gavinh;124956 wroteNout, it's a Volvo and a manual at that, that might also be an issue in its self (Volvo). Dose it have any service history?
there has been a few ears pricked up over here as it's a manual, hopefully it somthing simples, like swirl flaps or egr valve
To be honest it wasnt a long call and the guy wasnt that knowledgeable about it so I wouldnt expect anything approaching FSH. Any kind of vacuum leak from the turbo or dodgy wiring to a solenoid or a control valve could cause the running issue. Didn't know the engine mounts had vacuum lines running to them so theres that as well. I'm not sure he was getting good advice from his mechanic either.
My feeling is the car won't be available by the time I can get to it. Feel free to have a crack if you're interested.