Thanks guy's for the info, We're presently just finishing replacing the cyl head on a Vauxhall Vivaro 1.9 CDTI, this gave me the chance to examine the rail, and sure enough this is single point control and has the relief valve and pipe fitted so I'm got some confidence that this may be the problem on the Astra, hopefully we will be getting it back in today and get the rail off.

Keep you informed.

P.S. Mark C have not received any e-mail so far.

Mark Robins.