How can I dampen a fuel gauge?

[tpiini]

Hey guys,
All my cars have stock fuel level gauges that move slowly regardless of how much bouncing around you do. The Cobra has a VDO gauge and a VDO sender. As the fuel sloshes around in the tank, the fuel level gauge reacts quickly to the sender movement and bounces all over the place. Is there a way that I can slow the reaction down so that it acts more like a "stock" gauge? It just drives me nuts to watch the gauge needle bounce all over he!! as I cruise down the road.

Thanks,
Tom

[strictlypersonl]

Maybe one of the electronic experts will know whether you can get a choke with high enough impedance...

Alternately, replace the sender with one from here.

[427 S/O]

Tom, I've had that problem since day one!!, I even added weight to the sender arm to where it would barely float, it helped some but still bounces around. A fella told me to get the fuel gauge
module from a mid to late eighties mustang, it unplugs from the back of the instrument cluster and labeled, neg., pos., sender, gauge. I suppose you hook it up accordingly....
I haven't found yet but still on the hunt..

[CobraEd]

I have had exactly the same problem from day one too in my Classic Roadsters car. Annoying as hell. I just live with it. Why didn't they put baffles in the tanks???????????

Ed

[nanard289]

Hi Tom,
Thet are two differents ways to solve your problem:
- a mechanical solution (as experimented by Perry)
- an electronic solution (as indicated here below)
(I don't consider the replacement by an other system as a reel solution to this problem)
About the mechanical solution, you can fix a small shock absorber in the flotting sender inside your fuel tank to hold the float movement or to provide a separated float casing (as a tranquillization chamber) with a very small communication hole (to the tank) to minimize the fuel flow between the float casing and the main tank and consequently, the float movement. However, we have to admet that it is not easy to do it.
Fortunately, the electronic solution is by far more easy (and very cheap): you have to install a small chemical condenser (try first with a 10 microfarad 24V that you can find in the electronic spare part shop) between the fuel gauge sender input (positive side) and the ground (negative side) and observe the result (remove your fuel gauge sender and shake it by hand in medium position) . If there is not significant improvement, try with a 100 microfarad value (alway 24V). The condenser is working like a spring and will absorbe (and restitute) all fast variation signals. Let us know your result. Good luck.
Bernard

[tpiini]

Originally posted by nanard289


Hi Tom,
Thet are two differents ways to solve your problem:
- a mechanical solution (as experimented by Perry)
- an electronic solution (as indicated here below)
(I don't consider the replacement by an other system as a reel solution to this problem)
About the mechanical solution, you can fix a small shock absorber in the flotting sender inside your fuel tank to hold the float movement or to provide a separated float casing (as a tranquillization chamber) with a very small communication hole (to the tank) to minimize the fuel flow between the float casing and the main tank and consequently, the float movement. However, we have to admet that it is not easy to do it.
Fortunately, the electronic solution is by far more easy (and very cheap): you have to install a small chemical condenser (try first with a 10 microfarad 24V that you can find in the electronic spare part shop) between the fuel gauge sender input (positive side) and the ground (negative side) and observe the result (remove your fuel gauge sender and shake it by hand in medium position) . If there is not significant improvement, try with a 100 microfarad value (alway 24V). The condenser is working like a spring and will absorbe (and restitute) all fast variation signals. Let us know your result. Good luck.
Bernard

Now THERE'S the answer I was seeking! It seemed to me that if I placed a small resistor between the lines it would soak up some voltage spike, but I didn't want to do anything without checking with someone a bit smarter than myself. (Not much of a reach to find those folks. ) The thought of completely reengineering my fuel tank/sender didn't appeal to me!

Thank you,

Tom

[jams]

Connecting a Chemical condenser across the positive and negative does not create a short circuit scenario?

[trularin]

DO NOT put a resistor in line with it.

I believe he said put a capacitor across the terminals.

Jams the amount of current the cap will see at "T sub time zero" will not effect the part or the circuit.

I believe the VDO uses 90 ohms, so this may be fine.

Just my $0.02

[ItBites]

Wiping gently with a wet cloth will dampen the gage in question.