The needle in fuel gauge is constantly waving / moving and it is hard to work out how much fuel is actually in the tank.
It is only steady when the car is not moving, but I am never sure I can trust where it stops.
So far I haven't run out of fuel but would obviously prefer to fix the issue rather than put up with it.
Has anyone had similar problems or knows how to fix the problem?
Thanks Ash
This seems like a common thing among older Alfa's, mine does it, and so does my brothers cars. Its almost like a game haha, see how high or low u can get it goin around a corner :D
My 1750 GTV also features this endearing 'characteristic'. I have resorted to using the trip meter as a guide.
At 140 miles of normal driving, I have already thought about where the next petrol station might be. On the highway, its at 180-200 miles. Track days are harder, so I wait until the red light has started to flicker. If it stays on, I start to sweat. I am unsure if my target miles are conservative but I don't run out of fuel.
This strategy also helps avoid picking up the rubbish that sits at the bottom of the tank.
I find this the 'cheapest' method of dealing with the problem.
Cheers,
Marco
There is an easy fix to the wavering needle. You may have noticed that 2000 GTV's don't do it.
It is just a matter of fitting a resistor (choke) across the fuel gauge in the dash. This produces a permanent current when the key is on that centres the gauge needle, which then uses the float in the tank to vary the gauge position, but taking a few seconds to do so. a few. Thus the stable needle.
It takes a bit of experimentation to get the right resistor. If I can find the article that was published in our club magazine a few years ago, I will post the link on this site.
Interested to see the mechanics of this fix Gary as i have the problemin my 116 GTV too.
Thanks for the feedback, starting to realise the old car has many "endearing qualities", many of which I would ideally like to iron out, without sacrificing the 105 charm.
Looking fwd to the post / link from Gary and fixing the problem.
In reading Gary's post it's is still the amount the float moves that shifts the needle and the resistor just "dulls / slows" the movement. So should the float & hence the needle be moving so much? Or is it as everyone keeps saying another quirk of the older Alfas ...
Is there a spring or the like that stiffens up the float mechanism, that might have broken or worn that would stop the rapid movement?? ??? Just guessing here but they were my initial thoughts.
I also have this issue, if it's as simple as getting the right resistor and soldering it in place i would be very interested to try it. It's really so when people (other than myself) are in the car don't freak when the red light flickers...
I would be hesitant to pull out the sender unit and start playing with the mechanism - you will most probabaly find no spring on the sender anyway.
Adrian.
Yes you are right Ash. The mod just slows up the movement only. Seems pretty good though. There is no alteration to the float system and I don't think a spring of any kind would work.
I still can't find the write up, but I have also experimented reasonably well with connecting a low wattage globe across the back of the fuel gauge. Takes a bit of experimentation to get it right and there is a dull glimmer from the globe that may not suit everyone, so the resistor (and the diode) is the solution I believe.
I've pulled a lot of these senders apart and there is no spring, its just a pivoting arm, I don't think a spring would be the answer anyway as your looking for a some damping in the movement
Not having pulled the sender out as yet, I am surprised that it's just a free floating arm with no counter resistance. :-\
Thought there may originally been have been a retardant of some kind to slow the rapid rise and fall.
Perhaps adding a small amount of weight to the end of the arm of the sender might work?? ???
Then again adding a resistor at the back of the gauge sounds a whole lot easier ! ;D
Gary, i remebered the idea of a resistor for my fuel gauge the other day - did you have any luck finding the article regarding what sort of resistor and where to put it?
Adrian
Me too !! It really is a 1750 GTV problem, the fuel gauge, since mine too also has an endearing quality. Mine though is a little different in as much as when the tank is full it only ever at best reads 1/2 full. So it becomes a bit of guessing game as to when it is really empty. I think the red warning light does work but as my trip meter doesn't work I generally work on the theory that when the guage reads empty, I have roughly 1/2 a tank. So far in 12 years ownership I havn't ever run out of fuel, but possibly more by good luck than anything else.
I would be interested if anyone has any ideas why my gauge never registers as full. Dave
Yes sorry Adrian.
I can't find that article, I was sure it was in Cross & Serpent a few years back.
Here is what I did initially to fix the problem in my Giulia Sprint GT.
I used a simple dash light globe (about a 4 or 6 watt 12v globe) and soldered two wires onto the globe to afix across the tank unit wire on the back of the instrument. It took a bit of experimentation with different wattage globes. With the next car I went to a techno-wiz (Jaycar I think) to give me a resistor to match what I wanted. It is too hard now for me to pull the gauges out of my race car due to the cage so I can't help you much more than that right now.
Part two to this is real easy to fix. Fuel gauge and warning light acuracy.
1) Just unscrew the tank unit from the top of the tank in the boot. 6 screws. You might need to disconnect the fuel pipe and the two wires before lifting out the tank unit. 5 mins. so far.
2) Now connect up the two wires again, also connect a tempoary earth wire between the (now removed) tank unit and a suitable clean earth connection. (maybe the boot latch)
3) Turn the key on.
4) While holding the tank unit in your hand, you can watch the dash gauge through the back window, you can move the float leven through it's travel and see the appropriate movement on your dash gauge. A bit easier to do with two people, but I like to do it myself so I can see exactly where it is reading. 10 mins now.
