this has been going on for 1 1/2 yrs now but its really bad this time... i live in phx, az. one hot summer day, the truck decided to studder and hesitate while getting on the freeway/going up hill, and the check engine light came on. it was like that for the rest of the summer, but once the heat laid off my check engine light went off, and the hesitation stopped..?.. okay.. winter was fine no probs.. then this summer same thing. got hot and along with the light came jerky hesitation. even at constant speeds +25 mph. well its winter now n the light is still on n hesitation is keeping me off the freeway, damnit. im thinkin its in the head.. valves or sumthing.. NE BODY HAVE SOLUTION? lol seriously..

i have a completely stock , 1996 dodge ram 1500 with the 3.9 l V-6 , i tried to get it smogged today ( 10/24/2011 ) and it damn near jumped of the dyno . it stutters ( inconveniently ) right at 15 mph it doesn't do it under or over . I really don't know whats wrong but it cost me $50 so far and i don't get a free retest . it passed the "emissions" part of the test and mechanical part but not the visual because the truck kept running weird at 15 mph . i got home and tried to do it again and it did , i hit 15 mph just right , and it jerks and sputters like its catching and then not over n over again . i checked vacuum lines and replaced a few , and it still does it . i don't know whats wrong but it only does it at 15 mph and any help or ideas is greatly appreciated , as of today ( 10/12/2011 ) i have 60 days to get it smogged again . I'm thinking its fuel related maybe more vacuum line needs to be replaced , i don't know , but any and all ideas will be greatly appreciated and possibly even tried . thank you all .

The truck jerks or hesitates while driving at any speed it tends to happen more when I'm using the cruise at highway speeds. It also does it under hard acceleration. It almost feels like the engine is stalling just for a millisecond or like there are two gears binding in the axles. The only noticeable change in anything is that my fuel gauge started to malfunction on me about the same time this started the fuel gauge only reads full when the tank is full after about 30 to 60 miles it starts to read whatever it wants usually it just drops to EMPTY and stays there. I have watch the speedo and the tach when the jerking is going on and i cant see any change in speed or rpm. PLEASE HELP IT IS VERY ANNOYING.