Board logo

Fuel gauge dampening - Old skool way
sooty - 26/2/17 at 05:23 PM

Got a Smiths type fuel gauge, which get abit erratic when tank is half-full or less.

In the old skool days, I can remember fitting a capacitor or resister in the circuit to slow the fluctuation of the gauge.

If memory is right, a capacitor with fitted in parallel of approx. 400mf.

Correct/incorrect ??

gremlin1234 - 26/2/17 at 05:41 PM

quote:
Originally posted by sooty
Got a Smiths type fuel gauge, which get abit erratic when tank is half-full or less.

In the old skool days, I can remember fitting a capacitor or resister in the circuit to slow the fluctuation of the gauge.

If memory is right, a capacitor with fitted in parallel of approx. 400mf.

Correct/incorrect ??
I assume you mean 400uf, which should work nicely (use electrolytic at least 16v, preferably 25v rating )
but a regulator like the lm7812 or lm7810 would work better
http://uk.farnell.com/taiwan-semiconductor/ts7810cz/ic-v-reg-10v-7810-to-220-3/dp/7174020

edit:
I am sure there have been 'electronic' regulators available, which just replace the bi-metallic switching regulator.

[Edited on 26/2/17 by gremlin1234]

matt5964 - 26/2/17 at 08:30 PM

You could change the sender to a tube version

http://technisolltd.co.uk/products/fuel-sender-for-square-or-rectangular-tanks

https://www.merlinmotorsport.co.uk/s/instruments-gauges/vdo/vdo-dip-tube-senders

They will reduce the effect of sloshing fuel in part full tanks

sooty - 27/2/17 at 10:30 AM

Thanks,

But the sender and pick-up separately are on the side of the tank.

ken555 - 27/2/17 at 06:41 PM

The trick used to be fitting an old condenser from the distributer across the input and earth.

Had to do this on the Mini's otherwise you got spiky reading when cornering hard.

sooty - 6/3/17 at 09:59 PM

OK thanks,

Refreshing my memory, does the the condenser connect to the link between the sender and gauge and its body grounded.

thanks

ken555 - 6/3/17 at 11:34 PM

quote:
Originally posted by sooty
OK thanks,

Refreshing my memory, does the the condenser connect to the link between the sender and gauge and its body grounded.

thanks


From the gauge "input" from the sender to ground.

sooty - 7/3/17 at 04:14 PM

thanks