My 2000 with the 4.7 and all time 4WD has been running rough and after driving for 30 minutes or so when on the highway or accelerating my RPM's will pulse my 200-300.

I hope it isn't the fuel filter but I think that would be a more consistent issue but I ran some B12 through a 3/4 filled tank and it didn't see to help.
Air filter is good as well.

Could it be something with the spark plugs, wires, distributors?

 

Or your throttle position sensor could be going out

 

+1 on the TPS also, could be a dirty throttle body or IAC or a combo of both!

I have also seen a bad battery causing low voltage and making the TPS not act right... if i where you i would clean the throttle body, IAC and if that does not help have the battery load tested.

 

+1 (maybe 2?) for the TPS and a good cleaning of the TB

 

All you really have are the spark plugs, no wires or distributors. The 4.7 has coil on plug ignition.

 

That is pretty quick and easy I'll give that shot over the weekend.

Thanks for all the quickt replies!

 

So I don't drive the Durango a lot any more and finally got around to fixing today. Interestingly enough, I was shipped the wrong TPS and didn't realize it until I had the old one out. The old had tons of build up on it so I went ahead and cleaned it off with a dry cloth then a dash of WD-40 and put it back in.
The Durango went from 11.3 MPH to 13.8 and is running better than it has in years.

So, if you have the pulsing issue at all speeds and it runs rough, try cleaning the TPS before replacing it as you may end up with quick and free fix.

 

You should also remove the Throttle Body and clean it as well using 2 cans of throttle body cleaner and an old tooth brush. First remove the Negative batter terminal and cover. When cleaning an IAC do not depress the plunger or damage will occur.

Not sure how you cleaned the TPS.

 

Thanks all.
I cleaned the throttle body, clean the idle air control motor as it was loaded with carbon build up, then changed the TPS and she's running smooth again.

thanks again!

 

Pulse came back after a couple of weeks. I replaced the TPS again and it ran fine for a week then started a ting up again. I replaced the PCM today and it ran like a champ for 5 miles then started pulsing and throwing codes again.

What in the hell is going on with this thing???