Non start. Poor running when started (once)

Problem seems to have started after refueling HOWEVER receipt states Diesel and I have attempted to start using seperate diesel supply A check with the filling station did not reveal any other complaints (But then one would expect that wouldnt one ). Also, Customer suggests that it did this breifly a couple of weeks ago but then cleared.

On the one occasion I got it to start it smoked very heavily, ran badly and wouldnt pick up on the throttle BUT the thing that puzzled me was that the smoke was Brown rather than white or black and smelt unusual.

I have fault codes for Glow plugs (which had all failed) but this hadnt seemd to have caused any real problem until the other day (I have replaced one, but the others feel like they will break)

I also have fault codes for MAF but despite swapping for another one it still wouldnt start (With a non running engine I cannot really test MAF using scope)

No other fault codes. It smokes on cranking and sounds as if it is about to start on the once cylinder that has the working glow but wont quite make it!

The thing that is getting me is that there are no real fault codes. I would expect on this (unless anyone tells me otherwise) that any sensor faults would likly generate at least some fault codes. If the pump was knackererd (there were no metel particles in the fuel filter)/excessive leak back then it wouldnt smoke when atempting to start (And I would expect an fuel pressure related fault)

I am not really equipped for a more in-depth analysis of CR diesel systems (My feeling has always been that the sort of high presure side work I could do on CR as a mobile would be really rather limitd) so unless somebody comes up with any viable suggestions I will probabally pass this one on.