110 fueling issues

[mattsccm]

My 110 has started cutting out, mostly, at the bottom of long hills. Its fine on the up and almost always on the flats. Seems to be happening with no throttle.
It is a D plate 110 that started life as a 2.5 petrol but was converted to a 2.8 Isuzu diesel. That was a good 8 years ago and no problems until this year. Fuel gauge show about half to 5/8 full currently and it was about that last time the problem occurred. It is about right as 40 quid filled the tank to the brim. Once full it ran until the fuel dropped to this level and I went down a very long, braked hill.
Could the slope be putting the fuel uptake into thin air? That though wouldn't let it start again, with a bit of throttle, relatively swiftly.
No idea here.

[stable]

When was your fuel filter last changed?
Goosed lift pump?
Hole in fuel line sucking air in?

[mattsccm]

Filter new as part of solving the problem first time. No idea about pump or how to check and as for the pipe, no leaks but obviously no idea what's going on inside the tank.

[mattsccm]

Its done it again.
Didn't top it up quite soon enough.
I primed the filter again and bobs your uncle.
Now this has me wondering. Every time this happens I add fuel. Of course I open the tank. Could I have a vacuum being created?
This time I just opened and closed the fuel cap before priming the pump.
I suppose the thing is to drive it with a perforated cap for a while.
I have come across this on a motorcycle when the breather pipe get blocked so that got me wondering.
Does the fuel get taken in from the bottom of the sender unit and could the lowest level be blocked?
Hmm

[dpcwright]

I have had this happen to me on my 90 with the tank all most half full it would cut out and I traced it to an air leak in the fuel line. I would suggest you take the fuel pick up pipe out of the tank - remake the joint then carefully check every inch of the fuel line - and if it is still in, bypass the sediment filter.