my 89 prelude doesn't always start.......

Everything checks out, according to my mechanic. The alternater, starter (which is 6 months old), the battery (a 770CCA Interstate) all good according to him. However he told me that the starter pulls 260 amps sometimes rather than the normal 180 when turning over sometimes. When the car won't start, it can be jumped. Go figure.
Any help would be appreciated.

what is the car doing exactly when you try to start it, clicking making a buzzing noise?