Technical Fuel gauge DEAD - ideas..??

[varesecrazy]

Hi,


the gauge was working fine last season,
assumed fuel had evaporated, put in a gallon, stil reads empty..

have given the gauge a light tap..
any other diagnostic aids before pulling things apart.?


:idea:
I've stored planks under the car..
is the sender / its wiring really exposed.. easily knocked..??


cheers,
Charlie

 

[purf]

Mouse eaten you sender wire ontop of fuel tank??? ?

They like to nest here in my experience. Access to check from under rear seats.

Oh Hang on. This isn't the cinquecento forum ? haha. Well I guess it could still happen in an x19.

It's a bit early for me sorry

On the x the wires all come out the top of the engine bay through that big rubber cover which turns into dust when you touch it ?

 

[purf]

Any luck?

 

[X19 pilot]

Mine goes dead when half full, above this level and it works fine. I have been told it is caused by a break in the wire of the sender/float, which, when the float is high, there is enough of a connection to close the circuit. When the tank reaches the half way point, the gauge bounces around for a few miles when going through corners, then reads empty.

Does yours work when full?

Its a great game of roulette when you are travelling through rural France and there not a petrol station for miles around...

I don't know if it is an easy fix or not.

 

[varesecrazy]

Any luck?

went for it's 1st proper drive.. gauge still essentially dead,

after 10 miles, attempted to fill the tank at a fuel station.. clicked almost immediately.. got 3 litres in ..

I seem to recall I "filled it" before the winter..

:idea: maybe the float has failed and sunk.. not got underneath properly to investigate.. but certainly nothing odd hanging down..


have noticed one of the ancient tyres is badly perished.. might get a brand new
"stock" Cinq pair put on ..as I'll never use them otherwise..

lower profile.. but should be fine as an axle pair

 

[purf]

I had 165 55 13s fitted and they looked a bit small. Would work at the front. I can find a photo later

 

[varesecrazy]

I had 165 55 13s fitted and they looked a bit small. Would work at the front. I can find a photo later

that was my plan..
mainly as it's @£100 of rubber just sitting there.. slowly degrading..

 

[purf]

165 55 13 Cinq tyres with -30mm apex springs on the front end. The rear is on the standard 1500 springs. Hence big arch gap!

 

[varesecrazy]

Put a sei sporting alloy on the front

175/50/13... looks daft..is the same rolling dia. As the cinq tyres...

So will put a pair of 165/70/13 on the X

And the new pirellis can go on the sei..good to know rolling dias are the same

Thanks for the help...need the drive to Brooklands to be as drama free as possible..

Charlie

 

[purf]

I got 4 part worn 165 55 13s fitted for under £90 yesterday. The Cento size are getting less common though.

 

[F123C]

Hi Charlie,

You probably know this already!!

Iirc the easiest way to check out a faulty fuel gauge is to earth each of the two wires going to the sender unit on the fuel tank. One wire when earthed will cause the low fuel warning light to come on, earthing the other wire should cause the fuel gauge to read full. This test rules out a problem with the gauge and the live supply to the gauge, fuse etc.

If you can remove the tank sender unit, you can often figure out what has gone wrong and maybe fix it. The sender unit mounting plate (with the 6 little 7mm? nuts ) has to be earthed itself by some means/route.

I remember one car (possibly a 131?) with a gauge reading zero - the plastic float had popped out of the float arm. Never found out how it had happened, was on an almost new car.

Al.

 

[varesecrazy]

UPDATE,
got 2 x good replacement tyres.

headed out to Brooklands, over bumps the "big amber low fuel light" was flashing..,:chin:
then became ALMOST constant.., so stopped and added @£25 ,

the Gauge then showed @1/2 full, and kept reading a sensible figure over another 3 hours of running.

other news.. car cut out in a huge queue.. " vapour lock"..??

restarted instantly once cold and drove the 60 miles home without incident..

 

[purf]

Yeah they all get that vapour lock when hot . One solution is wrap the fuel lines with insulation.

If possible fit a heat shield to the exhaust manifold. Most x1/9s don't have the original heat shield fitted.

The old fuel sender on my x used to make the gauge jump iratticaly when less than half full. It would read correct at the top of its 'jumps'. I fiddled about but never sorted it until i fitted a replacement sender. It must have been the coil worn out but it didn't look it.