How does the fuel sender or gauge work to introduce the "delay" so that the needle on the gauge does not bounce all around with fuel sloshing in the tank? Is there a capacitor in the fuel sender unit?

When i replaced the pump i had a new ground wire tack welded to the tube and and wondering if maybe the heat damaged a capacitor or something because now my gauge varies up to or more than a 1/4 tank with braking/hills etc.

thanks.

 

Usually there is an ANTI SLOSH
module behind the dash.
I never opened one but caps would do the job.

 

Nothing that sophisticated in these cars, it's a function of the gauge movement itself.

 

Yeah, that's all i could find in the wiring diagrams too. Do you think the gauge could be messed up? The funny thing is that it works fine, just too much fluctuation. I would think if the gauge were messed up it wouldn't read at all or it would peg or something????

 

It sounds pretty normal to me, I wouldn't even worry about it.

 

Or if you’re the engineering type
you can throw a couple of caps
across the gauge.

 

If anything the sender unit may have been exposed to rough treatment, either mechanically or electrical. It consists of nothing more than a resistance wire wound around a small thin fiber board where a wiper is attached to a rod and a float. The windings may misplace themselves along the fiber board, or the rod or float positions in the tank may have been altered.
Like Apeiron says there are no caps anywhere, the delay is in the working principles of the gauges themselves. A cap wouldn't help the uphill/ downhill difference, only float position inside the tank affects that, and it's a quite common phenomenon.
If the guage doesn't "descend" linearly then I'd suspect resistance winding displacement in the sender unit.

 

I know i have heard some say that there gauges use more in a certain range but ours has always been quite linear......approx 100miles/ quarter tank. It is just this waviness of the needle now.

I was doing some reading last night and apparently some senders of this style have a mechanical friction brake to slow response. Do ours have something like that? I din't think so when it was out as the arm moves very easy with basically no resistance, but i thought i would ask.

 

Ok, just verify/ check that the float is positioned exactly in the center of the tank like i guess it was originally. If it for some reason has been positioned more towards one side of the tank then waviness would follow.

 

The sending unit only goes in one way and the float arm/resister is welded to the tubes, so it is always positioned the same way.

 

i have the same thing but it says its full all the time what should i look for[

 

i have the same thing but it says its full all the time what should i look for[