Ok, fitted the newer breather pot, no change, blanking the hose from the inlet tract to breather helped a lot with the idle speed with the ICSV connected, but the revs still hunt consistently with it connected.
I set the CO pot to give me lambda 1 when the car was hot and iSCV connected, revs around 1200 , can’t see any leaks, used leak spray etc.
I have noticed tho that if I rev the car, the AFR immediately goes lean, like 1.16 lambda, that’s worrying I thought, but maybe it’s the response time as I’m statically revving it and it’s not under load. I.e the engine can rev freely and the ÉCU can’t compensate that fast unless it’s driving conditions.
Impretty much at a loss now.
Rich