strange petrol gauge

[shnozz]

how odd, upon getting back off holiday i climb into my baby and see the petrol gauge is reading empty. cannot think that i would leave the car with no fuel in so strikes me as odd but pop to petrol station to fill up. at about £14 it cuts out - thinking its the usual cutting out problem, i continue to then pour a load of petrol in and then out of the overflow pipes - clearly the tank must have been half full in the first instance. very odd. it gradually appears to be coming back to life (even after filled up it only read half full) - anyone have an idea what would have caused this?

BTW - slightly concerning report from my parents neighbours that whilst on holiday 2 young men had been walking around the car and removing Harry's cover - found the dust sheets i had laid underneath had been removed when i returned. The parents gaff is middle of nowhere too. Arseholes.

[JSG]

Shnozz,

This is not unusual for an S fuel gauge, my S3 did the same sometimes - in the end it stopped working altogether. I gather that the sender unit is prone to playing up - it gets loads of crap off the roads and the gauge itself can get 'sticky' if the car is not used.

Cheers,
JSG

[M@H]

quote:
BTW - slightly concerning report from my parents neighbours that whilst on holiday 2 young men had been walking around the car and removing Harry's cover - found the dust sheets i had laid underneath had been removed when i returned. The parents gaff is middle of nowhere too. Arseholes.

...good of the neighbours to have a friendly word with them... this could so easliy have read:

"concerning report from my parents neighbours that whilst on holiday 2 young men had been up to the car with tools, opened it up, and drove it away.."

Matt.

[johno]

Schnozz,

The petrol gauge in the tank is a rather basic effort with swing arm and resistor block. If this resisance is stuck for some reason this will give you crud readings.

It will come back to life with use though as you have found.

Cheers

Mark

[lavingp]

Just had a similar problem on my S3. The internal resistor block is earthed through the metal disc. This in turn relies on a good contact to the tank itself. The answer is to remove the sender and clean up the metalwork so there is a good earth return path from the resistor to the body of the tank. Check the connections on the supply side as well whilst you're under there. If you earth the metal disc with the sender removed (and power on etc) you can watch the needle on the gauge move as you move the float up and down. This should prove everything else is working OK.

Having said all that, my tank still reads empty when half full, so I must take another look at it.

[HarryW]

quote:
BTW - slightly concerning report from my parents neighbours that whilst on holiday 2 young men had been walking around the car and removing Harry's cover - found the dust sheets i had laid underneath had been removed when i returned. The parents gaff is middle of nowhere too. Arseholes.

Are you sure they didn't steal, your tank sender or they didn't just need the sheets to keep warm, bl**dy travellers

I hope the cover without the dust sheets didn't rub the paint too much, nothing a good polish can't sort out anyway.
I hope you had a nice time on the Hols, you missed some loverly weather whilst away, at least 30 deg, NOT.
Hope to see you for a for a blat v soon,

Harry

[Dave_H]

Shnozz,

Johno and LavingP are right, the sender unit is a bit iffy, I took mine out and cleaned it and it's never played up since.

Before you do that, I'd remove the live wire from the sender and connect it to earth, then turn the ignition on. If the gauge/electrical connections are ok then the gauge will read end stop (beyond full)

You can then wiggle the earth wire to see if this has a bad connection - if it has the gauge reading will drop.

Cheers,

Dave.

[shnozz]

thanks all for your thoughts - much appreciated. it seems to have come to life a little since the weekend so under my "if it aint broke" logic, I am going to stick with it and see how i get on. If its still not right, you have been a great help and will follow that trail.

Harry - hols were great except plane turning around with hydraulic failure and then a 2 day delay before we could get home!! Will meet up soon once sorted out a few niggles see my post re this weekends work!) and have some free time - are u up for the M3 meet? if so, I feel a nice A32/A31 blast coming on.

PS - I now have a £60 a week petrol addiction.

[mikes3]

M3 Meet? When, Where etc, white S3 often between Boringstoke (work) and Gosport (Home sweet home!)

Rgds

Mike

[shnozz]

Hi Mike - have a look on the general TVR forum - hope to see you there