92 Riviera no start

Has anybody figured out what else can be wrong on a 92 Rivi that won't turn over but has a good battery? I replaced the ignition cylinder and vats switch in the column ($100) and it still does the same thing. I put a remote starter switch on the starter and turn the key over - nothing, now push the remote starter switch with the key turned over and it starts right up. You can also let off the remote starter switch after bumping it and the key switch will continue to start it that one time only. If you turn it off you have to use the remote switch again. Is there a starter relay somewhere that goes bad? bad ignition switch (lower column switch)? relay?
Any help is much appreciated!

I also now have an intermittent check engine light. No error codes in the system either, it just comes and goes and seems to go away more when a vacuum increase happens like letting off the gas pedal.