94 Buick Park Ave won't start

I have a 94 Buick Park Ave that wont start I had it to a machanic and they replaced the cam senser and the crank senser, said if it done it again the emc needed to be replaced, I did that and now it won't stay running for more than 20 sec. need help please.

did you transfer the prom to the new pcm.
check ground wires under the coil pack make sure they are clean and tight
good luck
michel

Sounds like you might need a new machanic. To keep replacing stuff till it works is stone age. An up to date shop will have invested heavly in diagnostic instrumentation and update training. This makes them expensive, but damm well worth it.