Abstract: A fuel injection control system having an intelligent timer (TPU) to perform fuel injection control using the TPU even on request of asynchronous injection which is not synchronous with rotational angle signals. A central processing unit (CPU) calculates a value to be used during the execution of a synchronous injection (e.g., a fuel injection time) and an asynchronous injection time and stores these values in a parameter RAM. The CPU determines whether there is a request for an asynchronous injection from, for example, the quantity of a change in the opening of a throttle. The TPU also executes a synchronous injection if there is no asynchronous injection request. If there is an asynchronous injection request, it transmits an on output from input/output pins and causes a compare register to store a value which is the sum of the current time and an asynchronous injection time. It transmits an off output from the input/output pins if this value agrees with a value in a first free run counter.