As mentioned before, check that thermoplunger wiring.

If you feel you have a fuel issue, they are renowned for injector problems. They suffer water ingress from rear of bonnet which drops moisture on top of injectors. The water then starts to corrode around the top and slightly down the side of the injector...causing it to have too much pressure around it and therefore seizes. The injectors are sometimes impossible to get out, and thousands of pounds went into developing a tool to remove them....which has a 70% success ratio, leaving the 30% needing new engines (cyl heads not available from factory at present)

I say that, but you would deffo have a specific injector fault code if one had failed.

I forgot to mention in my last post that I'm a service advisor at Vauxhall (last 2years) and did 3 years at Renault before that! Haha

Matt