My sierra was a bit hesitiant at the tail end of last week, i didn't get the chance to look at it over the weekend and this morning it was very spluttery on half-full throttle, it seemed to run fine when it was just coasting along. Tonight on the way home it dropped a cylinder which came and went again between half and full throttle, i suspect a knackered lead.

The car's parked at the bottom of my street with no street lights above it, no way of me getting a light to it and no chance of me rolling it down the drive to get the light from the garage so before i go out with a torch and have a fanny about can anyone tell me what/if there's a common cause or am i just going to have to check the leads/plugs/dizzy etc?