Low Idle.

[Windowsrookie]

My Comanche has a low idle, and nobody has been able to help. The TPS is adjusted correctly, and the Intake manifold bolts are tight, yet it still idles at slightly below the first line on the Tachometer (almost stalling out). Anybody have any idea what the problem could be?

[BLHTAZ]

Have you removed the IAC and VERY thoroughly cleaned it and the throttle body? If it is carboned up and clogged, it typically causes a high idle, but if it's bad enough it could restrict air flow and cause it to be low.

 

There is nothing clogging or blocking your primary air intake through the air filter is there?

 

Are all vacuum lines in place and clear?

[wallisek]

How is your battery / alternator? I know this is common on newer model jeeps that have a dying battery / alternator. Runs fine when you apply throttle but at idle it barely runs. With a bad battery or alternator it may not be putting out enough juice and making the sensors / ECM go nuts. I had this happen twice on both of my jeeps , each time it was a bad battery.

[BLHTAZ]

How is your battery / alternator? I know this is common on newer model jeeps that have a dying battery / alternator. Runs fine when you apply throttle but at idle it barely runs. With a bad battery or alternator it may not be putting out enough juice and making the sensors / ECM go nuts. I had this happen twice on both of my jeeps , each time it was a bad battery.

I just had the same problem on my 2002 Ram, but I don't know if it would affect these trucks like that.

[Windowsrookie]

I cleaned the IAC, and the volt gauge reads at a little above 14 at Idle (unless I turn on the lights, then it drops down to a little under 14 volts). All my battery cables are new too. My battery looks to be older, but I haven't had any issues starting the truck with it (even in the cold weather here).

 

All of the vacuum lines appear to be in place, the Air box lid does have a small hole in it. I plan on picking up a new lid as soon as one shows up in the junk yard.