It only happens within the first few minutes of starting it. Idle will surge from 1500 and drop down to below 600. It actually stalled itself yesterday. Forgive my ignorace, but a lot was done to the car before I bought it, including a cam, and I am not certain which cam it has.After a few minutes, it resumes normal cammed idle of a steady vibration at roughly 800 rpm. My initial guess is that the computer is not calibrated to the new cam, or that I need to do an idle reset. Ideas??