for most car is normal,...not normal for me,if press to 1200rpm,no vibrate.oledi change spark plug.
shud be same with or without a/c if engine is healthy...air cond pun reach til 1k rpm max.
mine with air cond on, rpm naik sikit, 100-200rpm.shud be same with or without a/c if engine is healthy...
wats ur idling rpm??? r u on stock cam??? - - idling more than 800rpm??
check ur vacuum hoses...n distributor rotor..