Starts really rough and shakes but after warm calms but still idle fast and slow intermittently.

SOURCE: Rough idle when engine is cold 1997 Explorer V 6

There are 2 common problems on this concern. 1st maybe a dirty MAF sensor. Remove the MAF sensor and clean it with a good electrical cleaner and air dry or light shop air,then reinstall and do a couple of wide open throttle burst to reset it.
2nd problem and we see alot of this is the orings between the upper and lower intake manifold leaks.You would have to remove the upper intake manifold and replace them.

SOURCE: 2000 Focus Zetec-rough idle, very rough under load.

you haven't said if its petrol or diesel so i'm assuming its petrol since your smelling sulfur sounds if you have a misfire causes could be plugs,leads or ign coil i suspect its ign coil these are common to go.

SOURCE: Rough idle and acceleration

I am not a mechanic, so I dont know for sure, but it sounds like a problem I had with my car. It turned out there was a bad wire. We serviced the wires and spark plugs and problem solved.

Dar

• 2007 Answers
• Posted on Jun 03, 2009

SOURCE: it idles fine when cold but when it starts to get warm it idles rough, you can feel it going up and down not badly but i can feel it and see it on the rev counter

Faulty idle air control valve. You could try and clean it with some carb cleaner, or replace it.

SOURCE: 87 Ford F150 idles too fast

either a vacuum leak or an idle air control valve problem most likely.the iac is on the side of the throttle body.cylinder shaped with a small harness.