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MG MGA - Fuel tank dipstick

I have just seen the recent thread about calibrating the sump dipstick and it reminded me that I intended to ask if anyone had ever made and calibrated a dipstick for the fuel tank in imperial gallons?

I have a fuel gauge that shows full when the tank is full and then drops steadily down to half full when the tank is empty. So it gives only an approx indication of fuel levels. I just watch the mileometer and once I get to 200 miles I begin to look for a fuel station. So until such times as anyone makes an accurate replacement fuel sender, the dipstick seems the obvious alternative.

I began to make a wooden dipstick for the tank and I have marked onto it the position of the top of the tank as the "Full" mark. ( I measured down through the neck with a tape measure to find the top )

The problem is calibrating the stick as it would involve adding 10 accurately measured gallons one at a time and marking each level on the stick.

I could just measure and mark the dipstick into 10 equal sections I suppose, but the fuel tanks are not perfectly rectangular and so I dont think this would be particularly accurate.

Colyn

c firth

Colyn

It's bit of a problem with such a shallow tank. Unless you are on absolutely flat ground each time you will get erroneous readings. You could always adopt the ancient mariner's method of a bit of cord with a lead weight and tie a knot for each gallon! Or perhaps tap a hole at the bottom of the side (below the sender unit?) and attach an optical (Clear plastic?) vertical tube to observe the level.

Steve
Steve Gyles

Colyn, Are you sure the problem with your fuel gauge circuit is the sender unit because it could be the gauge itself?
If you've got a multimeter find out what resistance there is across the sender unit (first disconnect the GB wire) when empty and full and this should be around a few ohms when empty and around eighty ohms when full. If you find this then your sender unit is fine and you should recalibrate your gauge..................Mike
m.j. moore

I calibrated a stick that reads 5, 10 & 15 litres that I keep in my car mainly to help others with dodgey fuel gauges. Do you want these measurements?
Mike
Mike Ellsmore

Mike..that would be good to have as a cross check. I don't run out of fuel as I limit my mileage between fills. I don't trust the gauge.
Neil Ferguson

Here is what I made to get a reading in my B-GT

David Werblow

Colyn, my fuel gauge if "off" as well, and I took a bit of a different approach to estimating the amount of fuel I have. I used the faceplate from a very damaged fuel gauge as my measuring stick. I first emptied the fuel tank and then added a gallon at a time; with each movement of the car's fuel gauge I made a mark on the spare fuel gauge indicating how many actual gallons there were in the tank. When my car's gauge reads 1/4 full, I now know that I have about 1.5 gallons remaining; at 1/2, there are about 4 gallons, and so on. I carry this spare gauge face in the car with me at all times and it has been a very reliable estimating tool. While this method may not work in all cases, it may be of help to others with similar issues.
Nick Kopernik

Would this be a possibility
https://www.spiyda.com/magento/index.php/fuel-gauge-wizard-mk2.html

Or make your own?
https://sites.google.com/site/shannonpowerlab2/home/calibrating-your-fuel-gauge
Neil MG

Neil..Now that I like....may even solve my needle bounce problem. Pity is so steep a price ..
Neil Ferguson

Mike
I would appreciate your sending the calibrations for the tank dipstick, it would be useful to compare with the measurements I took of my tank.

Nick
it looks like I am going to have to get 10 one gallon containers and calibrate my gauge and a dipstick at the same time.
Good idea about making a new face for the gauge.

Cheers

Colyn
c firth

I know I have a dodgy sender unit, which I think suffers the intermittent shaft bearing earthing problem. Sometimes its just nice to get a positive idea of how much fuel you have in there. To this end I use a straight piece of 1/4" dia wooden dowel which reaches the bottom of the tank, simply marked at the full position. The wet fuel shows clearly as the dowel is darkened by it. If its wet about half way up, I know its not exactly 5 gallons but who cares, it'll get me to the MG club night and back. This dowel dip stick also fits neatly out of the way in the boot.
Pete
PeteT

I know I have a dodgy sender unit, which I think suffers the intermittent shaft bearing earthing problem.
Sometimes its just nice to get a positive idea of how much fuel you have in there. To this end I use a straight piece of 1/4" dia wooden dowel, I happened to have, which reaches the bottom of the tank, simply marked at the full position. The wet fuel shows clearly as the dowel is darkened by it. If its wet about half way up, I know its not exactly 5 gallons but who cares, it might, for instance, get me to the MG club night and back. This dowel dip stick also fits neatly along the side of the boot.
Pete
PeteT

Neil, Colyn and others,
Attached is a photo of my MGA fuel tank dipstick (600 long 9 x 9 dowel from Bunnings). The 5 litre mark is 52 mm from the end then another 26 mm to the 10 litre mark and another 25 mm to the 15 litre mark (yeah, the 5 litre mark seems odd but I checked it several times when making the stick, assume it has to do with the curved base of the tank). (The stick is inclined 50 deg to the horizontal when in the tank - thanks to my iPhone level!). I keep it in the dead space behind the boot catch in the rear valance.
As I said earlier, it is mostly used for helping others out as I am aware of my own gauge idiosyncrasies.
Mike

Mike Ellsmore

Thought I'd reactivate the post with my updated Fuel Dipstick measurements.

P Draycott

If you have a TD you probably have one of these. I don't think this can go down the filer tube in my MGB or my MGA and, or course, the graduations are not relevant. Perhaps none of this posting is relevant but, what the heck...
My problem is that my MGB stops accepting gas (the automatic filler thingy shuts off) when, according to the gauge, the tank is only 3/4 full. Someday I'll need to drain the tank and refill it with known amounts to determine whether it really full when the gauge says 3/4 or if something is preventing the tank from really getting full. In the meantime, like others, I just try not to go more than 200 miles between fill-ups.

Jud





J K Chapin

Thanks for the reply Jud. I use a 600mm 3/8 inch dowel similar to Mike's.
Owning a MGA is like owning an electric car, you're never quite sure how far you will get.
P Draycott

But it's a helluva lot more fun!
J K Chapin

Hi Colyn

I also use a piece of dowel. It has bottom cut at an angle so it always sits the same way. I have it calibrated each 2 gallons.. I did this by emptying the tank and refilling it in measured 2 gallons. Interestingly it still shows half a gallon if you run out of petrol so beware.

Hope to see you on the road some time.

Paul

Paul Dean

This thread was discussed between 17/09/2014 and 03/09/2024

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