Evo 9 idle problems

I have a evo 9 with a new link g4x pnp ecu. i got help with the basemap and got it started. now the issue im facing. the car ramps up to 3000rpm on idle, and runs kinda lean. Around 1.250lambda. and after a minute it starts to ¨jump¨ in the rpms between 2500rpm to 1500rpm. The exhaust also get really hot verry fast, i would guess that has to be the lean lambda?

can anyone help me sort out the idle? as my tuner has no time in the near future to help because of alot of work.

You need to find / fix the manifold air leaks, or close the throttle more. If the throttle is drive-by-wire, it may need calibrating where you need to push the throttle closed against the "limp-home" position spring. 3000 RPM unloaded is about where a "limp home" most would typically run.

Ignition timing is likely low as the ECU tries to reduce RPM. As David mentioned, look for and fix air leaks, make sure the throttle is properly calibrated, reduce idle airflow.

Apart from random leaks Evo 4-9 are also known to have significant air leaks through throttle body seals as they are 20+ years old and never been replaced.

Also idle screw adjustment (counterclockwise turning) in throttle body can be used temporary to combut air leaks through those seals until the new ones will arrive.

will try to check for vaccum leaks etc. can also take a log if i dont find any leaks or weird things

i think i found the issue. the car has a TIBUC bypass als valve, and even when the valve is fully closed it still sucks inn a small amount of air. i would quess this can be adjusted by the idle air screw on the stock TB? to compansate for the small amount of air that goes past the ALS valve?

Maybe. It depends if the amount going past the ALS valve is too much by itself or not, but once you try you'll know.

I wouldn't advise to do that on permanent basis. I would suggest you either fix the leak withe als valve or block it off. Playing with idle screw isn't the way to properly fix the issue but rather the way to get confused. However, as Mike said it could be good tool for confirmation of this particular route cause. You can check your fuel trims- if all of them are positive and have big numbers that's indication of excessive air getting to oxygen sensor.