I know of a 1988 Corsica that bogs down after it's been on the freeway
for a while. After awhile it won't go faster than around 40 miles.
Does anyone know the cause of this problem?

The second problem is that sometimes it won't start.  I mean you turn
the key, the lights come on and  everything, but there is no ignition
sound whatsoever.  My mechanic tells me to move the cables of
connected to the battery around a bit.

Any answers?