I have a 05, Dakota with 4.7 V8. About 2 years ago the battery went dead due to a light being left on (Ask my wife). I charged the battery and then the engine would idle around 700 to 400 rpm, while in drive and completely die while coming to a stop or while stopped, it cranks right back up afterward. Seems to run fine while driving it is only happening while coming to a stop. I took it to a mechanic and they serviced the tranny and had it for 4 days and couldn't figure out the problem. Eventually it went away. I recently replaced the battery and it is doing the same thing again. I don't know if it is the computer needing to be cleared or what but it is starting to get pretty annoying at this point. Any ideas what could cause this. Thanks.

 

First off, welcome the the forum! You can learn a lot here...normally, disconnecting the batter for over a 1/2 hour or so will reset the PCM. Sounds like your idle air control (IAC) is dirty, sticking and it cant relearn the idle. I would start by cleaning the throttebody and removing the IAC and clean it as well. I'm sure others will contribute ideas as well.

 

I agree with above..... AND There are many new vehicals that require multiple restarts and letting rest at idle after a battery install... some cars will even throw a check engine light that when reset with a diagnostic tool clears the issue .. in the future if you have to replace your battery I would have a memory saver plugged into the OBD II port .. although this is no guarentee.. and to be honest not Every car is the same .. even if it is the same make model year and options it may not act the same.. good luck

 

Like was said above,

IAC is more than likely dirty, I pulled the 4.7 out of my dakota and put it into an old wrangler, it idled rough, and would die rolling to a stop with the clutch free. Turned out the IAC was pretty nasty, I pulled the throttle body, and cleaned it with carb cleaner till it was **** and span, reset the battery, and it idles better than it did in the dakota when I bought it.

In the dakota, you could see the tach jumping around at idle, now that it has been cleaned, and the battery reset, it drops down to what the computer is set at and sits there perfectly still. 650

The other thing that has been mentioned is spark plugs, apparently dakotas have an ignition that loves to eat spark plugs like an MDS, people on here are reporting electrodes being non existent at 40-50k.

Clean the IAC/Throttle body, and put some new plugs in it, reset the computer again, and it should run like new!

 

I appreciate the responses. I will let you know how it goes in a few days. Thanks alot for the replies and the welcome..