Hi, my name is Jan and I'm a 54 year old female who has been playing mechanic all of my life. I've got a '92 'Stang here with an intermitent ignition problem. It'll be running fine, then the tach will drop to zero and the motor will run roughly. Then often the tach starts working again and the miss goes away. So after attaching my code scanner in KOER mode, it threw two codes....998 (Hard Code) and 224 (IDM malfunction). I know that the IDM monitors the ignition input to the PCM, but haven't a clue where my problem lies. So far, the only thing I've tried is pulling the SPOUT, with dropped the tach to zero and made it run rough. Any and all suggestions as to where to go next would be greatly appreciated....

Thanks,

Jan