Bad idle

So here is the story, one night I was driving down a hill kind of fast and did not know that there was train tracks at the bottom and I hit them fast and hard and it bounced my truck pretty bad, right after the tracks it shut off and I had to pull over and it had a hard time starting right back up. After it started it had a bad idle. It fluctuates between 400 and 1000 rpm's, but does not fluctuate at all while driving only at idle. I have replaced my air idle control valve, all my vacuum lines, and also my spark plugs and spark plug wires. I am still in high school and work part time so I do not have enough money to keep throwing at it. If anyone has any idea what it could be I would really appreciate the help!