I just had the major 105,000 tune up on this truck. They replaced the timing belt and a bunch of other work was done in acordance with the factory. Now, when i depress the clutch, the idle races to 2000 rpm, then back down to 1500 rpm and then again up to 2000. It repeats this evertime i push the clutch, or barely tap the gas when parked. Any idea why it is doing this? I am going to take it back to my mechanic, but i would love to have an idea of the problem, so that I can bring it up as a possibility.