Mazda FS-ZE engine idle issue

Hello all, first time posting.

Background. I just bought a Ford laser RS with a swapped JDM Mazda Fs-ze & custom standalone ECU imported from Japan. Loving the power since where I'm located most cars are sub 150hp due to taxes.

Anyway, my issue. Sometimes when starting the engine it will idle at less than 500 rpm, turning on the A/C will lower it more. It cuts out also when putting into gear. However, when this happens, I turn off the A/C and drive it with low rpm until I past the corner and redline it once and then the issue goes away instantly... Very strange. This is not a sustainable strategy for me since I live in a quiet community, so redlining it will get me some maddog stares. Has anyone had a familiar issue before? Any fixes possible?

Many thanks in advance. Also, any idea what this Japanese text says?
20230725_113037.jpg
 
It says "Please replace timing belt every 10000 km.
The odometer reads ________ km (at last change)"
I hope it's not every 10,000 kilometers. That would be extreme! :D

My JDM engine has the same sticker.
 
Back