MGB--gas gauge gocrazy

[TRIFARI@aol.com]

I have a problem with my 1980 MGB.  The car will only take about $10 wort=
h of
gas before it starts smelling up my garage.  At $10, the gauge shows FULL=
=2E
 It stays there a long while, then goes to half, the drops like a rock to=
 E.
 I realize I probably have a problem with the sending unit and that the
problem will go away if I buy a new one.  I=92m curious, however, if anyo=
ne can
explain WHY this happens.  Thanks for any help.  =