04 Dakota SXT 3.7L V6.

I have been trying to eliminate problems one by one, hopefully I will be able to use this truck for what I got it for: moving my kid into college, and a trip out west and back without getting stuck on a highway somewhere in between!!!

Around 30-40 MPH this truck starts bucking and misfiring. Hit the gas and seems to go away. ONLY happens when foot is barely on pedal, trying to maintain constant speed. Again, very little gas being applied to keep at this speed. Dont know WTF is causing the bucking. PLEASE guys if you have any ideas. Im about to leap iff the nearest bridge. OK maybe not but this sh** is really aggravating. Have done much recent maintenance work including plugs, coils, TPS, IAC, clean TB, etc etc. Have cleaned injectors. Really need a pro to advise me. Next step would be getting hosed by dealer for $1000 to diagnose this sh**. Another non related problem is the "jumpy" idle. Its at 800 for a while then drops, then struggles to get back up to 800....BUT FIRST need to figure out why its bucking, etc at speed.


Also just a shout out to the guys that helped me with other stuff on here. I really appreciate you getting back to me with all my stupid questions. You know who you are. THANK YOU.

 

Does the bucking feel engine or transmission based? Could be the transmission hunting for a gear or the engine picking up and losing spark.

Any codes come up?

Did you replace any sensors, or just clean them?

Having an erractic/weak idle and issues at minimum throttle, I have to wonder what the fuel trims look like, as well as the IAC motor response.

 

It feels engine related. The sensors have been replaced. TPS, IAC. No codes, which is really frustrating.

 

You may be surprised how much a good shop can find out with a good technician and a few diagnostic tools.