I recently got a '90 Jetta.  When I picked it up it had been sitting in
the snow for a few weeks, but started right up no problem.  Recently,
it will crank and crank and sometimes catch.  Other times, it dies all
the way down and I have to jump or charge it back up.  My daily commute
isn't enough to recuarge it fully, but I've trickle charged it
overnight and after a few days it still eventually quit.  If the car
sits out all day in the cold I have a harder time with it than if I
come back and try to start it after only a few hours.  Any ideas?
Thanks!