lpg led indicators/sender unit the mechanical one on tank is fine.
But the damn led one reads as it feels like,ie never empty when tank is and even reads full when tank empty-it's not the wiring as pulling the sender plug displays empty.

I've seen sender units on the internet, are they all 0-90ohm or can led gauges be calibrated or tank tapped to free it

I think they're all like that, TBH.

Bloke that finds a 'cure' to the guess guage will cause a stampede!

I think that it's as much as anything a sensitivity 'thing';

The led guages seem are a lot more sensitive than a mechanical guage, so they dont have the self damping in the system to stop them bouncing about widly as the fuel in the tanks sloshes about and stuff

So they have electrical damping in the system to make the reading a bit more 'stable' and that makes them that much more innacurate.

Guage on the tank, tends only to get viewed when the car is stopped, so it's giving a stable reading, on the move, probably all over the place.

Seems that guages on smaller tank and multi-tank systems give 'more' reliable readings, more often, than big tank systems, so It sort of supports the idea that a big bit of it is the fact that the tanks aren't baffled, and the fact that they read pressure rather than depth.

Anyway..... oddometer....... reset when you top your tanks up, know your 'range'........ and keep the FPF Tank 1/4 full 'just in case'!

Having said that, managed to catch myself out a few times still; ran out of petrol on the M5 once..... had done 200 miles in one stretch, guess guage hadn't budged from full........ sat on the hard shoulder, scratching my head a full five minutes staring at the dash, feathering the throttle thinking a Head gasket must have 'gone' until realisation 'dawned', and I recognised the anomoly of 200 miles on the trip and a full LPG tank!

it's strange it read low before and swaped to petrol, now it's as much use as a chocolate fire guard, I'll put a meter on it as I would have thought it is nothing more than a potentiometer on the mechanical guage

Ignore them, they are notoriously unreliable.
Fill with LPG, zero the trip, run on LPG until empty. Note trip reading. Then zero the trip each time you fill.

fanatic said:

it's strange it read low before and swaped to petrol, now it's as much use as a chocolate fire guard, I'll put a meter on it as I would have thought it is nothing more than a potentiometer on the mechanical guage

Click to expand...

As I understand it, its a pressure transduser for the LED's and a recalibrated pressure guage for the mechanical tank dial. Hence the unreliability.
Petrol guages read the level of the tank from a ballcock on a pottentiomenter, but with gas sure its done on pressure, hence the vaguary, as they are really only accurate when the tanks are close to full, when they are getting empty pressure doesn't change by very much, in proportion to the change in volume.

Mine's pretty accuate, leave it untill red light comes on then I've got about 20 miles left.
I use the trip but after filling, four lights means over three quarters, three means over half etc and when two lights I have gone approx half distance, cant fault it.

there is a potentiometer connected to a mechanical guage, mine is reading 1.6 ohm at the moment, but I can get a replacement for £12 if the people that fitted the system in january won't play

Mine's hopeless. Reads empty after about 60 miles, yet I reliably get 225 miles out a tank (strangely it doesn't matter how I drive be it onroad/offroad/ low ratio whatever - I ALWAYS get 225 miles out of it.) The beeping when it's empty works fine though - I assume this is guaged differently to the LEDs.

The odometer is the only reliable way to judge what's left in the tank.

Apparently they're all like that.

Guy

yeah, had 2 v8's on lpg one mech gauge on side of external tank, one led type dash gauge, always had to use the trip counter.