jet pump assembly respectively and are accessible via the fuel pump flange apertures.
The sensor comprises a series of 51 film resistors mounted in an arc on a ceramic surface. The resistors are wired in series with individual contacts. A soft magnetic foil with 51 flexible contacts is mounted a small distance above the film resistors. A magnet, located below the ceramic surface, is attached to the sender unit float arm. As the float arm moves, the magnet follows the same arc as the film resistors. The magnet pulls the flexible contacts onto the opposite film resistor contacts
forming an electrical circuit.

The film resistors are arranged in a linear arc with resistance ranging from 51.2 to 992.2 Ohms. The electrical output signal is output dependent on the amount of fuel in the tank and the position of the float arm. The measured resistance is processed by the instrument cluster to implement an anti-slosh function. This monitors the signal and updates the fuel gage pointer position at regular intervals, preventing constant pointer movement caused by fuel movement in the tank due to cornering or braking.”


Also if you mess with them there is a gremlin where if you do something wrong you end up with it only ever reading half. Can’t remember what that is right now. Do a search it’s been talked about before.

J

Thanks for your replies I expect I will need to replace the pump and sender unit costs around £500 I expect.

nokiakid said:

Thanks for your replies I expect I will need to replace the pump and sender unit costs around £500 I expect.

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Loads on the Bay certainly not £500, think your thinking of the injection pump not the in tank pump.

nokiakid said:

Thanks for your replies I expect I will need to replace the pump and sender unit costs around £500 I expect.

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There are 2 sender units and I think can be purchased separately from the pump.

Find out which 1 is no good/intermittent.

Nothing for L322 is cheap unless it’s crap, but when you look around it can be found at a reasonable cost.

J

Thanks again for replies and not seen anywhere that sells just the sender units they come complete with the pump there is one on ebay fir £319 item number 224354857869 seems like the cheapest I have seen