p38 dse keeps stalling

[jpr.racing]

hi i have a range rover 1998 dse. you can be driving along all is fine but as you lift of the gas pedal the motor just dies and then about two seconds later it jumps back in to live. it also cuts out when try to park. ie going from drive to revs. but then you can start straight away. any body got any ideas what problem might be. thanks jeremy