1.6d fuel issues :(

[wee bugger]

Couple of weeks ago, had an issue where the van wouldn't start. New fuel tank fitted a few weeks before, and van had been running fine, used most days and was ok the previous day to failing...until the day I was taking to get its MOT!!!

had a mate/mechanic/t25 owner come round and looked like the diesel filter had failed and was somehow letting air in. Didn't have access to a replacement and he temporarily put in an inline filter in place, and eventually got fuel to pump and van back up and running. a couple of days later its starts first time, taken to MOT station (passed) and running wise back to normal. Was away on holiday (not in van) last week, and this morning jump into van and no starting

Check engine and no fuel in the pipe between filter and pump (again). so
1. took pipe off pump, sucked through diesel (doesn't taste too bad) and
2. clamped fuel pipe before filter and fuel does not "run back".
3. Connect pipe back to pump
4. release clamp
5...fuel immediately runs back

Up until this happened 2 weeks ago, never had any issues with fuel and the van would often sit for weeks unused, and was fine for first 2 weeks after tank replaced.

Anyone got any ideas/experience of what to check next?

Starting to get a bit stressed as just spent a fortune on suspension/welding etc to MOT

[muttleypup]

Check/replace all the fuel line from the tank through to the pump as it have gone porous. give them a good squeeze all way along, any damp/wet a sure sign they're letting air in. Easy and cheap enough to replace and use proper fuel line clips not jubilee. If it still persists then pump may have a worn seal, a temp fix is to add a one way valve in the fuel line just before the pump, the close the better (or get a primer bulb which has the valve in it too), again cheap and easy to do and more than likely run for ages with this setup.

[wee bugger]

Update, the pump has been checked (pressure tested?) and it's working fine. The mechanic thought maybe the tank somehow was creating a vacuum, but all vents etc checked and all appear to be doing as they are designed to. All pipes checked too, and nothing appears to be amiss (most replaced when new tank fitted a few weeks ago).

One way valve has been fitted and seems to be sorted (for now)...away in it for the weekend, so fingers crossed

[muttleypup]

Well at least it's sorted for now but air is obviously getting in somewhere allowing fuel to drain back, all very well mechanic saying that it all works as it should but clearly it isn't ! Something to investigate after a good weekend away when you can take out the one way valve.