help again pls

ok lately my car has been taking a couple of seconds to start (normaly 1st tick)
whats the normal culprit for this plugs? dizzy? leads? rotar arm? would 1 of these be the sucker?

what car is it ? if a gti could be a leaky injector amongst other things, is it only after it's been stood a while ? leave it to stand for a while then take plugs out and have a sniff using a pipe (honestley no wind up )