fuel guage

remy · newbie Joined: 23 Jun 2002 Posts: 5

My fuel guage jumps around and doesn't give me a reading. Usually it just sits on empty. I changed the sender with a second hand one but it still didn't work. I brought it back to the wreckers and they gave me a fuel guage instead thinking that might be the problem. I changed that and it still didn't work. Is it most likely that it was the sender and the replacement would have been faulty? Any suggestions greatly appreciated.

Gene FJ20DET · Posted: Sun Jun 23, 2002 10:16 pm Post subject: Re: fuel guage

they all bounce around
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TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

to see wat the prob is go to a auto sparky ask him to check your fuel guage out. i bought a Tf with 95000 on the clock and the sender unit in that was fine and didnt bounce around. Or for $90 u can buy a brand new one

Soop · backyard mechanic Joined: 30 May 2002 Posts: 748

On my 78 TD wagon the fuel guage doesn't bounce at all. Sure it moves a little when you go up and down hills but thats pretty normal for most cars.

However, on my old wagon.. a TF the fuel guage bounced all over the place.

Weird.

kickemharder · rice boy Joined: 12 Jan 2002 Posts: 27

The reason it jumps around is because the sender is basically a variable resistor and it works by the lever that sit in the fuel has a floaty on it and as it rises the other end goes up and down a shaft that has a coil around it. So when the tank is full it sits at the end with the corresponding resistance level. After a while say 18+ years the coil wears down and you get short circuits and you resister starts to have sudden changes in resistance and the needle try’s to reproduce the signal thus a bouncy gauge.
To fix it you need to get the coil re-wound but don't do it yourself because it needs to be done with the right wire and then calibrated so as to give the correct measure.

Ben

alan · tinkerer Joined: 07 Apr 2002 Posts: 429

They dont all bounce around. the early style guages from the TX to TE were stable, and very reliable. When the newer TF/TG dashes came , thats where the troubles started. Yours is a TF/TG right? They do bounce a little but you should still get a reading. If it sits on Empty id say your guage is rooted. they all eventually go on the TF/TGs, whereas the aerlier ones never break down in my experience.

Make sure you are tightening all the screws down when you insert it, it needs to be grounded properly. If no go, then buy a new one. The sender units are usually never the cause of the problem, they are dead reliable.

alan · tinkerer Joined: 07 Apr 2002 Posts: 429

The theory sounds good, but thats not what happens in real life, I ve had many Gems , all models over 20 years old , never had a problem with the sender.

Getafix · tinkerer Joined: 16 Jan 2002 Posts: 146

im thinking its a loose wire.. i just fixed my temp guage (just by sliding the wire back on) and it was jumping around until i fiddled with it and made sure it was on properly.. so try checking connections i guess