Guys,
One of the problems I thought I might face has appeared......
As you probably know, I'm running a set of type 3 clocks, including the fuel gauge. The tank and sender are type 1 beetle stuff. The two do work together, just not very well. I've adjusted the float on the arm so that it reads empty and full on the t3 gauge when empty or full etc but the problem I'm facing is the gauge swinging about all over the place whilst driving down the road.
Thought this might happen as the type 3 senders are different (cylinder type affair) which don't really suffer with the fuel slopping about like the beetles did. The type 1 gauge has some clever electrics in it (heater and bi-metallic strip) that dampen out the signal from the sender to give a much more steady gauge.
So the question I'm asking is that is there anything I can do to overcome this with the t3 gauge/t1 sender set up. Speedy Jim over on VZi ( a very clever electrical bloke) has suggested a capacitor, between the fuel gauge input and the earth on the gauge might help the issue.
Just wondered if anyone else had any ideas? I did speak with Mark at Flatlands as I know he has built a few with Type 3 gauges but he has someone do all the electrics for him and didn't know how it was set up.
If the level of fuel is accurrate, ie reads full when full and empty when empty, and the problem is that the needle needs "dampening" somehow. Not strictly as simple as a capacitor, but along those lines.
Might be worth a chat with the guys that do the fuel sender matching units, to see if one of these would overcome the problems and damp the needle movements?
http://www.ebay.co.uk/itm/Fuel-Gauge-Wizard-Matches-Gauge-to-sender-petrol-diesel-lpg-oil-water-etc-/251240184459?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a7f14fa8b
Hopefully this can sort my dodgie readings from my gauge. Good thing I looked this up before taking a punt on a custom fuel tank!
There are youtube destruction on how to install it, looks reasonably easy!
I was pointed in the direction of this type of thing. I borrowed one as my tank has been "modified" by bashing to clear the track rod beams etc and the tank sits on a slope. I will be getting my own as when attached the result is surprisingly accurate.
Chads your man his mate does a box where you dial in the sender ohms then adjust the needle to suit the reading, about £45 and a bit fiddly to calibrate but they do work.
can you not try a voltage stabiliser
from a t1
I have now used 3 of these Spiyda Gauge Wizards and they are brilliant.
The best one was using a beetle sender with a generic unknown gauge someone had bought of e-bay. Got it to read spot on.
The latest MK4 one looks better that the MK3 I used in that it has pre-wired tales on it. The Mk3 you had to get wires into tiny little holders and use a micro screwdriver.
As for setting the gauge I threw away the small adjustable resistor that came with the wizard and did it the old fashioned way.
Basically fit the tank in the car, and wthout the sender in, fill with fuel (or water) until the fuel just comes up to the hole where the sender goes. Filling passed this point will undoubtedly cause some fuel leakage through the sender when driving. Alternatively fill until fuel comes out of the filler neck (if this is at a lower point than the sender hole.).
Now empty the tank by pulling the pipe off the chassis and emptying into cans. When it stops coming out that's your zero point (there will be some fuel left in the tank but due to the angle of a buggy shell where the tank sits, this will be below the outlet on the tank).
Make a note of the total amount of fuel your tank holds - on a Doon this is around 30 to 35 litres depending how lowered the front is :D
Now take the tank out and drain out the residual fuel. Make a note of this volume too. Around 1.5 litres in a Doon.
Fit tank back in, fit sender, wire up the gauge wizard as instructed. Pour back in the first residual amount of fuel (1,5v litre in the Doon). This is now your true 'empty' point .. i.e the point where your buggy would run out of fuel as this fuel sits just below the outlet of the tank. Then set your fuel gauge to zero following the instructions.
Now for example say your tank holds 30 litres as measured above. Simply pour in 7.5 litres and set the gauge to 1/4. Put in another 7,5 litres (15 total) and set gauge to 1/2, another 7.5 litres, set gauge to 3/4 and final 7.5 litres and set gauge to full. This way you get a 'true' ohm reading off the sender to the gauge taking in the resistance of the wires between the sender and gauge.
By simply using a meter to read the ohm settings of the sender at empty and fuel, then simply using a linear scale between the two to set 1/4, 1/2 and 3/4 using the variable resister that is supplied doesn't work. Why? because I have found the beetle sender doesn't particularly give a linear reading as it rises and falls.
