Greetings everyone. I posted a while back about replacing the shocks on my 96 1500. I'm here to seek advice for a new 'issue'. Basically, when the truck (360ci) is in any gear other than Park or Neutral, it idles fine when the motor is cold. Once it's warmed up and in gear (at a stop-light, etc.) the motor idles significantly lower than I can imagine it should. It doesn't idle rough...just rather low. The plugs, wires, and cap & rotor have just been replaced a week or so ago, and it didn't fix it. I was thinking a dirty/bad IAC valve, but if anyone else has a better opinion, I would love to hear it!

 

How low is low?

 

Educated guess...I'd say 350-400ish RPM. Quite a bit lower than the normal (which I assume to be 650-700rpm)

 

idle speed is controlled mostly by the IAC, with a little interaction with the TPS. when the TPS says you are no longer mashing the gas pedal, the PCM tells the IAC to move in or out to run a slower or faster idle. the PCM measures the result from the crankshaft position sensor.

you did a tune up of plugs, wire, cap, rotor - so that takes care of the ignition system.

next - remove the IAC from the back of the throttle body and clean the pintle and the well it goes into. spray it all out with brake cleaner. poke a wire or small screwdriver through the little hole in the bottom of the well.

don't push, pull, or twist the pintle. you'll break it.

if that doesn't fix it, you can blindly replace it. keep the old one as a spare.

 

Got it...I assume this is pretty easy to do? Pull it off, clean, put it back in and tada?

 

other than being slightly hard to reach, its very easy.
you can remove the air filter or not...
IAC has an electrical connector with a little pinch tab lock.
then 2 #25 torx.

 

great. I'll try this Tuesday or Wedsnesday (dad has Torx in his truck, he needs them tomorrow) and report back. Thanks for the help so far!

 

Disconnect battery ground before you remove it! Also make sure you clean out the port where it goes as well! Good luck!

 

I found it easier to just take the throttle body off and then the IAC. Lets you clean the throttle body too. And you had the means you could make your Throttle Body a 50mm!!!

But I guess you should get your idle fixed before you do any of that

 

Not to mention you can check the plenum gasket.

Here's a DIY for cleaning the IAC. And as stated, remove the negative battery cable first.

https://dodgeforum.com/forum/dodge-r...n-the-iac.html