timing off

Hey everyone. This is my first post. I bought a 92 Grand Am for $300...as far as I knew it needed a head gasket and a thourough tune-up. So, seeing an opportunity to turn wrenches and get this thing running, I changed the head gasket, etc, etc. Well, the car is back together now and running, but I've been unable to diagnose a stumbling on acceleration problem and fuel in my crankcase! I've tried an O2 sensor, new fuel press. regulator, fuel filter, checked for vac leaks, etc. I've read the forum threads and can't seem to put twio and two together. I brought the car into GM and they said that the timing was way out and that they needed to take the cover off and redo the timing with "special" tools. I feel 99% confident I did the timing right the first time...is there anything else that could be causing the timing to be out (knock sensor, ignition module??). The timing seems to have gotten worse...it used to grumble for a second when I hit the gas, then smooth right out...now it is starting to last throughout the rpm range. Sorry, a little long winded...should I trash this engine and start off with a rebuilt? Thanks.

Wonder if the Crank Position Sensor is dying. If , as U think, the timing was good, the CPS could be cause of current issues.

Did you have the head pressure tested?

Thanks for the replies. I guess I should've mentioned my engine is a 2.3 Quad SOHC. I unplugged the CPS a few days ago and the car wouldn't even start, so unless its just not working properly, it does seem to be doing its job...is it possible that it's slowly dying on me? Also, I haven't done a compression test yet, although I removed the plugs and found one pretty gunked up...I'm assuming this means I have a bad ring, and that's what's throwing off the timing, and dumping fuel into the crankcase.