Hard start on my 2005 Nissan Altima

My 2005 nissan altima has been experiencing hard start issues over the past year. It usually happens when the engine is hotand will eventually start after a few tries. If it's been sitting for more than 30 minutes it starts up fine. My check engine soon light comes on as a result and I finally went and go the codes read which said it was the crank position sensor a common issue with Altimas. I went and had a local mechanic replace the crank position sensor and when I went to pick it up at the shop it wouldn't start! Sure enough the mechanic had just moved it outside before I got there so the engine was hot. He's going to look at it again tomorrow but what could it be?