Hey guys.
Any suggestions would be helpful.

I have a 2006 Dakota Quad cab, 2 wheel drive, with the 4.7 engine.

I have owned this truck for many years although I did not buy it new.

For what seems like years, it has been idling strangely.
The idle will rise and then fall.
Never enough to die. Usually between 700 rpm's to 1800 rpm's.
Some days it wouldn't do that at all.
Other days it would be very bad.
I had gotten use to it.

Now I have a new issue and I feel the two might be related.

For the past 4 days it has not been shifting very well.
Meaning, that while I am slowing down to a stop, the transmission will shift to a lower gear prematurely.
Imagine if you grabbed the shifter and moved it to 1st gear while doing 35 mph.
It feel like I hit the brakes and the truck jams down in speed with a big thud.

And it seems that while accelerating, the truck shifts normally.
Although, not a smooth as it did years ago.
But smooth.
As soon as I let off of the gas peddle, the transmission will shift out of over-drive.
Like, as long as I am on the peddle, the gear can be held.
No peddle - it drops down to the next gear and as I slow down even more, it continues grabbing new lower gears - but too early.

When I noticed the shifting issue I also noticed that the idling issue became more severe.
The idle will drop down to 500 rpm's or even lower at times while I am sitting at a light.
Makes me think it is going to die.


I suspect a vacuum leak.

Does the transmission shift using vacuum?
Because I have always thought that my idling issue was due to a vacuum leak of some sort.
It was just never severe enough for me to react to it and figure it out.
I am not familiar with these transmissions.

Any thoughts?
I am planning on digging into it this weekend.

 

what you need to do is replace your throttle positioning sensor, about 105.00 at dealership, never buy aftermarket. this will solve all your issues. bolts right into throttle body, about 2 minutes to swap out. your truck may still do the same idle issues for a bit, but once it settles down, will idle normal and shift properly

 

This


Disconnect the battery for while to wipe the adaptives also.

 

Thank you guys!
I'll be all over it this weekend!

 

I'd be tempted to replace the IAC and clean the TB while you are at it.

 

I'm headed to the dealership right now.
Hopefully they have one on hand.

 

Agree with all the above. New TPS and IAC, clean throttle body, and I went the extra step and changed my spark plugs. I disconnected the battery before starting the work and even turned the key with the battery disconnected. Once job was completed, went for a run on the interstate. Most of my driving is city and before I had the stumbling at stop signs and poor MPG.
Now it runs much better and my mpg is back up to where it was when I bought her new.

 

So here's the nuts and bolts of it all.

I changed the TPS unit.
Took 15 minutes.

I didn't go the extra steps.
Weather is nasty and I was anxious to see if the TPS unit was going to help my issues on its own.

IT DID!
No more varying idling.
No more crazy shifts.
Actually runs and drives better than it has in years.

A big thank you to the ones who commented.

😎

 

Sorry, no sympathy here. My weekend weather was -20 C (-4F), I see that you are mid-50s today . . .

 

I've been running with an aftermarket TPS for the past 7 years. I didn't get the memo.

I think I kept the original since there was no difference when I changed mine - was trying to smooth the idle out back then. did all the "extra steps" also. May put it back on.