Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Fuel level gauge

As some have noted, the primary issue is the sender, not the gauge. So coming up with a suitable sending unit that fits the tank flange with the correct depth will be the challenge.

As I recall there are some algorithms performed by the ECU which add another level of disparity to the gauge readout. It's not just a matter of getting a perfect sender therefore.

Morgan designed the system to show zero before the tank is empty so even if working correctly it should show zero after you've used around 30 litres. The 280mm sender has the same problem but simply goes to zero a bit later.

The fuel gauge is an digital system being fed by an analogue sender which is why the gauge never reads for example 99% or 1% but jumps in about 20 or so steps from 100 to 0. The issue is not the sender (which has a linear reading from 0 to 100) but the way the ECU interprets the reading.

Years ago Charles Kirby spent a huge amount of time trying to develop a black box to plug in the sender to ECU loom to improve the accuracy, often driving with a laptop in the system so he could monitor and tweak the algorithm and correct the readings. In the end he gave up as he still couldn't get a consistent reading.

So If you want a more accurate system then you will need a separate (preferably analogue) gauge and, depending on what you choose, another type of sender. You will need to run separate wiring from the sender to the new gauge.

In terms of range the rule of thumb is to look to fill up around 200 - 230 miles (320 - 370 Km) but I've done over 270 miles several times and still had 5 or 6 litres of fuel in the tank. However remember when you're low on fuel it's split between two tanks the actual level of fuel around the fuel pump is only a couple of inches so I don't recommend doing this regularly!

The tank holds 40 litres and reckon on consumption in the low 30's mpg so after a few fill-ups it's pretty easy to work out a "need to fill up" range for your driving.

Around 4 years ago I cleaned the two resistance wires on my (280mm) sender and it has behaved itself ever since, giving reasonably accurate and consistent readings. Therefore, I recommend doing this before doing anything more drastic!

My fuel gauge was worse than useless so purchased the following fuel sender, which is longer than the original, from Demon Tweeks and it works perfectly now

VDO Dip Tube Type Fuel Sender For VDO Gauge Length: 292mm SKU: VDO224-011-020-292G