X2 on either the FPR or IAC.

IAC circuits/valves can be seen on forums for many different vehicles as causing the symptoms you're experiencing, and the FPR has been the cause of such symptoms on many a VX.

I would have suggested that the drivers' side floor mat was getting pushed up against the gas pedal, but that usually just creates a high idle, and wouldn't explain why the engine is stopping after a few seconds.