I'm trying to figure out if the IAC needs to be replaced but in the repair manual it says:

"IDLE AIR CONTROL (IAC) MOTOR—3JL/5JL/5JL
ENGINES
To perform a complete test of the IAC motor and
its circuitry, refer to DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual."

I can't find a PDP manual. Could somebody help me please?

 

What are your symptoms?

 

Here is the post for another thread I started about the problem. This was when I didn't really have a clue what was wrong. The thread title is "Engine won't start cold":


"Hey guys, every time I start my truck when it's cold it immediately stalls out. I have to rev it for a little while or just double foot the gas and break while I drive to get it warmed up. Once it's warm I don't have a problem. I can turn it off then start it and I'm still good. I'm starting work on it tomorrow and was thinking about cleaning the throttle body and checking the Idle Air Control motor first. Any ideas or advice? Thanks!"

 

Yeah, cleaning the throttle body is a first step in figgerin' that one out. Get everything nice and clean, and be sure to leave the battery disconnected while you are playin'. While you have the TB off, test the throttle position sensor as well. They can cause the same problem. In your case though, if you aren't getting any codes, prolly the cleaning will take care of it for you.

 

I'll look at my Snap-On Chrysler manual. I know that the IAC is a stepping motor and some scanners can monitor and display what step it is in, contol opening and closing by steps, etc. Without special equipment, testing may be difficult. Don't know if auto parts stores have a meter that reads this level - but I would check.

 

I already did the cleaning and everything. Those updates are on the other thread. I havn't tested the TBS yet but thats the next thing I'm doing. And thanks gd, that would be awesome.

 

Only way to check IAC is to set stepper and count steps - takes a computer. I would suspect IAC and if cleaning does not correct, I would replace.

 

Thanks for the help guys but I found a youtube video about testing the IAC. Here's the link http://www.youtube.com/watch?v=406BTo4JE3A

 

Do not adjust these IAC's like they show in the video. It will damage the motor. These are stepping motors. Each pulse (5v I think) makes the motor move in or out incrementally based on polarity. The cleaning part is fine. I don't know if the 1 1/8" measurment they referenced is correct for ours either. I have a spare in the garage but it not accessible at this time or I would go measure it to verify.

 

problem's fixed!!! I didn't even bother testing the IAC motor, I just replaced it and it runs like a champ now. thanks for the help guys.