Small Engine Troubleshooting Problems? Ask a Mechanic Now.
What engine? Sounds like the fule solenoid is dropping out. It has to stay open or fule is shutoff the injectors. The solenoid has two coils and one is engaged with the start cycle/glow plugs,and otheris the hold coil, which has to hold solenoid after the start coil pulls it into position. Sounds like the hold is not working. Test solenoid for battery voltage when key is on. If it has voltage, the solenoid can be bad, or may need to be adjusted so it is at full travel .If it does not bottom out, the small hold coil will not keep it open.