When you are driving and you let off the gas and put it in neutral what is it that stops the rpm's from falling too low? Mine will sometimes catch around 11 rpm and then gradually come down but some times it drops to like 500 rpm and almost dies and once in a while it does die on me. I know it is related to my weird idle problem. So what is it that stops the rpm's from dipping too low?

The amount of air and fuel that enters the motor is what keeps the rpm at a specific level, the ecm has control over that. I dont know what kind of work you had done to the motor but if you had any porting of valve work done and it was'nt done right it could cause problems. It is possible that the motor is'nt in time. Are there any other symptoms? Bad idle? idle up and down? Is the power the same as it was before the turbo spools up?

The isle isnt that bad. It seems like it wants to smooth out but then you hear a slight stutter. Almost like some cams. It strutters about teice a second. I have 430 miles on it so far and I have only got up to 2-3 psi for a short time so far. OOnce I hit 500 miles I am going to run about 6 psi on it. But it sounds fine whne i am driving. And the only head work I had doen was a 3 angle valve job. The machine shp mechanic said that my idle should be fine. He didnt port anything out enough to make it idle bad. Tuesday my car goes into the shop where they did the work to see if they can figure it out.