Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Fuel gauge sender/rack

Sounds slightly odd as the number is a percentage not a distance. Modern cars can give you a range left (in miles) based on current consumption and an estimate of fuel left - but not as a %!! - what is it a % of ?! The estimate is expressed in miles. Just reset the trip and do about 180 miles and fill - plenty of margin

I think the mechanic was making an excuse for the very inaccurate fuel indication that fluctuates as the fuel sloshes around the two tanks when you corner. You will have more than half a tank of fuel left when it starts to show 0% if it has the original tank sender still. As I am sure you are aware there is a 280mm version that improves the accuracy a little. Nice looking Brooklands.

I installed the 280mm at new and it's become just as inaccurate as the original now. Reads 0% after about 120-130 miles. That's about 1/2 tank.

Well then, that is money I wont bother spending then!

And my email to support at VDO is still unanswered.

Think I might smell some BS here.

Hi Ken
I faced as well some issues with the indicated fuel level no matter if we are talking about the original 250mm or the longer 280mm version.
I get a better idea what might be the reason for that issue I measured the resistance in Ohm directly at the fuel sender. The VDO tubular senders will report 90 Ohm when the float is at the lowest position. At the highest they show around 0 Ohm.
After having driven 205 miles the value was at 75 Ohm and I was able to refill 6,6 us gallons. The instrument reported 18% fuel level (just ignition on, but engine not running). After starting the engine the fuel level dropped to zero.
I was't able to figure out why the fuel level is always dropping after starting the engine, but I watched this effect frequently. I forgot to measure the Ohm value with running engine, to see if it will drip down as well.
Normal VDO fuel gauges can be adjusted to the zero Ohm value, but it is not clear, if this is the case for our instruments as well.

Hears a thought - maybe the shaking chassis at engine idle froths up the fuel

So today with only 25 miles on the trip odometer, the fuel gauge is at 98%. I leave the local cats and coffee and hit the highway. The gauge stayers dropping big by about 2% a click every second until it was down to 60%. I wondered if I had a leak! Then it began going back up by 2% until in got back up to about 80%. Is this electrical or mechanical? My impulse is to remove the sender to see if it's fuel logged, make sure connections are clean and tight, etc. but it seems everybody has had their 280mm senders go from reliable to haywire with time.

Ken, My 280 is still operating ok and you know that I changed mine right after you did.

Dolph