How do I troubleshoot the dead tachometer?

[jjgolf]

I understand the tachometer must work or the ECU cuts injectors. My tach. does not work, killing my injectors. I do have spark. I tried the jumper wire at diag. conn., cranking for 10 sec., but only get code 12. Bad ECU? Am I beating a dead horse and just need a new ECU? You mention in my other thread something about no tach. feed? Brown wire? Suppressor? I did find the suppressor. Can I check it? My chilton's does not show anything about the tach. I know.. I need FSM. I see a brown wire at the suppressor, and one at the back of the instrument cluster. Maybe I just have a bad tach.? I did notice what looks like junkyard marker pen #s on the cluster when I pulled it. Just point me in the right direction. Thank you for any help/advice. (I also know I need to learn how to maneuver/respond/reply
in these forums. Forgive my ignorance.)
jjgolf