Interesting Idle Issue, try to diagnos Options

[Mstoochn]

to put it simply, the engine shakes a fair bit during idle, but stops in gear.

This post has been edited by Mstoochn: Sep 16, 2009 - 12:58 PM

[Jamchell]

Does the check engine light come on at anytime when its acting up?

Is the idle rpm very low(<500) when its "shaking" ?

You could try shorting each spark plug wire to ground and seeing if one of the cylinders causes little or no change when shorted. Be careful not to run it for long with the wires disconnected if you choose that route(I recommend grounding them), and watch that high voltage so you don't get shocked.

It could be a fuel injector or some other electronic item. Works fine when uniformly cold or hot, but one of the components in it shrinks faster while cooling than others and causes an intermittent open circuit.

Might also be worth checking your fuel pressure when its idling rough, if you had an emission gas analyzer you could check for a lean or rich misfire very easily. There are a few things that could cause this actually.