Sorted the cold starting problem on the 300 tdi auto. On cold mornings it would almost catch, but just not quite, often taking several attempts (8 attempts on Wednesday morning) of several seconds of starting before it would eventually catch, after that it would be fine and start on the button....... until the next morning, the colder it got the worse it was to start.
Spent a lot of time reading about folk with the same problem, here n elsewhere and then wasted a fair bit time and money fixing stuff which wasn't broken, which (of course) made no difference to the problem. Glow plugs, lift pump, leak off pipes, erg blanking, de-cat, earth straps etc. Even tried disconnecting then bridging the engine coolant sensor plug with a resistor, but nothing made any difference.
This thread seemed to make sense (timings out, so advance the pump 2 or 3mm). So we gave it a go yesterday. Except the pump was already advanced as far as it would go, so after some head scratching we decided that the pump must be one tooth out, which perhaps explained why it had been advanced to the limit by someone previously. When we changed the timing belt six months ago we was very pedantic about making sure it was all lined up in the same was the old belt, using pins to lock everything down. Anyway belt off, pump advanced one tooth, belt back on, some more head scratching & jiggery pokery adjusting the pump back to where it was plus about 3mm clock wise.
The transformation was immediate, more power &using less fuel....... and then joy of joys it started first turn of the key this morning. First turn.... astonishing.