Fuel gauge issue again

ExMX5owner

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Now instead of reading no better than quarter tank no matter how much fuel it had in it.. Now it appears Ill never run out of fuel, its stuck on full, here we go again. Likely causes gentlemen ?...
 

NZ00Z3

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With it stuck on full, it sounds like a sender problem. The gauge is getting a clear signal level, it's just that the level is wrong.

Remove the sender and inspect to see that when you change he sender that the gauge is moving.

@Southernboy or @Pingu wrote a couple of very good "how to's" for the fuel gauge problems.
 
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ExMX5owner

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Queensland, Australia
Model of Z
99 2.0
With it stuck on full, it sounds like a sender problem. The gauge is getting a clear signal level, it's just that the level is wrong.

Remove the sender and inspect to see that when you change he sender that the gauge is moving.

@Southernboy or @Pingu wrote a couple of very good "how to's" for the fuel gauge problems.
Damn I thought so, was wishful thinking to even hope I did not have to pull it out again... Silly as that may seem... I'm still a bit confused as to how the sender works, high impedance on empty or full ?. What should the resistance be at either end, can I test it with a multi meter ?. whereby eliminating any short or break ?, between the sender and the dash. I,m still recovering from the groin injury from pulling a seat out last time...:oops:
 

Mike Fishwick

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BMW have the answer, in the fitting of a new sensor with a gold-plated resistance track. My answer is to fill the tank with 97 octane fuel, as UK 95 is a pretty filthy brew. here in France really good 98 octane is available everywhere, so we do not have this problem. I find that 98 costs about 3% more, and gives about 10% better fuel economy - so long a I do not use Shell V-Power or the BP equivalent.
 

Southernboy

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If you read my write up.. it's a fairly easy task to rectify the problem.
Don't waste your time with resistances etc etc.. The problem is the float catching on the inside of the tank.
 

Mike Fishwick

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With all the potholes on UK roads, it should be easy to shake up the float . . .
 
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