As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING ENGINE START, THE ENGINE RPM INCREASED TO ABOVE 2000RPM AND PILOT WAS UNABLE TO DECREASE RPM. MX FOUND THE THROTTLE CABLE HAD BROKEN INTERNALLY. INVESTIGATION FOUND THE CABLE HAD BROKEN AT THE APPROXIMATE LOCATION OF WHERE THE CABLE HSG EXITS THE FIREWALL.