Honda Repair: engine idling and hesitation when driving, honda cr v, honda dealership

Question
I have a 99 Honda CR-V. It began hesitating especially when air/heat on. Then one day parked and it started idling up and down and the check engine light came on. I brought it to a Honda dealership to get checked out and they replaced an IAC valve. Got truck back and drove out of town, it started hesitating again then killed on me. Was able to get it back started and able to get back home from out of town trip. However, brought truck back to Honda yesterday and they said that the idle was not adjusted properly so they adjusted it. This morning on drive to work, notice a slight hesitation. Once I parked the truck idle up and down and check engine light came on.
What other possibilities could be going on with truck? I'm getting very frustrated.  

Answer
Danielle:
It could be a fuel delivery problem. I hope the Honda dealer is going to make things right. I would talk to the service manager and make sure he/she knows the problem and gets it fixed, not just guessing as they seem to be doing. You may ask them to go on a ride with you if you can easily repeat the problem or you may see if they can drive it for a few days to make sure it is fixed.
Sorry I can't be of more help.
Let me know how it turns out.
Bill