Hi all,
this question has probably cropped up before but has anyone fitted a low fuel level system to an MGF/TF?
I know they didn't have one on models up to the Chinese variant but I believe they may have been fitted to later cars.
You can approach this from several directions & I've tried most of them & until recently I've been dissatisfied with them all. I designed a simple comparator circuit which compared the gauge voltage with a present level & when the gauge voltage dropped to that of the preset an led would come on. This worked but was erratic, so I devised a more sophisticated idea with only slightly improved results. I then tried a non contact sensor on the tank & having taken the car to pieces to gain access to the tank, the device I'd chosen didn't operate on non conducive fluids. After more research (that stuff I should have done at the outset) I came up with a device which responded in a predictable way. It was world class at telling me that petrol sloshes around as a car travels down the road, even after I engineered hysteresis to counter the wayward response. I knew this could be problematic but not to the extent that it was.
Whilst scratching about looking for a better way of damping the system I found the answer & although its not covered many fill ups I'm happy that no amount of buggering about will improve things.
And I can't find reference to it just now because it's going on for eleven o'clock, I'm in bed & the information is in the workshop.
You'll have to wait until tomorrow. Mike.
This has all the makings of Airportable picture debarcle. I've just copied the e-Bay page for the low fuel device & it might just work, however - - - - - - - - - - - - - !
Works with a conventional gauge
will work on most vehicles that have a resistive sender
Does NOT need a special low fuel sender, works with ordinary senders!
Very small size (15 x 13 x 9mm) means it will fit INSIDE most fuel gauges or Instrument panels.
Turns on an :LED when the fuel level gets low.
Switch point fully adjustable.
Includes Wide viewing angle Water Clear 3mm RED LED and mounting bezel.
Works with senders that have a high resistance when empty
Works with senders that have a low resistance when empty.
tested with senders from 0 - 60 Ohms up to 0 - 500 Ohms
tested with senders from 60 - 0 Ohms up to 500 - 0 Ohms.
The module has four connections, Power, ground, sensor and LED.
When fitted inside a stand-alone gauge, no external connections required
The module has an anti-slosh circuit that makes it respond very slowly to changes in the sender signal.
this means it ignores the changes due to fuel sloshing in the tank or short hills etc.
Adjustment is by turning the small adjusting screw on the high quality 25 turn trimmer
Full instructions included
provided with double sided tape on the rear for fixing
four connections, +12, Ground, Sender, LED
every unit hand built, and tested by us!
for the technically minded, all except the 25 turn potentiometer are surface mount components
the capacitors are not electrolytics that have a limited lifetime, but multi-layer ceramic caps that will outlast the car !
This unit is the latest in a long line of low fuel warning modules we have designed and it incorporates everything we have learned.
below is what it looks like in a TVR/Telemetrix fuel gauge.... there is more than enough room!
In the example below, the supplied LED bezel was discarded and silicone used to fix the LED
Business seller information
Spiyda Ltd
Chris Horne
54 Bridgnorth Road
Wollaston
Stourbridge
West Midlands
DY8 3QG
United Kingdom
thank you for your response on this, obviously this will give me a low level warning but do you know if it will also make the fuel gauge more realistic and user friendly .
To just add something to the fuel level oddities of the MGF/TF ,I have a MGTF fascia on my bench to trace out the wiring to cure a problem with the boot open warning not operating and asked my wife to just watch the warning lights while I wired up a battery to test with and she said I hade a full tank of fuel !!
So why does the fuel gauge sit where it is resting after a drive ,most other vehicles return to zero.?
Realistic, user friendly, crikey this is MG Rover parts bin plunderers we’re discussing. Fit the low fuel warning & be thankful you aren’t going run out of petrol. (Much).
The diagram shows three connections to the movement two polarising & one from the sender which is on the earthy side. I suspect that there’ll be a holding magnet in the movement retaining the indicator in the last position after the polarising voltage has been removed.
Can it be modified to operate normally? I could find out but it’d be very low down on the jobs list, however the first thing I would do is remove the negative pole off the movement.
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