Back fires when attempting to start, will not start

My name is Michael. I live in Zambia. I brought a Toyota Land Cruiser from Japan. A 3 door Prado RZ petrol engine. It arrived okay via Dar-e slam and drove well to Lusaka. After picking, I drove for about 540 km to my destination. Next day, the vehicle drove few meters and the engine switched off. I tried to re-start and failed. Third attempt it drove for 5 km and the engine switched off. I have been trying since with no success. The diagnostic showed fault indication on codes: 14, 21 and 34. After cleaning airflow sensors, faults 21 and 34 were cleared, but still the vehicle could not pick after cranking. It is giving a back-firing sound. What could be the problem and how can it be solved? I have the vehicle only for a week now.

Hello everyone, I just checked the engine details of the Prado. It is Model: VZ J90W - GJMGK; Engine: VZ - FE; 3378 cc.