HPFP how it works?

[Pesky jones]

Hello everyone. Does anyone know how the fuel pump works? Specifically the one with the banjo bolt. I mean - why the two fuel line etc.

The reason I'm asking is because every now and again, when starting up the engine after a perioud of ten hours or so it stutters momentairily before turning on. This has been happening since I changed the cam follower in the pump. I also changed the pcv so could be that but reckon it's the cam follower.

 I've got it in my head that it's because the banjo bolt has been screwed in such a way that the hole in the bolt (you'll know it if you've seen it) isn't aligned properly to let the fuel run smoothly. But then again it still accelerates and drives as it did before - Don't know whether this means it can't be the fuel line or what 

[pudding]

Banjos don't require any alignment.  Fuel flows out of the hole in the bolt, around the 'banjo' fitting and back into the line.  You can't misalign them.  Brakes use the same fitting.

As for how the HPFP works, low pressure fuel in, compressed mechanically, high pressure fuel out, simples!

[Pesky jones]

Cheers ok fair enough so it's not that then. Perhaps its my battery. Just seems a bit of a coincidence since Its been happening since I changed my pcv and cam follower.

[rich83]

Mines the same. The first start is always crap.

[Dan_FR]

Nothing to do with the Banjo - It's a common thing with these engines. Its a mechanical fuel pump that needs to rotate in order to build enough pressure for fuel injection. Try holding the key on the starter a little longer until it properly fires in to life, rather than just the first fire/hiccup

[Pesky jones]

Cheers guys puts my mind at rest. I was just a little concerned that I don't seem to remember it doing it before I changed cam follower and pcv. But that could be because of only had the car about a month before hand and hadnt noticed it.