Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Fuel Gauge or Sender Problem?

Hello,

I have a 2009 Plus 4 that has a fuel gauge problem that means I can't ever be sure how much is in the tank unless I drive using the trip. I know the gauges on Morgans are vague but the fuel gauge inaccuracy is something I have to address. The gauge doesn't flicker it just moves randomly by a quarter of a tank at will! I cannot fill the tank up for it to read full and I'm not brave enough to drain it. A few questions:

1. Any thoughts as to whether this is a defective gauge or is it the sender?
2. Is there a sequence, tester or process to go through to identify the exact component that's failed?
3. It's a black faced Smiths gauge with three functions - oil pressure, water temperature and fuel. If the gauge is the problem can I replace the fuel gauge part only?
4. Does the gauge come out without removing the dashboard?
5. If it's the sender I assume that I'll have to replace the full fuel pump and sender assembly? Is this relatively straightforward?

Thank you for any help.

Tony

They all do that Sir.
Seriously.

Use the trip. None of my cars had working guages

Sounds like a sender issue. The sender is integrated with fuel pump as you suspect. There is a large threaded flange at top of tank that allows unit to be unscrewed and removed. If you are willing to fault find the sender is a simple float operating on a potentiometer with slate/green and green/black wires carrying the signal to fuel gauge.

I agree with Richard, I'd be looking at the sender first. I replaced the sender in my 4/4 last year and was a bit surprised just how crude it was, just some windings around a piece of board with a wiper attached to a float arm. It was obvious how it had failed, the wiper arm seemed to have worn through the windings and it finally broke, leaving a rat's nest of fine wire.



Mind you, even after making sure the new sender was set up and calibrated correctly, I still much prefer to use the trip, refuelling every 250 miles. One thing the repaired fuel gauge has done though is to reassure me that I've still got a decent range above 250 miles should I need it.

Thank you. One concern I had when the problem occurred was establishing if the tank was full! From here you could be confident in the range via the trip. I've also been in Europe, I did 1600 miles and so wanted the largest range possible before refuelling. I worked on around 250 miles but as the tank hold 55 litres (350+ miles?) I couldn't help but think I was stopping more often than I ought to.

Surely just filling tank to fuel hose cutoff tells you it's full

My plus 4 is similar; it generally shows just over 3/4 with a full tank.
An alternative is to let it run to showing virtually empty…locally; ( carry a spare can if you’re worried about getting stranded), then go to a filling station and fill the tank until the pump cuts off.
Under those circumstances on my Plus4, I can only get about 37 litres or so in, so with a 55 litre tank, I have confidence that I can get at least 100 miles before getting concerned, even allowing for some that may not be pumpable in the bottom of the tank.

Not an issue for me, my bladder range is much less than that!

I know the feeling!