92 Olds 3.1 Intermittent Idle Problem

I have a 1992 Oldsmobile Cutlass with an intermittent idling problem. I have found no codes in ecm. After checking a few things, I gained access to ecm and removed prom cover and performed the 'wiggle' test. Every time I put slight pressure on prom in ecm the engine would die out. From past experiance I have learned to replaced ecm and this would correct this problem. I replaced ecm , but still get idling problems at times. I can push on prom in new ecm and it does not affect idle anymore. Tried known good iac valve-didn't help. Also plugged in iac tester and it showed ecm trying to step idle up. I cleaned throttle body and checked for vacuum leaks but still no help. I am wondering if maybe ignition module cutting out at low rpms? If anyone can shed some light on this problem I would appreciate it.
Thanks ahead of time. Mark P.S> fuel pressure 39psi minimum when it cuts out.

What does an intermittent idling problem consist of, misfire, rough idle, low idle, high idle?

Sometimes the engine just dies. It will always start back up, but you have to crack the throttle a little. The transmission is in park also. It does seem to run a little rough when it does this, but I don't think its a miss fire.
Thanks, Mark.

Remove and clean the iac and ports, also do the same to the egr. If you can scan it look at the tps activity.