Smiths Fuel Gauge To Tank Sender

[timmacx]

I am in the process of updating the electrics on my roadster. I have installed a 52mm diameter Smiths Fuel gauge, this is to be mated to the existing fuel tank (which I believe is out of a mk2 Ford escort). The sender unit supplied with the gauge is a 2 pole unit fixed to the tank with 6 screws. The existing sender appears to be single pole push fit to tank. With the new gauge plugged in to the existing sender, an empty tank still registers half full on the gauge. Anybody know how to get an accurate fuel reading?

Can be contacted on 01389 849 105 if necessary.

[amalgamated users from prior forum]

Re: Smiths Fuel Gauge To Tank Sender

Message originally posted by: Don
Nope mines always been like that too. Any advice will be very welcome

[artrider50]

Re: Smiths Fuel Gauge To Tank Sender

Me too Learned to live with it, but indeed a solution would be nice!

[philcoyle]

Re: Smiths Fuel Gauge To Tank Sender

have you tried fixing an earth wire to the other connection

[amalgamated users from prior forum]

Re: Smiths Fuel Gauge To Tank Sender

Message originally posted by: Alan Hogg
I fitted a universal sender[see europa spares] and smiths fuel gauge when i built my roadster[escort tank] and had no problems with reading in relation to contents .You will need to wire thro' a voltage stabiliser this way

[amalgamated users from prior forum]

Re: Smiths Fuel Gauge To Tank Sender

Message originally posted by: Stefan Carlton
Mrk2 Fiesta Diesel sender on mine (as the old one sprung a leak).

But, who cares about a massively accurate level - all you need to know when your fuel is running low enough to warrant topping up and a linear motion to that point. In that light all I did was bend the bar on the float to ensure it was above the intake. Now should the guage start to read low, I know I have a bit left, but need to top up.

I made sure I didn't bend it too far mind, I get around ?24 @ 80p lt from a low tank and it's just the standard Ford Escort Mrk2 tank (8gallon)

[lil_red_roadster]

Re: Smiths Fuel Gauge To Tank Sender

I ran out at just under a 1/4 full just after finishing the car, so I know where empty is..! It's still on the "to do" list after 18 years but keeps getting pushed down to the bottom.

[h_m_cumming]

Re: Smiths Fuel Gauge To Tank Sender

I set the trip to zero when I fill it up and know that when I get to 140/150 I've still about a gallon+ left

[jon_cox]

Re: Smiths Fuel Gauge To Tank Sender

There are 3 or 4 different electrical standards for gauges and senders. The standards are normally expressed in terms of their ohmic values at the low and high end of the scale shown on the gauge. So a typical European standard would be 10 ohms at empty and 180 ohms at full for a fuel gauge/sender combination. In North America you may find gauges that are 240 ohms at empty and 33 ohms at full.
Smiths follow the European Standard, so if you have compatible senders, then that's fine, if you don't then you will need to use matching senders and although I've used a fuel gauge as an example, the same is true for all electrical temperature and pressure gauges as well.
It seems logical then that the Escort sender when in the empty position is giving a 90 ohm signal making your new gauge read half full. You could try an inline resistor but if the total "range" is not the same ie. 170 ohms, then your gauge may never read full. If I were you I would fit the new sender. You can get your gauges recalibrated but it costs abit.
Hope this helps.

[dogoncrazy]

Re: Smiths Fuel Gauge To Tank Sender

My son's roadster never read correctly,we tried an inline resistor to no avail.The car was sold and taken to Spain before we got round to sorting the problem!!

[amalgamated users from prior forum]

Re: Smiths Fuel Gauge To Tank Sender

Message originally posted by: CLive Harris
I obtained an Electric Fuel Guage from ETB instruments who matched the resistance of the fuel sender which was from a Sierra and then by setting the float to empty and noting the resistance and the same at the full reading it was then possible to have a fuel guage that read somewhere about 95% correct and so far in the 2 years after fitting I have not as yet run out of fuel. So try ETB Instruments they advertise in Kit Car and What Kit. Good Hunting

[dogoncrazy]

Re: Smiths Fuel Gauge To Tank Sender

Further proof that in can be done [from Clive Harris] why accept anything less

[robert]

Re: Smiths Fuel Gauge To Tank Sender

There is allegedly a degree of adjustment with these gauges. On the back you should see two holes with cork bungs in, behind which are two adjustment slots. Having said that, I’ve never tried it and on the gauge I have in front of me they are both solid and I’m not going to try too hard! I doubt that it would give much adjustment anyway - not enough to compensate for the wrong sender!
For reference, the gauge I have here requires 7.2V at 116mA for FULL and 1.4V at 23mA for EMPTY. This means the sender would need to be 23 ohms FULL and 370 ohms EMPTY (assuming a 10V supply and my maths being ok). Thats just my gauge or course, given the way they work I doubt if any two are similar!

[christineackroyd]

Re: Smiths Fuel Gauge To Tank Sender

I fitted my Ford Escort sender unit to my empty tank, but the fuel gauge read just under half, I overcame this problem quite simply by marking the position of the gauge needle when empty, I then marked it's position after adding a gallon of juice, I then coloured in my black faced gauge using one of those indelable black marker pens & carefully painted new positions on the face. Now this may not be entirely accurate throughout the whole range, but I do know when iv'e got a gallon left. And if you have a steady hand and are quite artistic it dos'nt look bad

[timmacx]

Re: Smiths Fuel Gauge To Tank Sender

Thank you all for your suggestions. This would appear to be a common problem, I'm more than a little surprised that manufacturers of these gauges, knowing that they could be used in kitcars with a wierd and wonderful tank configurations, have not addressed this issue. I'm hoping to get down to Stoneleigh (sans car, unfortunately) next weekend and hope to see you there for further discussion on the matter. Happy motoring to all!