Bad texter or not interested?

So I met this guy and we hit it off pretty quick but he is very short on text messages I feel like he likes me but I'm not used to the short responses or him just not texting back for hours? Last night he called me for the first time and we talked for 3 hours and it was great and now today we have barely talked. He is 5 years older than me. Do you think that makes a difference? Or is he not that into me. I am scared to waste my time because I have done so before. Any tips?