So I got it back to the shed, replaced both fuel filters and cleaned out the glass bowl, and took the top off the injection pump to check the metering valve wasn't gummed up. All seemed good - filters looked fairly clean, gauze at injection pump inlet was clear, inside the pump was reasonably clean but in particular the metering valve was not gummed up and rotated freely in its housing. I gave it a polish with some 800 grit wet and dry anyway, but I'm fairly certain it's working as it should.
It was a pain to bleed through after changing the filters, but the lift pump was definitely doing something and I got as far as getting fuel to the injection pump - though there wasn't much of a spurt from the injection pump bleed screws on cranking.
Anyway, another few squirts of brake cleaner got it going, and it happily idled for an hour or so - but then after about 45 minutes of use it cut out again, identical symptoms to before.
Since then I have replaced the lift pump but not yet tested it other than leaving it idling for a while, and checking it starts again after being stopped (which it does, pretty much on the button).
So my question - do these symptoms (suddenly just stopping, then not restarting without some solvent to get the revs up) suggest it could have been the lift pump all along? It didn't splutter or run on one or two cylinders at all, just cut out like the stop lever was pulled, which made me think it was more likely something in the injection pump sticking when it was warm.
As a side note, I flushed out the tank a year or so ago, and cleaned the gauze filter on the fuel cock, so I'd be surprised if that is blocked. Fuel seemed to be flowing reasonably well from the tank when I changed the lift pump.
I'd be grateful for any comments on this as it's doing my head in!! Many thanks for reading this far







