Vehicle: 1998 Dodge Dakota R/T 5.9l V8 (automatic)

Hello. I purchased a Dakota R/T a few months ago. It had a pre existing issue of shifting very hard out of start so I decided to change the trans fluid and the filter. I also used treatment. Since then I've also changed out the speed output sensor.

Now, the issues I'm having are:

- When the truck is cold, or rather when its been off for a while, it'll shift into 1-3, but refuses to shift higher. If I let it run for about 5-10 min, then it'll shift fine.

- If I let the truck sit in park (running), then after 1-2 min, it'll start to slow down and you'll hear the engine chugging really bad. If I step on the throttle/gas, it'll stop but will do it again in 1-2 min. Once it seems to reach a higher temperature, it'll stop doing it and not slow down to a very low RPM like it would normally. It idles at start at around 800.

If anyone could help me with this issue, I'd greatly appreciate it. Thanks!

 

Anyone able to help out here? I changed the air idle control valve but still no change.

I've noticed once the truck get's to temperature, the shifting issue is almost nonexistent.

 

As for your tranny not wanting to shift into OD, but goes thru 1-3... Your tranny when cold will not shift into 4th(OD) until tranny fluid reaches 83 degrees F ... My Dakota does the same thing when cold. It's some sort of tranny safety feature I read about. SOunds like 2nd problem is TPS... Throttle position sensor.. It goes bad and the engine runs like crap right after you start... That's what my DAkota was doing too.
GOod Luck

 

Might want to check temp sending unit,it might be telling the computer to add alot more fuel,