is it an 8v? if so i assume it'd be a digifant. sounds like somethings not quite right! you'll know if you've got a pulley by taking off the top cam belt cover (if its got one) and looking at it. if its standard it'll be one piece, if its a vernier it'll be two piece, normally ally and anodised a nice colour with a few bolts allowing you to advance or retard it.
on digifants things like this are often down to bad earths and other electrical problems rather than mechanical. check your earth on the gearbox for corrosion and clean it up, take your air inlet to the throttle body off and have a look at whats inside, it might be full of crap so get some carb cleaner and flush it out. check your rocker cover breather and the bung it sits in for any damage. and might be worth changing the blue temp sender at the front of the head between the 3rd and 4th spark plugs.
best iu can do at the moment!