Transit starting problems

[payway]

Hi everyone, thank you for adding me. I have a Transit 2011 115 T350 LWB. It pulls and runs like a train...however starting is a pain. Lots of cranking over and then fires up, sometimes fires and stalls, and a plume of fumes . I use a garage near to me but being a roofer and not a mechanic I'm not sure I get a great service with them not being a main agent. There are no problem lights on dash and aprt from starting it runs fine.
Any advice would be greatly received, thank you