Reserve fuel problem

[andrewwynn]

There is a design flaw in the siphon jet, did you already address the o-ring defect? If you have the symptom of the right side dropping to zero when the left side still has say 17-20L that's typical symptom for leaking o-ring on the siphon jet. The system doesn't need to be replaced usually just the faulty o-ring

[talljames]

It is a brand new o-ring with the sender unit. A previous thought just occurred to me. I never bent the floater wire a bit as described in another thread. I am now wondering if the floater is getting stuck. So it is showing more fluel in the left when really I am running out!

[talljames]

Alas, I wouldn’t be showing zero in the right though would I if the left float was getting stuck. As you said it shouldn’t go below 1.4L.

[daveking]

Hi
Just taken the left sender unit out and it has been done.

I moved the float by hand but the gauge did not move from a quarter.
With the pipe off and ignition on fuel pumped out of the pipe.

I am stumped.

Thank you.

Dave king

[andrewwynn]

Originally Posted by talljames

Alas, I wouldn’t be showing zero in the right though would I if the left float was getting stuck. As you said it shouldn’t go below 1.4L.

You have it backwards. If the float or the wiper gets stuck reading high that's when the right side will go below 1.4.

Only two reasons the right side will go to zero:

1) there is actually no fuel in the left side and siphon jet is working

2) siphon jet is not working (usually due to o-ring failure)

1a) you may have a reading of yes fuel on the left but not actually have any fuel due to the sending unit not reading correctly

Symptoms of that occurring:

1) fill the tank and reads 3/4 tank
2) near empty tank the distance to empty doesn't change
3) the buffered and non buffered tank total with test six are quite different.
4) reset with test 21 and the fuel amount changed drastically


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[andrewwynn]

Originally Posted by daveking

Hi

Just taken the left sender unit out and it has been done.



I moved the float by hand but the gauge did not move from a quarter.

With the pipe off and ignition on fuel pumped out of the pipe.



I am stumped.



Thank you.



Dave king

You need to measure the Ω on the sender unit as you change the wiper.

The car uses a buffered signal for the gauge so the needle doesn't bounce around like a lawn mower gauge.

If your needle is stuck at a quarter and there is no gas then your wiper needs attention I wrote a DIY repair for that.

If you have gas on the left but none on the right the siphon jet isn't working usually from the faulty designed o-ring seal.

[talljames]

thinking about the bending wire comment. That would probably throw off an accurate reading of fuel left in the left tank. I assume the existing bend is set to a particular value at the factory. I am ruling out this as this is the 3rd sending unit. The original was replaced be ause I thought that was the issue (before I read about it). The replacement was off ebay. Same issue. I decided to get a genuine one and replace that. Same issue. Will post again when I have the fuel system fixed and the answer.