When the tempertures go below 30 degrees outside, my 3.9 will not idle when the engine is cold.

I need to hold the throttle above 1,000 RPMs for 4-5 minutes until the engine will idle by itself.

What do I need to be checking here ?

TIA

 

Do you have any codes?

Have you cleaned the throttle body and IAC lately?

 

Good idea.

I was having issues with idle too, it would get real erratic and sometimes shut off when coming to stop. This is even when hot. I cleaned the TB and IAC. It seemed fine for a month or so, then returned with a vengeance. I replaced the TPS sensor and it's been rock solid ever since.

 

No codes and Yes and No.

I'm sure the IAC need a good cleaning as well..

Is the IAC the only thing that would keep it from idling when cold ?

 

The IAC controls the idle speed. If it's too low you'll stall.

Could be other issues, maybe the PCM isn't going into "open" loop due to a bad temperature sensor. May also be a TPS issue, MAP sensor, etc. How's the battery voltage too? Dakota's are sensitive to low voltage, even if it does start.

 

Clean your battery connections and also get the battery load tested. These trucks need the right amount of volts to run right. I would also clean the throttle body tho too.

 

10-4.

I ordered a new IAC off EBay for $9.50 Shipped. Should be here any day now.

 

1. why ebay

2. why ebay

3. I hope it works...

 

60% less than the same part # here at local stores. Hope to install it in the next couple days. Time..... anyone have some extra to give me ? LOL !

 

Hope it's Mopar. Personally I would have gotten the TPS first.