225 OX66 help

[marcbejai]

the previously mentioned engine takes forever to start when cold, and when it finally starts, it would run normal for about 5 to 10 mins. After that the engine would increase rpm and decrease rpm intermittently on its own. This fast, slow, fast again, slow again motion would continue for a little while before it dies.
What could be possible causes of this continuous accelerating/decelerating?

[rodbolt17]

bad thermosensor,inccorect fuel pressure.
bad map sensor
incorrect TPS setting.
the list goes on.
all are easily tested.