Not my day, today

The V6 is now all assembled and finished.
I attempted to start it, and to be fair, it's been stood two months and the battery wouldn't have been well charged.
Initially I turned the key so just the ignition was on.
Observation at this point, although ignition lights were bright, I didn't hear the fuel pump priming any fuel, which I expect it to do?
I tried cranking. The engine cranked at a meduim-low speed. There was obvious good compression. It then made a noise as if it was "backfiring" via the inlet, there was a slightly funny smell. It did this a couple of times, and then the battery "said no", so it was game over, for tonight.
I also observed that the fuel gauge was on red, (MID said 24 miles, don't believe it tho).
I then pulled off the fuel line, from the inlet, and it was bone dry. So, how did it make a "backfire" noise, without any fuel?
I double checked the plug leads, and they are all definately correct. I am also sure that the valve timing is correct (I've done enough of them

). I went around and checked every electrical connector (I know them by heart) and they are all correct.
The battery is on charge, and I've put 12 litres of fuel in a can ready, so I'm hoping, with some fuel and a fully charged battery, she should go?
Thoughts, please - my main thought is why didn't the fuel pump even try, with ignition on? (fuse 18 is intact). Would it give up if there was a low level, and not even make a noise?
Many thanks in advance...