Can fuel injection systems be adjusted?

Yes, fuel injection systems can be adjusted, but the extent and method of adjustment depend on the type of system and vehicle. Modern electronic fuel injection (EFI) systems often use engine control units (ECUs) that automatically adjust fuel delivery based on various sensor inputs. However, tuners can modify the ECU's programming or use aftermarket tuning tools to optimize performance. In contrast, older mechanical systems may require manual adjustments to components like the fuel pressure regulator or injectors.