5) Stick a measuring stick in the tank through the fuel gauge hole and measure the level of fuel remaining. Draw a conclusion on how much fuel you have (say 1/2 tank)
6) Measure the travel of the float on the gauge unit, noting when the light comes on.
7) Vevy gently bend the wire arm holding the float to match what fuel level you have, and where you would like the fuel light to come on. 15 minuites all up.
A couple of trials are usually required to get what you desire, but I haven't had much trouble geting an accurate gauge this way, with a light that comes on at about 8-10 litres to go.
Some care issues.
Make sure your fuel tank is securely earthed to the body with clean shiney screws or you will get voltage drop and the gauge will be inaccurate.
Make sure the plastic float is air tight. (shake it, or push it in a glass of water to see if any bubbles can be squeezed out)
There is no safety risk in doing this opperation providing you are doing it on a cool day. It is pretty hard to ignight fuel with a spark, as it is FUEL VAPOUR that is dangerous, but just be causious with ventilation and securing earth connections befor turning on the key.
All up 30 minuites and you should have a more accurate 105 fuel reading.
Nice little tip there Gary. Cheers
Gary thanks for these tips, makes sense in regards to the adjustment of the sender to modify when the red light comes on and adjusting the speed of movement in the gauge.
My guage is actually jumping forward and backward a bit as I drive making me think i have a dodgy earth somewhere (which i have redone at the fuel tank) or inconsistent voltage. I can put include some resistence through the violet colour fuel gage wire as you described but i dont think that will solve my problem.
I plan to get the multimeter out and check some voltages, if its jumping around a lot i may need to look at a new voltage reg and/or earthing issues.
Adrian
Hi Adrian, the most likely causes are:
1) the float in the tank. If the plastic container (float) is full of petrol it fluctuates widely.
2) the spring tension on the tank unit resistor is not sufficient throughout the span, causing open circuits. Bend it in.
3) the earthing on the fuel tank (and or) the earthing on the back of the dash. Also the reliability of the battery to frame.
4) a faulty gauge. Both the tank unit and the instrument can easily be tested with a multimeter.
The voltage regulator will have virtually no effect.
The resistor (light globe) goes on the back of the instrument and will only help by dampening the needle a bit if all else is well . Trial and error to the globe wattage is required.
of course the float could be full of petrol
or the other items you have mentioned - will do some investigation and report back
Adrian
Guys, keen for some assistance here.
I am not getting any readings on my gauge in the console. So far I have checked the float and tested the float on a multimeter. The resistivity does change with movement, So I am assuming the float is ok, also assume the tank is earthed and therefore the float. Couple of questions:-
- How do I test the gauge?
- Does anyone know the cable path back to the gauge?
- Any other checks to help would be great, using a feeler rod at the moment, very agricultural.
Thanks.
Gary Pearce is the oracle on all things 105. Have a look at his post from a couple of years ago
http://www.alfaclubvic.org.au/forum/index.php?topic=1320.msg8199#msg8199
Gully
Pull the 2 wires off the tank unit (in the boot on top of the tank)
One wire is the red light, the other is the fuel gauge needle.
Turn the ignition on, earth out each of the wires in the boot (while disconnected from the tank unit) in turn.
Don't assume the tank is a good earth, try a little wire connected to a good body earth source as your connector.
Look through the back window to the gauge on the console if you can see it and you should see one wire deflects the gauge needle to it's maximum extent and the other will put the light on. Dab the earth wire on and off to see movement.
This test is completely safe at this stage.
Let me know how you get on and I will tell you the rest.
Thanks Gary, appreciate the guidance.
Will give this a shot tonight and see how it responds.
Gary,
Pulled both cables off the lugs and connected them to earth and "bingo" fuel gauge registered full and the backlight came on as well...So I am assuming it is the float device that is causing me the problem.
I have a replacement float, but it appears slightly different, and when I rig it up the gauge seems to be working in reverse??
Yes there is two different brands and (guess what) they work opposite to each other.
You must stick to the matching tank unit.
Next step.
1) Remove your old tank unit from the top of the fuel tank (6 screws)
As you pull it out, observe if there might be any fuel inside the plastic float cylinder. If so pry off the plastic float, and maybe use the one off your other tank unit. It will only FLOAT if it is completely empty.
2) Connect your special earth with to the body of the tank unit and connect your two wires back on the correct way.
3) Turn the key on and move the lever on the tank unit through it's ark, observing the gauge once again.
Be careful with the open fuel tank not to cause a fire.Cover it over with a rag, and in particular make sure all your electrical connections are firmly connected (particularly the earth wire) before you turn the key on.
4) If you don't get the correct response from the tank unit now, the tank unit is faulty.
I can generally pull them apart and resolder them, but I don't know where you are. You might be able to fix it too.
Quote from: Stephen Aarons on April 17, 2008, 10:21:57 PM
This seems like a common thing among older Alfa's, mine does it, and so does my brothers cars. Its almost like a game haha, see how high or low u can get it goin around a corner :D
Mine has always been like this as well. You get used to the needle waving all over the place, and like you guys, I also use mine as a G-meter.
Chris
Gary,
Ended up ordering a brand new sender from Alfaholics. Arrived in 10 days and plugged straight in!
Gauge fully functioning in a matter of minutes.
Based on all the advice, I think I will keep my timber dip stick handy to fine tune the float/levels.
Thanks for your step by step fault finding, great stuff.
Matt