Ok this may be in the wrong thread and if it is dont shoot me lol. We have a 2001 Automatic Cummins 3500 Dually truck thats been acting up lately. The truck takes FOREVER to warm up to operating temp, but if you let it warm all the way up it runs like a champ everytime. But if you dont let it idle until it completey warms up when you pull out on the road it stays at about 30 mph no matter how hard you mash the go pedal. Once it does this if you pull over and take off again after a few minutes it runs fine all day without a problem. A few people have said it was the fuel pump that primes the big pump in the tank? Im new to the diesel world so my knowledge is very limited on these trucks. Any input is appreciated thanks guys.