Q: What would cause my car to die once I release the ignition switch on 1991 Mercury Capri

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
My car starts but dies immediately once I release the ignition switch
(1) Answer
(1) Comments
Most likely is switch , but is fuel pump cicruit also a possibility? comes on for 2 sec 'crank' then relay releases in run position?Or other related part of control system. ALL can be tested , but yes if we only have a choice of one part for now , Id go with the switch...............never mind.