I may be mistaken, but don't glow plugs go with diesel, and spark plugs with petrol? and you have a glow plug, no? The pump is self metering and also adjustable... if you tightened the adjustment all the way in, then the pump wont work, it's adjustable by way of limiting the membrane travel... this is done on the outlet side of the pump, it's not supposed to be screwed all the way in.
The glow plug just ignites the fuel - if there's fuel pressure there, the flame sustains itself. You're right about the pump. If the adjuster end's been off, the flow rate'll need setting again.
You just do it for attention. Raise you a hand held kids school drink bottle and clothes pegs on the battery.
