Injection Timing/tuning

Another big headache is tuning the injection. Injection timing requires inputs from various sensor such as RPM, MAP, MAT and so on. There are two basic method to calculate how much fuel need to be injected. One is using mass air flow sensor (MAF), and another one is MAP(manifold air pressure) so called speed density method. The MAF methdo is easy but the sensor is costly compare to the MAP. Malaysian car for example, PROTON, used MAP sensor to determine how much air going thru the engine and compare the air with a tabled value called air-fuel-ratio.Thus, the algorithms to calculate the injection timing may be different from one car manufacturer to the other.