accelerator problems

My friend has a 1965 Impala. He says that when he hits the accelerator, it stays accelerated. He says it's the spring. Is that hard to change?

It is incredibly easy to change.
I'm assuming that "the spring" he is refering to is the one that is attached to the throttle linkage and keeps it closed when there is no pressure applied. All you have to do is remove the air cleaner and the spring will be obvious (unless it's missing). If replacing the spring doesn't solve the problem, then it's probably a vacuum leak.

Either way it is a .99 cent repair. Good Luck.