problem starting and right side amber engine light illumanated

i drove jeep today was fine then went too start after a short while and would not start but engine was turning over, so i disconnected diesel pump at rear arch re-connected and started about ten times no problem so took for a drive and after ten minutes failed to start again? would it be the pump in the arch faulty or is there any way to check it is supplying enough pressure to the main h/p pump on engine or could it be possible there is any other common fault wit a 2005 td4 like this .
kind regards
david.