By using the fuel filling method above ensures that when the gauge reads half, the useable space in the tank is half full and when it reads empty it is at the point you are about to run out of fuel.
I hope this makes sense?
I have to say the three I have done this way have given the truest fuel gauge readings I have ever known on a buggy.
Chad
This point Chad makes of the sender unit resistance winding not being very linear is what I found also.
Continuing on from this, do I need to use the Voltage stabiliser on the fuel gauge if I am using the little black box?
The stabiliser just stops the needle fluctuating with the charging voltage so 1/2 full is still 1/2 full with the engine running with 14v output.
Hmmm.
I seem to have done something wrong. Shock horror...
Got 5l of fuel in so i am setting the empty position on the gauge.
Set the gauge wizard to flash 1 time for storing empty position and store it.
I then adjust needle using the wee box and set it to sit onto the red.
Soon as the box saves this needle position it goes and reaches maximum...
Blahhh
Just seen a puff of smoke come out the fuel sender when trying to set 3/4.
Not today..... ::) bleugh bleugh bleugh
Giving up
Started setting one up on buggysteves for him last year but did not get it fully sorted as ideally you need to part fill the tank for the 0, 1/4, 1/2, 3/4 and full ohm readings.
Put these into the unit then set the gauge to them and calibrate the needle. Draining the full tank is not easy so removing the sender to check the range is the easiest way after.
Suppose if you had enough storage you could start with a full tank calibrate on emptying then test on the refill.
Biggest issue I have with the fuel gauge on mine is that because of the angle there is no way that I can see of getting the float to travel from the lowest point to the highest. I can either have a gauge that reads empty at 1/4 tank and is accurate to full or reads full to 3/4 tank then is reasonable down to empty - I have settled on the latter.
Bending the arm either has it bottoming out on the angle with loads left or hitting the angled top of the tank well before full
Just carry a gallon can ;-)up cheap and the fuel in it will probably go up in value
That was the idea to overcome the sender issues.
Just cant get it to set correctly. Batteries flat now so will look at it next week maybe. One more try then if not it'll be guess work like before!
Quote from: apmaman on March 09, 2018, 03:52:26 PM
That was the idea to overcome the sender issues.
Just cant get it to set correctly. Batteries flat now so will look at it next week maybe. One more try then if not it'll be guess work like before!
you tell then adaptor 5? points of fill on the sender unit you do the same with the gauge then so they can talk then set the needle to the ohms from memory a clever bit of kit just takes time to calibrate. you just need the ohms readings for the sender and gauge in various positions then the unit is used to match them.
Yeah this one as a setting so you can set whatever the sender reading currently is to a defined point.
So i knew i had 5l in. I wanted to save it as tank empty. Saved it. Moved on to 10l in tank. Saved sender reading as quarter... etc etc then i set the gauge needle to each saved point but it wont work out.
Tried cailbrating that way from empty to full.... no joy
Calibrated from full to empty. Again no joy.
How do u get the ohms from the sender? Iv a multi meter but I cant remove it without taking half the car apart.
Last ditched effort before i fling the box in the bin haha!
That is why I could not finish it off as I would have had to strip the bonnet and screen off so left it to buggysteve over the winter. He had a type 3 gauge and beetle sender. The ohms resistance to tank contents is not linear and I did not have a spare beetle sender to use on the bench to play with but the beetle is 0 ohms full to 90 ohms empty the T3 was 0 empty and 75 ohms full thinking about it sat here.
I think a bit of trial and error is involved but with parts on the bench it would be simple to check the calibration through out the range.
Cheers Snoopy.
Will give it a bash tomorrow with the ohm inputs rather than the "quick" method. Here's hoping! Even if I get the needle to be on the red at the correct level I'll be happy as thats the most important part.
from memory it was ohm meter on a pin or wire then adjust the empty to full pots to get the relevant ohms reading you had taken off the sender then you did the gauge empty and full ohms then set the needle position on another pot. took me a few times of reading to get to grips with it.
Surely there's no need to dismantle.
Measure the resistance to earth where the adjustment gadget will be and buy a potentiometer of the appropriate range. Use your meter to set the pot for empty and connect the pot between earth and the gadget and adjust the gadget till the gauge reads right. Repeat for the other settings.
