can anyone help me i have a 2001 y reg kia sedona, when the weather started to get cold, it started not running properly. it will not rev up and if it can, then black smoke from unburnt diesel come flowing out the back. it has no power under load, i can only drive at about 15-20 miles per hour unless it changes gear. i have heard it could be a diesel pump, or something to do with the EGR valve and this stops the turbo working. trouble is i have no idea where this is. PLEASE HELP i have no car.