This is all on a 1.9 XUD engine from a peugeot boxer, using the cambelt kit for a 306, still, an XUD model Mark, a friend came round today, joined me mid sessions to change a fuel pump to see whether the 11mm was causing the timing to constantly slip out. So the procedure went as follows; locked the fly cambelt tension off cambelt off pulleys (cam and fuel pump) fuel pump removed new fuel pump on locked cam locked fuel pump cambelt back on tension on remove locking key manually crank a few times recheck timing - all fine Great, so we start her up, after a while of chugging away she lives. Fine. LOT of white smoke, so we retard fully, still lots of white smoke, hmm maybe we're doing it the wrong way, so fully advance, still lots of white smoke... Hmm, lets check the timing, 180 out AGAIN!! PLEASE someone tell me what on earth is going on? this is the third time the timing has come out, twice on the 11mm, and this time, on the 9mm. Myself and mark, completely stumped. Also, the belt has a lot of "slap" when the engines running, i've got a video. whether this has anything to do with it at all, im not sure.