C-max 1.8 cdtr 2010 starts then conks

Hi,

could anyone help me with what is causing my diesel 1.8cdtr c-max car this issue? Its a 10 plate with approx 91000 miles, the problem I'm having is, as soon as it starts, it conks, we then we need to get this tool with a pump to pull the diesel through where the black bar at the top of the engine is removed, the lad loosens a few things and some sort of pressure valve to do this, I've noticed my car doesn't like rain and has a damp issue underneath, to the point, the floor storage is soaking wet, it looses power in the rain, could water be the cause of this issue coming from a pipe underneath the car? I'm desperate to sort the issue as I'm in and out of hospital all the time and this is causing me so much stress and worry due to my ill health, even a guy who works on ford's and specialises in electrics, is struggling to know why or what could be the cause? I usually have petrol cars and fix what's needed myself but with diesel's, it's all new to me? I might be a female but I've fixed quite a lot of issues on my cars over the years, from new suspension to a cv joint on my BMW.. So I'm not too bad if I know what I'm looking for and have some idea? 

Any help would be very much appreciated, my main worry is the cost now my health has put me out of work, I may not be able to manage to fix the car myself but I can instruct my partner. Thanks in advance guys 🤞🙏