fuel guage not reading full, even with a full tank of gas Options

[smrz914]

Is the float for the sender getting stuck? or is it the wiring. If i go to fill up the gas guage only shows the tank half full. Once i use the first half tank the guage works normally, untill i fill up again.

If I have to take the sender out is there a way to slow down the movement of the needle on the fuel guage? If i'm at a quarter tank and take a sharp right I can get the empty light to come on.

[lapuwali]

On my car ('71), the needle appears to be completely undamped. It jumps around below half-tank over every bump, and reads low in right turns and high in left turns. All are caused by fuel slosh. The sender is on the right hand third of the tank, so a right hand turn sloshes the fuel to the left side of the tank. The problem is worse as the fuel level drops, which makes sense as the fuel level at the sender will change more vertically from side-to-side slosh with less fuel in the tank.

I considered this "normal", as that's what every fuel gauge in every Italian car I've ever owned did, as well. The Italians seem to like undamped meters. I just presumed that's what the Germans did, too.

Perhaps some damping was added to the gauge movement on later gauges, which is why Andy doesn't see it. This is normally done in the gauge, not the sender. A damper slows the movement of the needle so it would only drop on a really long right hander, if so fitted. These dampers are either mechanical, or magnetic.

As for the half-full bit, it's possible the rod the float slides on is bent so the float only goes up halfway. Removing the sender to check this isn't hard. Just remove the expansion tank and the sender is right there on top of the tank. No need to even drain the tank first.