Cutting out problem

Hi, i hope somone can help me. I've a toyota Celica 1992 with the 3sge engine, the problem i have is that after my car has run for an hour then cuts out & will not start, after about 10-20 minuites it starts again.Also when it's not starting theres no spark at the spark plug.
It's showing code 14 on the diagnostics, i've replaced the ignighter & coil but no difference.
Does anyone have any ideas? :confused: