Started as a prolonged start (worse in cold) until now will not start at all when left overnight but give it a sniff of easy start and away she goes. The van drives reasonably well apart from a slightly rough idle which may or may not be connected unsure at this point.
I believe the crank fault is there because of the prolonged starting as the signal was scoped at sensor and ecu plug and although amplitude a little low (2v positive and 2v negative) seems to respond well to engine speed.

Next thought was an air leak in the filter housing (with priming pump bolted to the bulk head). Capped the inlet and pulled 15 in.hg and the needle did not move after half an hour so think that is tight.

My main query now is what kind of vacuum the cp3 mechanical lift pump should be capable of?? With the gauge in the end of the pump inlet pipe at crank the needle struggled to pass 2in.hg but did eventually reach around 4-5 in.hg max! This seems to low to me but am unaware of the specified value and have not been able to access this information??
Any help would be great or maybe I've missed an important test?? Thank you
This has had a set of glow plugs due to 3 being open circuit