Faulty fuel sender?

[NARCEA]

Hi guys.

AUII Forte.

Switch her on fuel guage shows full. 10 seconds later, drops straight to empty. DTE displays 479, and no fuel warning beeps or light.

Any ideas besides a faulty fuel sender, only other one I can think of is float not free to move as it is been in a prang, however fuel tank not damaged.

Could it just be low on fuel.... and DTE a result of battery being disconnected??

Any pointers shout out, otherwise I'll probably fiddle tomorrow and Monday.

Cheers,

ian

[AUXRVIII]

This fault is usually related to a higher than normal resistance in the fuel sender which means it will have to be replaced or an open circuit in the wiring. Check the connecter at the tank for corrosion or backed out terminals. Sedans weren't common for having sulfur affected senders.

[AWD Chaser]

mmm, I would say prob, a short somewhere as a dead sender unit wouldn't first say full. Check your wiring for the sender and also check your fuses too - can't hurt.

[AUXRVIII]

Originally Posted by au3 chaser

mmm, I would say prob, a short somewhere as a dead sender unit wouldn't first say full. Check your wiring for the sender and also check your fuses too - can't hurt.

The cluster guage goes to full then to empty when there is a high resistance, this can be caused by sulfur build up of the sender, very common on AU/BA wagon & ute & also LR Focus. The fault can be reproduced by using a resistor wheel, when too much resistance is dialled up the guage will go to full then back to empty.

[EA_Bender]

This happened in my EA, fuel guage rose to full then dropped straight back to empty, replaced the sender unit and it was all good, there was no corrosion on it, it was just old and it wasnt touching the contacts properly any more.

bender

[NARCEA]

thanks for the input guys i'll let you know what it turns out to be when i start to fiddle.

ian

[V8falcons]

My au2 wagon SR does the same thing when I fill it up after about 50ks it goes back to full.

[NARCEA]

Can someone tell me what fuses to check for what I've described above? I didn't get the handbook with the car, save me pulling them all out. I'm getting stumped with this problem. The car seems to be able to tell when the sender is not plugged in because it will crank but not start. Anyone also able to help me with a wiring diagram for it so I can have some fun and work backwards.

Cheers,
ian

[AUXRVIII]

Originally Posted by NARCEA

Can someone tell me what fuses to check for what I've described above? I didn't get the handbook with the car, save me pulling them all out. I'm getting stumped with this problem. The car seems to be able to tell when the sender is not plugged in because it will crank but not start. Anyone also able to help me with a wiring diagram for it so I can have some fun and work backwards.

Cheers,
ian

If your disconnecting the sender at the tank you will also be disconnecting the fuel pump, this is why it won't start.

[NARCEA]

well that makes sense.... haha
can you shed any light on which fuse I should be looking for?

[AUXRVIII]

Originally Posted by NARCEA

well that makes sense.... haha
can you shed any light on which fuse I should be looking for?

Forget about the fuses, refer back to my first post.

[NARCEA]

the male and female connector and plug are spotless, i've dabbed both with some crc but to no avail.

[AUXRVIII]

It was common for the senders to have a layer of sulphur build up on the sender contacts, thats why I mentioned it may have to be replaced, if no faults are found with the wiring.

[NARCEA]

yah i'm going to try fuses, then sender (donor taxi may help with this), then as a last resort wiring. cheers for your help.
ian

[NARCEA]

SOLUTION (finally got around to having it looked at): completely f ked fuel sender unit. It had twisted and wrapped around itself, and was making a poor contact.

COST TO FIX: 215 bucks at autoelectrician

cheers,
ian

[EA_Bender]

Good to hear you got it fixed mate