1996 528 engine dies when warms up !

Hello, Hope somebody out there has some ideas-possibly from previous experience (with the appropriate cure!)
The car starts fine when cold and runs beautifuly quiet and smooth until the coolant temperature needle rises out of the blue zone when .... it suddenly dies- usually with an asthmatic wheezing sound from the intake manifold/throttle area. Also immediately at this point, the fuel pump kicks in as if fuel pressure had dropped, and the idle control valve can be heard buzzing away.

The idle control valves internal valve is clean and moves freely, possibly too freely as it wobbles back and forth with very little effort instead of being firmly shut by spring pressure like the one in my Volvo 940. Is this correct? or could the return spring be broken? There is fuel pressure in the injector rail when I open the end valve, but is it enough? What else are common problems/weak points ?
Fuel pump, fuel pump relay, Engine Management Computer Relays, Sensors-which? fuel regulator,
Thanks to all in anticipation, any thoughts at all would be greatly appreciated before I fork out to have the OBD scanned at a garage, if I could get it there!

In this case its probably not the ICV.

does it die when you dip the clutch when driving? or does it die on idle? if it dies when dipping the clutch, for example, when approaching a junction, then at a guess i would say the camshaft position sensor. They can work one minute then stop working the next. Then go to start it and all seems well. Unfortunately, the only way to be totally sure is to get the fault codes read.

Hi, Thanks for reply, It first started cutting out when driving along a straight road, or approaching a junction, or as now- sitting idling and warming up in my driveway. it seems a temperature related thing as the several times I have since tried it it fairly consistantly dies when the temperature needle leaves the blue zone. It is an automatic by the way. Sometimes it will restart afterwards by opening the throttle wide but then runs roughly. Cheers, Dave.