hello, about two weeks ago now, i was driving as per usual, came to a mini round about, stopped, put it into first gear, got up to 3-4k revs absolutely fine, went to go into second and the car completely died on me, ever since this incident, the car cranks, but won’t fully turn, i’ve had it started twice, the first attempt to start again, i just fitted a new fuel filter, primed it with some diesel, it started for a literal second and died again, left it for a few days, started it again, it started mint and ran for a good 5 seconds and died again, i’m clueless, ive been told it could a skipped tooth, but to me it seems like a fueling issue, when i replaced the fuel filter, the feed going to the filter, had barely any fuel in, the feed leaving the filter was full, im stuck with where i’m at with the car and only had it since february this year :/, if anyone has had a similar issue, any suggestions will be help

Lift/remove the right side rear seat squab and peel back carpet to get to top of in-tank fuel pump.

Disconnect the 4-way connector and put multimeter probes into the contacts the thicker two wires go to. Arrange meter so you can see from where you can turn the key to make the engine crank over. See what voltage is shown.