My 2000 I30t idles too high sometimes, in all the gears, it doesn't do it on every trip, maybe once every 5 trips. The reason I say "trips" is because when it does have a high idle, it would stay that way for the ENTIRE trip, it doesn't come down even after the engine warms up, but if I shut it off and start it back up after 10 mins or so, it would be normal again, so the high idle trips are pretty random.

Would this be an Idle Air Control Valve (IACV) issue? I am not getting any codes at all. My I still have pretty low miles, all services done up to date.

 

It could be an IACV issue, it doesn't always throw a code. I'd also check the base idle and make sure it's set correctly.

 

Thanks for the comment, every little bit helps.

Wouldn't a high base idle setting give me high idles ALL the time? Since this only happens sometimes, I think something else is causing this. If I lower the base idle, then it would idle too low when it's operating in normal condition (when it's not idling too high), which may end up stalling.

 

My friend with a 96 has the exact same problem. Adjusting the base idle does nothing. We think that it might be a bad engine coolant temp. sensor, bad fast idel cam, or a malfuctioning IACV. You could try to adjust the fast idel cam, but that aint fun.

 

i also have a 2000 i30t. mine idles too low on cold morning start ups. after car warms up its ok then.. probably a sensor. i took it to the stealership and they told me to clean the throttle body, they might as well have just told me to get the hell outta there. i would definitly look into the timing positioning. maybe fuel injector???

 

You could be right about the fast idle cam, I messed with it a few months ago to prevent my I from stalling on cold starts, and now that I think about it, I don't recall any high idles issues before that, but then again, I did adjust the fast idle cam back to the way it was, and it's still happening, maybe I messed it up?

 

Its possible. I would go back and make sure the fast idle cam markings are in the right area during the various engine temps.

Good Luck

 

I had a similar problem with my 01;

I brought it to 2 dealers and neither one could find a problem, since it was a random.

A mechanic at a small gas station found the problem.
the throttle cable was catching on the cruise control cable. I believe he just tightened the cruise control cable and it was fixed.

Doubt its the same problem, but couldn't hurt to check.