Probably could have worked out a clearer title but that pretty much covers it......

.....so basically the low pressure return line from the fuel filter on the 130 TD5 I'm trying to get started today had a break on the little weird connector that goes onto the fuel filter housing. I've ordered some connectors but won't see them till the week so I fashioned something out of some fuel line and sealed it nicely. Ignition on, fuel pump starts whirring and eventually diesel starts ****ing down the side of the fuel tank, but you can see it's coming from the top so clearly I'm going to have to drop the tank but that is a pain in the bum on this one as the tank guard has been put in really weirdly.....so that's a ramp job for in the week.

In the meantime I ran a new fuel line directly from the fuel filter into the tank via the filler neck......now there are no leaks but I cannot get the engine started, I've tried priming and still nothing. I know nothing about the low and high pressure system....could my makeshift return hose be causing an issue?

Painfully close to running again after standing for over a year, so keen to get this roaring today!!

If anyone knows something about this fuel system and can shed some light on this I'd really appreciate it.

Cheers

I can't help with this current issue you have as I have a 300tdi which operates differently.
However, my friend had a similar issue and needed to get to the top of his fuel tank, he worked out where it was from above and cut a hole in the floor for access.
Apparently roadsigns make a great cover and Pitking Products 1/4 Turn Quick Release Self-Eject Fasteners make it easy to get on and off.

The low pressure return goes back to the pump high pressure side, putting the return in the tank will not work, the high pressure side will not be delivering fuel to the fuel pressure regulator and injectors, the high pressure side will just be sucking in masses of air from the LP return connection.
https://images.app.goo.gl/DuiW6Mt4P3mbW1p1A