Starting problems... again....

I couple weeks ago, my mom was complaining that hte car wouldn't start... but I dind't see a problem. Took it to 4 diff mechanics, and all of them said the car was fine. Today, I drove around alot, and the last two or three times I started the car, it sounded like it was really struggling to start (but it started no problem). I'm kinda worried... what could be wrong?

***Update:*** if I give it like 25-50% gas as I start it it starts up fine.

Any help would be greatly appreciated, thanks.