Replaced PCV, now won't start

I have a 96 mystique, with a 4 cyl engine in it. The car idled rough, and when I started it cold, it would stall almost immediately (once idle dropped down), but then it would run fine. I thought this might be the PCV valve (original equipment, and the car has 120k miles on it) and so I replaced the PCV valve (the engineer that placed that one should be shot). Anyway, when I started the car up again, the engine wouldn't stay running. It would idle down and die, even after it had been running a little bit. This problem got worse. I started revving the engine to see if it just needed to heat up a little bit, but when it got up to 4k rpm, it kind of revved, died, revved, died, revved died, then it dies for good. Now it won't start. What happened here? Any ideas where to start?

Thanks,

NavyGuy

the rev,die,rev,die thing is a rev limiter so you dont blow the engine. mine does it too. its a safety device.