Im with the above in terms of moving him to one sleep. The transition for me was a bit hit and miss as well to start off with, but I found that lunch at 11am (I know it sounds like a crazy time, but it works, and still works (he's nearly 3) and in bed by 11:30am. He couldn't stand it much more than that for ages, but its only been recently that he can go until mid-day if need be, but its, still, in bed by no later than 11:45. If he's an early riser, I hope that this time frame is useful to you. And also check for teeth. I found that both the kiddies if they were a bit unwell with teeth had poor day sleeps.