I have a 2004 dakota RC 4x4 SXT with the 3.7 auto. The truck runs good and all honestly yet has a shudder/misfire type feeling to it. I replaced spark plugs and change the air filter with a spectrum drop in filter, Um, Completely cleaned the throttle body and the sensors on it. Had transmission drained and valve body cleaned. Truck has 71,000 miles. Well heres the issue. When driving at a constant speed the rpm gauge will surge up and down constantly about 300-400rpms. It doesnt change the trucks speed at all but if u listen you can hear it slightly reving and your not doing it. Also, where the issue of shuddering/misfiring feeling comes most often is maintaining speed of about 35mph it will randomly shudder or act as if it has a miss to it. Doesnt do this coasting down hill or anything. I have had the truck to the shop and they cant find out anything wrong because it isnt throwing any cods at all. I am at my wits end with this thing and really dont know what this problem could be if you need more info just ask. I need all the help I can get guys. Thanks.

 

i would start with replacing the (tps) throttle position sensor. not just cleaning it, its a cheap and easy fix. common problem on these trucks

 

Honestly, Im going to go tomorrow and get a new tps sensor. 40 bucks... But I really am outa idea's here this could be it whole knows. Because i pulled this sensor off when I cleaned the throttle body and what ever other sensor was on it and clean it not sure what the name of it is. Looked at the tps sensor and really no way of cleaning it must all be electrical so this is a possible culprit. here.

 

I replaced the tps and have yet for it to shudder/misfire feeling to show up on my little drive i went out for. But the rpms still go up and down.

 

Try the tps and what kind of plugs did you put in it?

 

same plugs i have always used in dakota's autolite 3923 platinums.

 

Just checking that they are plugs that the dak likes.

 

well went for another drive and she shuddered again quite a few times. So replacing that didnt do it...

 

i've done everything i can think of, completely cleaned the tb, cleaned the iac valve best i could, replaced the air filter, changed the plugs, reset the pcm. No codes thrown... Really dont know what to do im fed up. The gas mileage sucks im guessing like 11 or 12 max mpg. seems very low to me.. What could be causing this truck it hick up/stutter/misfire/shudder type feeling what ever you wanna call it. The rpm surges alone drives u mad hearing the motor rev while driving...

 

Is there anyone you can take the truck to, to have the fuel pressure read? To me it sounds like a speratic fuel pump, but then again it almost sounds like the problem I am having with my truck, and I am going to have to change the tourqe convertor in mine.