Turn your ac on.LOL
I bought this H3 in November. Ac didn't work but it had bad idle until last week, I charged the AC system and now it idles great.
Now I'm cool and idling perfect..lol

 

Band Aid covering a symptom. Have you read this thread? Acts like it wants to stall/rough idle -No CEL -What To Do:

 

In the 4 months I have owned it,I have done nearly everyone of them.First was a full tuneup. Then since the radiator went bad,New Radiator and full engine tranny flush with new filter and fluids. Gas cap change.Running different grade gas looking for any edge?
You say this is a band aid..my question...why would the ac make it idle perfectly?What is being triggered to with the ac on for it to have absolutely perfect idle? That answer will probably be the one I need to fix the idle when the ac isnt't on.dontcha think?
So,that being said,any mechanic gurus have an answer other than tossing out typical tuneup/old age issue answers like clean this..clean that..change this..change that.
I am not trying to be an ***, But lets see if anyone can answer this weird anomaly.
I am good with it right now because it is hot in Alabama and going to get hotter so the AC will be on a lot.

 

RPMs go up a bit when AC on typically - enough to smooth idle

 

Not really. it ildes nearly same rpm. if that was the issue.it would have idled when I eased into it slightly with ac off. I tried that. Don't work.

 

Ain't rocket science, it puts a load on the motor which is responded to by a minute bump in fuel/spark/rpm which when looking at the Tach appears like the same rpm because it is offset by the AC load. Remove the load (turn off the AC) and the fuel/spark/rpm are adjusted as the extra work is no longer required to offset the load.

I5s vibrate because they are not internally balanced motors.

 

so there is no cure except to keep the ac on for load on the engine? Then that is not a band aid.this is the fix.
When ac is off, you can sit at red light with it revving 1500 and it would choke itself nearly off. Some days..might not. It was a hit and miss deal
I have owned cars that idle funny because of their designs..Chrysler conquest with balance shafts are funky but could always get them to idle fine when you fixed the issues.

 

The problem is what you think is a bad idle, may be normal, may not be.

I gave you the link to the Acts like it wants to stall/rough idle -No CEL -What To Do: thread and you said you "did nearly every one of them." When you have done the full list.... ALL of it..., let us know because that is what you do to make sure an I5 is running as smooth as it can.

 

Every one except camshaft actuator solenoid.
So you think that 1 item is the issue and only when there is no load? I doubt it.
Like I said..if any real mechanic with real mechanic background has ever encountered this..hit me up.
I can take pot shots at it on my own with my own knowledge of cars

 

How does your H3 run now, if you turn OFF the A/C?