can you confirm its not the membrane? Try opening the door and poor water onto the outside of the window and check if the seal is keeping the water out.
The nearside front is a very short line just runs to a joint on the bulkhead offside is also quite short. This is from memory from when I replaced mine. I bought premade prebent pipes rather than making the pipes myself.
I have very slowly progressing a similar fault. Tried lots of items new blue sensor new fuel pressure regulator new plugs. Spayed brake cleaner on all the vacuum lines . No improvement by now running low on fuel new fuel problem virtually disappeared still a bit temperamental but loads better I now think the injection nozzles might be a bit clogged as its occasionally cutting out when the revs drop to tick over usually its fine drops to 900rpm but not always but restarts straight away.
