[Engine] Misfire and cutting out

[Fig]

Right, my 1.4 petrol van is still giving me issues. I changed the crankshaft position sensor because it wouldn’t start, and while I was under the bonnet I changed the spark plugs and coil pack. But it’s misfiring occasionally, feels like it’s losing a cylinder for a few seconds then it chimes back in. 

Now in all fairness the parts I bought were cheap pattern parts so there’s a possibility they could be faulty straight out of the box, but is there anything else I can take a look at? I’ve checked the fuel pump and filter and they’re fine.

Also, ever since I bought this van it cuts out when you reverse and the dashboard bleeps, but I’ve have a diagnostic kit on it and I can’t find any reason. Any ideas?

[SergioFR]

Any especific error on the diagnostic tool?

It has a fuel pump right? If yes try to do some tests, is just an advice.

[brodfather11]

When it cuts out when reversing does it start right away ? .Or do you have to select a forward gear before it will run?
Any dash lights with the beeping ?

[Fig]

Any especific error on the diagnostic tool?

It has a fuel pump right? If yes try to do some tests, is just an advice.

There’s no errors at all, and the fuel pump works perfectly. I’ve tested it thoroughly, and all the petrol is fresh, I completely drained the tank recently.

[Fig]

When it cuts out when reversing does it start right away ? .Or do you have to select a forward gear before it will run?
Any dash lights with the beeping ?

So I reverse and when I brake at the end of the manoeuvre the engine stops and I get a single warning bleep. No lights showing. And it starts up again first touch of the key. I can’t work it out.