idle control system

Hi wise ones 😬 I know virtually nothing about cars & engines!!! Be gentle with me please 🤣 My Z3 2.8 2000 (M54TUB28 I think) is cleaning up nicely. Starts & runs. Won’t rev. I’ve changed split hoses. Replaced faulty MAF Started & ran nicely cold but wouldn’t rev when warm. Got the garage to...