V50 V50 2.4 poor idle and stalling only when hot
After driving for around 10 minutes my 2006 V50 2.4i (B5244S4) will start to idle badly and then progressively get worse until it stalls if I don't hold the throttle on at idle.
I bought the car like this and was hoping to fix it easily. So far it hasn't been easy :(
It had a fuel pressure sensor code so I replaced the sensor and the code went away and the fuel pressure is now normal, but no change to the idle/stalling issue.
The PCV hose from the engine cover to the oil filter housing was broken in several places. Replaced it, no change.
It happens like clockwork, as soon as the coolant temperature gets up to ~90 degrees the problem happens and stays until the engine cools after being turned off for a reasonable amount of time. If it stalls it will restart fine and then resume the bad idle/stalling almost straight away. It drives fine when it's not idling.
I've tried heating components (throttle body, MAF, ECU and any sensors that are easily accessible) with a heat gun and trying a cold start but so far I haven't found anything. I suspected EVAP valve as I read that opens only when the car is warmed up but I disconnected it and there was no change. It is like something is switching on when the car is warm (and a second or two after restarting) that is causing this.
Has anyone had this problem or know of some system that could cause this only when warmed up or any diagnostic methods I could use?
NB. I am using a generic code reader but have ordered a DICE from China but it won't be here for a while. I've also posted this on some S40/V50 specific pages elsewhere but haven't had any success so far.