I recently had a timing belt break (and wrap madly around the crankshaft). I should have changed the timing belt, I know now in hindsight, but it did make it 180K miles. I got a used 2003 2.7 with 118K on it and DID change the timing belt, water pump, etc. I also had to change the fuel rails and the plenum due to a few changes. The car fired RIGHT UP first time...but shortly afterward (after test driving it the first time) it developed an idle problem. Instead of idling at 900 rpm, it jumps to 1200...then up to about 2000...then back down to 1200, then back up to 2000. I just need to know which component is the most likely culprit. Any suggestions would be great.