Engine cylinders not all firing

I have a 89 Cutlass 6 cylinder. 2 and 4 cylinders are not firing and I've tried everything. Can anybody give me an idea as to what might be wrong?

Welcome to AF. Checked for wires crossed, bad compression, blown head gasket, dead injectors? Your query is too general for any definitive answer.

Welcome to AF. Checked for wires crossed,bad compression,blown head gasket,dead injectors? Your query is too general for any difinitive answer.

Please look at the dates before replying, this thread is too old, thanks.