Hey guys, I'm having a rough time trying to figure out why my 02 dakota 4.7 4x4 is stalling out when the engine is cold. It only does it when I come to a stop, the rpm's drop and sometimes it can catch itself and go back to normal. The strange part is that the idle is rock solid after driving a stopping for a couple miles. I have tried everything I could think of so far. I swapped out the map sensor, tps, iac, and even seafoamed it. I looked through as many of these threads as i could and couldn't find an answer, so if anyone has any ideas I would really appreciate it!

 

When did you last clean the throttle body?

I mean by hand, not pouring something into it. The passages can get pretty messed up with carbon.

 

I pulled it last week and did a full hand cleaning until it was spotless. I also cleaned up the iac.

 

Good.

What are the RPM's doing?

Any codes showing? How are the plugs?

 

The rpms drop from 500 with the ac off (750 with the ac on) to 200 or lower and sometimes stalls out when I come to a stop. There are no codes and the plugs were recently changed also.

 

It's odd that it just does it cold. Mine will do it if the throttle body isn't cleaned regularly.

Check for a vacuum leak. Make sure all lines are tight.

Here's one, do you notice it idling better or worse with your foot on the brake? Maybe a bad power booster is causing the a/f to go lean.

With the a/c on, will it still stall?

 

Ok I'll have to go check all my vacuum lines tomorrow. Yeah I noticed that if I push the break even in park my rpms will drop some. It also does it when I shift gear to reverse and yes it still stalls with the ac on. Thanks for all your help! I'll get back to you about the vacuum lines asap.

 

I agree. Sounds like a vacuum leak. Did you get it spotless? Did you get the IAC port as well? Might just be a bad IAC.

 

Yeah I cleaned the entire thing until it was spotless. The iac is only a few months old, I replaced it when I started trying to fix the idle problem. I'll check all my vacuum lines tomorrow though thanks.

 

Low tranny fluid will cause the TQ to stay in lock up mode and die at low rpm.