MPG Meter for non-OBD Landys

I want MPG meters for my Defender and S2A but can't seem to find any parts to make them. RRs and Discos etc. have OBDs with computers and displays but I want to know how to add these features to my old motors. There must be lots of LRs which have fuel meters and some device for monitoring final drive revoltions but what are they and who supplies them? I can probably sort out the electronics for a display. Any thoughts from any of you good people out there?

Reset trip mile counter when you fill up and can easily work it out then

you'd need an ECU feed from the injectors letting you know how much is being pumped in, this would then need to be put through the odometer and into a transducer and signal conditioner in a wheatstone bridge to turn the signal from analogue to electrical, the distance related to the fuel injected could then be worked out via an algorithm giving you your mpg, this would then need to go through a signal conditioner again if wanted to make sure the readout was bang on

heres how u do it

fill up with fuel note how many gallons it is

drive till u run out of fuel,take a note of how many miles you did

then work out how many miles you did per gallon..no need for stooped computors

Dr_evil said:

you'd need an ECU feed from the injectors letting you know how much is being pumped in, this would then need to be put through the odometer and into a transducer and signal conditioner in a wheatstone bridge to turn the signal from analogue to electrical, the distance related to the fuel injected could then be worked out via an algorithm giving you your mpg, this would then need to go through a signal conditioner again if wanted to make sure the readout was bang on

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I don't think the s2a has the connector to plug the transducer into tho

wiltshire landyman said:

I don't think the s2a has the connector to plug the transducer into tho

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Only read the title must learn to stop doing that


If its for a 2a then you's buggered for the fender if running an ECU then it might be ok


Only way I can think of to do it on a S2 would be to guestimate and take a feed of injection rate from the rear of the pump and do most of it in analogue then convert later

Dr_evil said:

Only read the title must learn to stop doing that


If its for a 2a then you's buggered for the fender if running an ECU then it might be ok


Only way I can think of to do it on a S2 would be to guestimate and take a feed of injection rate from the rear of the pump and do most of it in analogue then convert later

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yep that would work

wiltshire landyman said:

yep that would work

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Still cant see why you'd want to tbh……..the point of a series is to have a basic vehicle with minimal leccy bits to fail

Or just use that little gauge with that needle on, when it gets near the red part and E go put some more juice in it ?

bencorkill said:

Or just use that little gauge with that needle on, when it gets near the red part and E go put some more juice in it ?

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my meter doesn't work on the series need to connect the fecker up once I gets that new fuel pump

Dr_evil said:

my meter doesn't work on the series need to connect the fecker up once I gets that new fuel pump

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I will get it out on weekend for you just gotta get the bloody tank guard off first!

bencorkill said:

I will get it out on weekend for you just gotta get the bloody tank guard off first!

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If you're planning on scrapping the tank fancy taking the thread that goes with the pump out of the tank too with about a 3 inch lip round it so I can clamp it down onto the current tank if not I'll have to find a way of making it fit without or fab up a new tank myself

Dr_evil said:

If you're planning on scrapping the tank fancy taking the thread that goes with the pump out of the tank too with about a 3 inch lip round it so I can clamp it down onto the current tank if not I'll have to find a way of making it fit without or fab up a new tank myself

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that may be possible, think some one was interested in whole tank :/ will giv it to u if i can

bencorkill said:

that may be possible, think some one was interested in whole tank :/ will giv it to u if i can

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Cool cheers mate

Yep, won't bother on the S2A. I don't think a 1996 Deffy has an ECU, only a Immobiliser & Alarm. Thinking about it I couldn't just measure the flow from the tank, the return from the leak-off from the injectors would have to be subtracted. How is it done on more modern Landys then? Perhaps I'll continue to use Wiltshire landyman's method - run it 'till its dry & check the odometer.

Its done how I said, flow rate through injectors is measured via the ECU and recorded against distance travelled

you don't need to run it dry at all. just fill it to the brim until 1st click at the pump and note the mileage. Do some driving till you've used at least half a tank, then go and brim it again to 1st click and note the mileage again.

ask for VAT receipt and you'll get the number of litres, which you can divide by 4.546 or similar to give the number of gallons.

Then take away the lower mileage from the higher mileage to give the number of miles, divide by the number of gallons calculated above and bingo.

However, the way fuel prices are going, it may be cheaper to go to a main dealer, and get the complete ecu and loom and ancilliaries from a rr sport and fit them to your vehicle than to brim the tank.

Then again, you could find a fuel flow meter somewhere on the web. Easy on a petrol, more complicated on a diesel as it has to work out the return as well and subtract. they do exist though.