Fuel Sending Float question Please help

[hawkgoalie31]

I have 2 little problems in my 74 duster. First, I have a brand new tank, and sending unit. My gauge is not brand new but re-built. It works when I fill it up it shows all the way full. However when I drive about 100 miles it is on empty and it’s about half a tank plus it goes down really fast. So my question is should I pull the sending unit out and bend the float down? Because that’s what my mopar guy said. Next the duster has the dumb smog stuff but we took it all off. So the vent to on the sending unit I,t we just attached a fuel line with an curl Q anti siphon thing so it can suck in air. But when I fill my gas tank up it always leaks from the top. So should I just make it go up further or is there a better way to do it. One last thing how big is my fuel tank?

Thanks a lot
Brian

 

[169dart4y]

Cap the line and I think you have a 15 gallon tank

 

[hawkgoalie31]

the problem with that is then it will not suck fuel.

 

[demon seed]

Plug the line and go with a vented gas filler cap, if you don't already have one.

 

[hawkgoalie31]

Ok thanks but wat about my other problem

 

[RedFish]

If you have one of the elcheapo senders ( identified by plastic float ) it is likely the problem. We can find out if it is. First thing is to figure out exactly what you are seeing...
There is a difference between empty signal ( 73 ohms ) and no signal ( infinate ohms ).
So when you reach below 1/2 tank does the gauge needle move at all when switch is turned on or does the needle remain at its home/off position ?