HELP ME ANYONE that knows more than me about the dreaded n43

[Stychlee]

Hello again my saviors in the last Fortnite.. have to thank I am the reverend again for taking the time twice to answer my questions as I was doing the head gasket on my son's 318 n43. Been retired from mechanics for over 15 years and after that long you lose a bit of the confidence you had previously and as well as that I haven't worked on this engine before and so many parts of the set up and how they work has changed..
Anyway I have just finished the head today and other than the thin vacuum pipe that starts under the inlet manifold and I could be wrong but it looks like it is meant to fix to the vacuum pump (think that is that) but I can't see anywhere it could push onto.thete is a right size nipple on the sensor (maf I think) on the air intake but that looks too far away unless I routed it the wrong way when fitting the inlet back on.the problem is the engine ticks over perfect but when I rev it, it sounds like it's hesitating similar to fuel starvation..as well as that the brake pedal is rock solid and I have looked at the large diameter vacuum pipe going from the unit at the back of the camshaft which I presume is a pump and it all seems ok..
It's probably not worth mentioning but I had lost one of the 2 small torx bolts that hold the top of the chain guide to the head and had to replace it with a same length and thread set screw and didn't seem to be fouling anything and the thread ended at the same point allowing the smooth half to act as a pivot.. please advise me if you have much experience with this horrible engine as you can't beat experience and without help I could be there for days... thanks for taking the time guys