hmm. did your motor start rocking before or after the timing belt change? is it hesitating any?

 

My 04 neon sxt has about 47k on it and it will act like it is going to crank but wont turn over. after several trys it did turn over but the check engine light remained on. what could it be. Only had the car about 2 weeks. runs great and is in great condition. I have seen a car fax report on it and it said it had a new battery and starter installed at 35k. what could be causing this.