Thread: fuel gauge missreading

Originally Posted by bob h

Hi all, been a while but I am now the owner of a good Disco 1 93 model 3.5l. My problem is that I filled up the fuel for the first time after I got the veh on Sunday with E10 and after doing approx 250kms, the fuel gauge wont read above empty or 1/4 tank and the fuel light comes on and stays on. When I picked up the car, it had 1/4 tank of fuel in it and the fuel light wasnt on. also, the gauge moves around a lot as you go around corners. Is there an easy fix to get the gauge working right again? Thanks . Bob

The fuel pump/sender assembly is accessible under the load area floor via a hatch under the carpet. The plastic float may be stuffed, or unable to cope with E10. It should be easy enough to remove the float and replace it with another. Disconnect the pump plug while idling to depressurise the fuel lines before you dismantle.

Thanks Bee Utey, Im hoping that the E10 hasnt done anything bad. Just put 15ltrs in to the fuel tank [normal unleaded] and the gauge is back to reading right now [1/2 tank] and the fuel light is off.

While you have the sender out of the tank, physically move the float arm up and down and check that it's registering on the gauge. I haven't seen the Disco sender firsthand, but many of the senders I have seen which have a "Low Fuel" light, actually have two resistance coils, be they wire or a carbon track. The first track does the last quarter of tank, and turns on the low fuel light, the second track does the rest of the tank with no low fuel light. There may be a short somewhere in the sender.

Originally Posted by mike_ie

While you have the sender out of the tank, physically move the float arm up and down and check that it's registering on the gauge. I haven't seen the Disco sender firsthand, but many of the senders I have seen which have a "Low Fuel" light, actually have two resistance coils, be they wire or a carbon track. The first track does the last quarter of tank, and turns on the low fuel light, the second track does the rest of the tank with no low fuel light. There may be a short somewhere in the sender.

Thanks Mike, I was going to move the float and check the gauge. I did not realize that there were two resistance coils. I suppose that if I disconnect the first track then I would not have a low fuel light warning. Correct or not? Thanks, Bob

Originally Posted by bob h

Thanks Mike, I was going to move the float and check the gauge. I did not realize that there were two resistance coils. I suppose that if I disconnect the first track then I would not have a low fuel light warning. Correct or not? Thanks, Bob

Assuming that it's the type of sender that works off two coils, then yes. AS I said, I'm not familiar with the Disco sender, but senders I have pulled apart in the past with a low fuel light output, worked on this principle.

I only posted it as something to check, more than likely I'm overcomplicating things, and it's simply a buggered float or sender