I would try cleaning out the idle air control, the round thing in front of the throttle and under the throttle cover. Just take it off, spray a bunch of throttle body cleaner inside, shake it vigorously, and pour out the black liquid a couple of times.

Make sure that the IAC hoses aren't cracked and leaking air. Also check that the electrical plug isn't corroded. The IAC should humm when you turn the key to position II, before engine start.
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Keeping it running is better than buying new