AC Compressor would not come on this spring. Had the system charged this morning, (it took the whole 2.2 LBS.) Worked great until this evening, then I noticed the compressor working intermittently....on, off, on, off. There was no "noticable" leak detected during the AC service this morning. I'm guessing there is a leak nonetheless. Of course, no appreciable cooling is going on, either. Where could leak be coming from? Does this sound like a compressor problem? I gotta tell ya, I've serviced the hell out of this car and at 100,000 miles, it's starting to go belly-up on me. Any help would be appreciated. Thanks.

Dave