hey just wondering if any one has had this problem, my mums car it is just to get that out the way, when she starts it cold it idles fine and its fine on take off and slowing down but once its at temp it get this idle that it shakes the car and it drops about 200 -400rpm and it keeps doing this its been to ultra tune and also ford and they both know how to charge but have to say ford said that they had it on the computer and it was showing nothing in codes and all they could come up with was it could be the computer or the wiring somewhere is breaking down, (oh please wire only lasts 15yrs why my eb is fine) so i was going to try the computer out of my eb but its an EL as the EF runs coil packs and not the dizzy, so i am not going to go to the Wreckers and pull one for a check only.
but you put your foot down to go again and the miss is gone again. it has brough her car to a complete stop and needed a tow and the next day it starts. its annoying not liking seeing the ford on the towtruck.

any help or ideas or process of elimination would be great. thanks