Hi I am brand new to the Honda world, been mostly a Domestic car owner. I have a 1990 honda accord, it idle's fine when its cold but once its heated up it will idle around 300-400 rpms and the car will shake. If I bring the idle (by using the gas pedal) up to around 600-700 rpms it idles fine. Where do I start, I could see any disconnected hoses for a vacuum leak.