If the vehicle has not been started
If the vehicle HAS NOT been started DON’T turn the ignition on this will engage the lift pump in the fuel tank sending fuel up to the engine ready for ignition.
If the vehicle has been started
If the vehicle HAS been started DO NOT re-start as this could cause further damage to the fuel pump and injectors. Petrol can cause damage to the engine as diesel acts as a lubricant when passing through the fuel pump and injectors. Petrol is too thin and does not lubricate any of the moving parts causing excess wear and perishing any seals it comes into contact with. This could all be a very expensive fix when taken to a garage.
However, in our experience the vehicle usually breaks down before any permanent damage is done. We flush the fuel system with fresh diesel which will re lubricate the fuel pump and allow the engine to start. as per manufacturers advice and our experience we never recommend any fuel system treatments as there is no evidence they work and will only add to your expense.