AC shuts car down

[tsheppard]

Hi, I'm new to this and unfortunately don't know too much about cars. I just got a 95 Ford Escort wagon for paying for replacing a piston as it was running rough. Drove it for a few days and it started having difficulties starting when the AC on. So turned off the AC and it was fine until after a while I stopped at a stop sign and the whole engine died. In the mornings the car runs okay even with the AC on. When the car warms up the AC starts to shut the engine off. The car runs okay until you turn the AC on and then the engine stops. Just had it to a mechanic and they said it's the compressor. But the compressor seems to work great!
Also the car shifts rough (even though it's an automatic) and I told the mechanic that too and he said he didn't think there was a problem. This too only happens after the car runs a while and the engine is hot. I told him all that too.
A lot of people use this mechanic and say he won't rip me off, but I wonder...

[silverhand]

Hopefully you have this problem fixed by now, but if you don't, check the vacuum hose coming off the PVC valve. I had a similar problem, and the mechanic I use went right to it. The problem actually started with an occasional stalling that didn't seem to be a big deal, but then we had a hot spell and I started using the AC, and it would stall at idle with the AC running. The problem got worse to the point where it would stall without the AC running, just when it would idle.