I have a 99 Ram 1500 with the 5.9L. Sometimes after running awhile, when I let the truck sit for about 20-30 minutes, it idles rough then runs rough after I put it in gear. It has a hesitation at first, then runs ok after I drive a hundred feet or so. Kinda weird. Any help?

 

Maybe try some injector cleaner.

 

Clean out your idle speed motor/control/whatever you wanna call it....the IAC...it's on the side of your throttle body. Also check your coolant temperature sensor. They're the two sensors that regulate idle once the truck is warmed up.