working fuel gauge on a Rover 213/216 unit

[kelvink]

If I bought a rover 213 petrol tank and filled it with water connected a battery to it and measured the voltage from the sender unit and then filled the Midas and checked the voltage on my tank would that then give us the difference we need to work out how to solve this problem

You wouldn't need to have a tank, just the sender would do to find out what the difference between empty and full. But when you've got yourself the sender you might find that it may fit the Midas tank too, in which case just fit it and problem solved.... Somehow I doubt it's this simple though

[b1zbaz]

Sorry about the lack of reply I did not realise there was a new post I'm going to try sort the temp sender issue and fuel gauge as I'm pretty sure the a lot of ppl on here will be happy to find the answer but I need a little nudge in the right direction if it was anything to do with timber I could get it done in an instant

[Hans Efde]

Well, I've had a look at some resistor colour charts, but I'm not entirely sure about the values I get; mainly because I'm not sure I'veinterpreted the colours in Hans's photos correctly!

The blue resistor looks to me like it's red, violet, black, black, red, which I believe makes it 270 ohms with a tolerance of +/-2%.
The buff resistor looks like brown, grey, black, gold which translates to 18 ohms, tolerance +/-5%. However I'm not sure I have the colours of the first and third bands correctly, the third one might be brown, which would mean the first band is probably red or even orange. I think I'd have to see the actual resistor to be certain - preferably with a multimeter to be on the safe side!

Yesterday I removed my tank for a sealant job and improvement of the breathing. Since now the gauge was disconnected I could measure the resistance of the bleu resistor. And you were spot on, it's exactly 270 ohms. So if you want to get a reliable reading on your Rover 213 display you have to solder in a resitance of 20 ohms and one of 270 ohms.

[DavidL]

Well, I've had a look at some resistor colour charts, but I'm not entirely sure about the values I get; mainly because I'm not sure I'veinterpreted the colours in Hans's photos correctly!

The blue resistor looks to me like it's red, violet, black, black, red, which I believe makes it 270 ohms with a tolerance of +/-2%.
The buff resistor looks like brown, grey, black, gold which translates to 18 ohms, tolerance +/-5%. However I'm not sure I have the colours of the first and third bands correctly, the third one might be brown, which would mean the first band is probably red or even orange. I think I'd have to see the actual resistor to be certain - preferably with a multimeter to be on the safe side!

Yesterday I removed my tank for a sealant job and improvement of the breathing. Since now the gauge was disconnected I could measure the resistance of the bleu resistor. And you were spot on, it's exactly 270 ohms. So if you want to get a reliable reading on your Rover 213 display you have to solder in a resitance of 20 ohms and one of 270 ohms.

Fantastic, Hans, thank you VERY much. It will be good to have properly working gauges for the first time since I got the car, about 18 months ago!

[mikeeskriett]

I couldn't figure it out via the diagram from the pics but is it in effect creating a Wheatstone Bridge to drive the gauge? I'm dusting off my electronics books to try and make the MGF pack in my Mk2 read accurately as it's reading 3/4 when the tank is brimmed. The same technique is used in 60's aircraft gauges.

Cheers,

Mike

[mikeeskriett]

Or come to think of it a potential divder?

[DavidL]

I went to Maplins to buy those two values of resistor, but found out later, when i checked them, that they'd picked out and sold me the wrong values. Haven't had time to go back since.

However, a convertible owner I met at one of Alistair's open days, probably 2 years ago, mentioned that he'd fitted Metro fuel and temperature gauges into his Rover 213 instrument panel, which gave correct readings without any additional resistors. Having bought a pair of those from an Austin Metro, I have deduced that it's the gauges from a Rover Metro that would be needed. And I've just missed a Rover Metro at my local scrapyard...

[Rich]

I may have some Mk2 guages kicking about still.

[DavidL]

By Mark 2, do you mean Midas Mark 2 or Mark 2 Metro (i.e., Rover Metro)? If the latter, there could be money in it for you...

[Hans Efde]

I went to Maplins to buy those two values of resistor, but found out later, when i checked them, that they'd picked out and sold me the wrong values. Haven't had time to go back since.

However, a convertible owner I met at one of Alistair's open days, probably 2 years ago, mentioned that he'd fitted Metro fuel and temperature gauges into his Rover 213 instrument panel, which gave correct readings without any additional resistors. Having bought a pair of those from an Austin Metro, I have deduced that it's the gauges from a Rover Metro that would be needed. And I've just missed a Rover Metro at my local scrapyard...

That may be a much better idea. Now I am on the road again I find the indicator pointing to zero fuel, but there is still some juice left. I even did 100km with the needle already in the red zone. When the tank is full, the needle indicates full. But it drops too quickly, something I hadn't before the renovation. Possibly I bent the arm of the tank sensor at installation. Since the fuel consumption is still not completely determined, it's also difficult to work out the milage so I can use the ODOmeter. Therefore I am going to put a 5 ltr jerrycan with spare fuel in the boot.