Hi ALL, I asked the above Question .
   I changed  the two fuel filters ! still the same 
   I changed the fuel pressure valve ! still the same
   I change the pressure sensing valve on the fuel rail !
   still the same.
   I TOOK THE INJECTORS OUT AND FOUND THREE TO 
   BE LEAKING CHANGED ALL FOUR ."PROBLEM NOW 
   SOLVED"
                
 Bob Lamb
                
 July 2010