Hi Guys, 2 points

 

1 Which pistons are serviced by which spark plug/that long black thing that does the electrics,(see what i mean, my brain has gone)

 

What i mean is , if you are standing in front of the car looking at the engine you have 3 cylinders on the left etc..., at angles both on the left and right are the spark plugs and , i remember ! Coil packs (phew!) but does the , for instance, first plug/pack on the passenger side (your right) fire up the front left or right cylinder. Without ever stripping one down or being able to find some piccys, i'm finding it hard to work out in my head. Because it goes between the inlets on the other side, in my mind, the ones on the right, service the cylinders on the left.am i right, wrong.

 

Dont worry once i've gone you will no longer have to put up with my brain injured questions...

 

2 the 300zx pdf manual has this diagram for piston numbers, is it right?

That is correct diagram, right side coil packs fire right side, left fire left side.

The coil pack is directly on top of the plug, the plug is in the centre of the roof of the cylinder if you like. So where ever the coil pack is the Cylinder it works with is directly underneath. There's videos on YouTube etc that show how an internal combustion engine like that found in cars works, that may help you a lot.