So long as sender is good and there is a good earth on it should work with no dismantling
You need to drain and refill the fuel tank to get it right as you cannot get to move the sender with a wire down the filler. a good bit of kit but setting up is a bit involved. My gauge reads full on the vw sender until I hit 2 gallons left in the tank then it starts moving down and is empty at 3/4 but that is fine as I know.
Quote from: snoopy on March 10, 2018, 08:21:00 AM
You need to drain and refill the fuel tank to get it right as you cannot get to move the sender with a wire down the filler. a good bit of kit but setting up is a bit involved. My gauge reads full on the vw sender until I hit 2 gallons left in the tank then it starts moving down and is empty at 3/4 but that is fine as I know.
Surely draining to the empty point can be done without dismantling from underneath and I know you can refill without dismantling I have seen you do it :-\
Well been at it again all day today.
No joys. I tried some of the preset settings as well to see if anything worked but no joys on any of them either.
I tried again to get the ohms from the sender with the multi meter -ve in -ve of sender wire. +ve multimeter in sender output that goes to the gauge but I couldn't get a reading no matter what.
Putting the sender back as "stock" works, as in it usually does. Reads empty after using 10l of the 25l capacity, so the sender is ok. I must be measuring it wrong. But thats how I remember doing it, take the sender (variable resistor) out the circuit so that can't interfere and moving the sender should alter the resistance... I duno. Maybe the fumes from all that petrol has gotten to me!!
Giving up on this wee box until I find the enthusiasm (or someone that knows what they are doing!!!!) to get at it again.
You test the sender omhs from the mounting plate to the feed terminal, the ohm meter needs to read 0 - 100 ohms and for absolute accuracy ( not required for this )you should include the wire to the new box and onto the buggy chassis earth so it covers all parts of the circuit
I have 2 wires from the sender in the tank. One brown negative the other orange grey to the gauge.
The multimeter -ve is poked into the terminal on the wire of the ground wire and +ve on the multimeter goes into the terminal for the orange grey that went to the gauge.
No matter what i fill it doesnt change or make a reading....?
Im using these wires off the sender cause i cant physically get to the sender posts unless i develop octopus arms ;D
One last ditch attempt today to get some kind of readings out the sender then i have no idea what to do.
Sorry if I am teaching you to suck eggs but
You need the multimeter set to a low range, otherwise it will probably just look like a short.
If the meter is working (crude test check across a spare bulb) and there is still no change them suggests a break in the circuit or a knackered sender. My last sender from GSF only lasted a few years then the resistance coil broke and it was history. Read over part of the range, then stuck on the break
Good luck
Quote from: Doon L001 on March 11, 2018, 01:01:33 PM
Sorry if I am teaching you to suck eggs but
You need the multimeter set to a low range, otherwise it will probably just look like a short.
If the meter is working (crude test check across a spare bulb) and there is still no change them suggests a break in the circuit or a knackered sender. My last sender from GSF only lasted a few years then the resistance coil broke and it was history. Read over part of the range, then stuck on the break
Good luck
Ah no egg sucking here. No worrys about that. I got donated a "fluke" from a chap i use to work with so i knew it was me or the buggy.
I have found the problem though.
After a lot of faffing to spidermanning my arms onto the sender and brimming reads only 16 ohms..., and after draining 3 !! 3 Litres it reads 0.. draining any more just gets an error. So the sender must be maxing out inside the tank from the angle of the tank and the senders position.. Or its f...ered.
As i was draining 5l each time to check i never knew where it was going bad. Since i did 1l at a time i found my problem.
Explains why the tank read empty after about 50 miles too.
Ahh well. Im not taking the front half apart, fook that.
Sounds like the same problem I had when my sender failed. Tank angle also stops full travel on mine
All the best
Dave
the Jas sender failed after 6 months that was from a VW supplier not GSF so it gets brimmed at 150 miles.as like you I cannot be bothered to strip and renew it again.
;-)up ;-)up ;-)up ;-)up
That it snoopy. I did want to fix it, my only real issue I have with it tbh, otherwise its a right hoot! but the hassle to change the sender etc not really worth while. I managed an 100 mile a stop on IBW etc and still had 10l left. Now I know what the actual capacity is I'd say its good for 200 miles, but no doubt just keep to the 100/150 mark to be safe.
So the gadget is up for sale if anyone wants it