Student formula competition requires modification of the intake manifold hole by 20 mm. The internal combustion engine used has a capacity of 600 cc and an intake hole of 45 mm. The intake hole reduction affects the performance of the internal combustion engine. The ratio of the amount of air that is too small causes a decrease in engine performance. Ignition remapping is needed and fuel injection on the internal combustion engine. In the remapping process, the ratio of air and fuel is adjusted to the needs. The standard ECU on an internal combustion engine cannot be remapped. So the standard ECU on internal combustion engines is replaced using Motec M400. The parameters on the engine are only added to the camshaft sensor to determine the ignition timing and injection. Other sensors such as throttle position sensor, manifold absolute pressure, intake air temperature sensor, and engine temperature are used to determine ignition mapping parameters, fuel injection, and compensation for cranking, idle, and acceleration requirements. Tests obtained ignition remapping and fuel injection on internal combustion engines using ECU.