I've been having low idle at stops and the rmps will go up and down while I'm stopped. Ive tried everything to fix it like new plugs, intake and manifold cleaning and gasket, and a new battery, but I still have the same idle problem. IDK what else to do.

 

Fill up the best gas you can buy and try Italian tune up.

 

When you changed the plugs did you check the carbon build up?

 

Yeah I had the carbon build up cleaned out

 

What's Italian tune-up?

 

At idle, and AC off how are the rpms in park? Do they go up down?

 

The rpms only go down when i am in drive and stopped when I am in park the idle is fine.

 

I think it's normal for the car to do this. Mine does it as well. It has to do with the idle control on the ECU. It takes awhile for it to adjust. Back in the days you could adjust rpms on the throttle? body side.

On hot days you'll probably see it more as there is less oxygen content. I know my car runs terrible at temps above 75F here in Texas heat.

Running the AC adds extra loads, and even then the idle up is not fast enough coming to a stop.

It's too late as of now, but on cold days low temps do you still experience this?

 

You clean the MAF sensor? Grab some MAF cleaner, pull the two screws and hose it down repeatedly.

They get contaminated by the engines PCV when the engine is turned off as the fumes migrate throughout the intake track into the accordion hose and onto the sensor making it not read right.

This is a critical sensor for idle speed and air temperature. I clean mine every 25k mi and mines a freeway car doing very few short trips. More short trips means it needs cleaned more often.

 

BTW, we have a timing chain that is oil lubricated...not a timing belt.

 

Lol - I came back just to say this. If your timing belt breaks on your 2IS, you have more problems than we can solve! Ha!

PS - it has 3 chains. 1 long from head to head to crank, and two shorties that couple intake/exhaust on both heads.

 

ok thank you, I live in socal and its starting to get hot everyday and I started having this problem when the weather warmed up

 

Ok ill have to check that and put in a pcv valve. thank you

 

LMAO I meant to put timing chain.

 

As the air warms up it is less dense (thinner), and that makes a dirty sensor more susceptible to errors reporting the actual flow volume.

Same reason some piston engine prop spinning small planes don't fly in hot weather. It doesn't generate the needed lift (they fly slower) like cooler dense air does.