ever since ive been screwing with my timing my car has been idling really rough sometimes barely holding on. my vacuum is normally about 18-20 at idle and is now around 15 for some reason with a normal rpm idle(700-800). my timing is at 10-11 degrees right now. i also screwed with my cam timing.the intake cam is advance 1 and the exhaust is retarded 3. could either of these effect my idle that bad? thanks for any help