[84LX89GT]

gtsr515 is correct the inside of the throttle body is coated with teflon which theoretically should never get gunked up with any thing, which of course is BS. I work at a ford dealer and we're instructed to "replace" sticking throttle bodies all the time. They get gunked up right at where the throttle body stops when it idles and as a result is hard to get open again.
A guy that's been my Mentor for the last 2 months cleaned a throttle body with non-chlorinated brake cleaner and used a wire brush to get all the hard gunk out. Now....the throttle body will stick again because the teflon coating actaully does help prevent stuff from building up (although doesn't eliminate it) so after you clean it, you may have to clean it from time to time to make sure stuff doesn't build up (because it's likely to build up faster than it did when it was new and untouched).
But you should be able to clean it out, and if you'd have to replace it anyway, why not at least try to clean it and see what happens before you junk it anyways,
good luck,