Hi, i have a problem with my fiat and cannot work out what is wrong , so can anyone HELP!!!! . My fiat runs fine in the dry but as soon as it rains it starts to judder, you put your foot on the accelerator and it struggles to go up the rev range, when you go along the more you put your foot on the accelerator it slows down WHY?? also if its raining and you pull up to the traffic lights it konks out. any ideas would be great. THANKS