After migrating ITCM to a new application server, existing database, the added engines are not listed in "caf status" and can't be started.
This happens because the engines are migrated from the database perspective-- they are in the ca_agent and ca_engine table. However, they are no longer in the comstore, after the migration. Engine plugins are added dynamically and exist, in part the database, and in part the local comstore. Hence they are lost during the migration to the new application. This is why they are not part of the "caf status" output. When DSM Explorer opens, it will list the engines because they are in the database, but they will remain in a stopped state, because these CAF plugins no longer exist.
Client Automation (ITCM) -- any version.
You should be able to delete using DSM Explorer. Just know the delete is not instant. The GUI makes it looks like they disappear, but it's the SystemEngine that will actually delete them. So if the SystemEngine is busy processing other tasks, it will get around to it later, when it says it's processing a system task. If you would like to clean them up manually, you can do so from SQL, just be sure to unlink all the tasks that are currently linked to them first...
-- Remove added engine ca_agent records
delete from ca_agent where agent_type=3 and domain_id in (
select domain_id from ca_n_tier where domain_uuid in (
select set_val_uuid from ca_settings where set_id=1))
-- Remove added engine ca_engine records
delete from ca_engine where domain_uuid in (select set_val_uuid from ca_settings where set_id=1) and label<>'SystemEngine'