I had exactly the same problem with my old 200 tdi and it turned out to be the alternator. Changed it and hey presto problem gone! Hope this helps

Hi all Can any one help? I need an injection pump casing for my 300 tdi because like a total prat I left a drill bit in the pulley hole, when checking the timing, and turned the engine over. Result, broken pump casing and a heart attack when I checked the prices for a replacement.:( :eek...