Abstract: Some embodiments of the present disclosure include a system for allowing spark ignition fuel injected engines to function on a plurality of fuels. The system may include an engine system including an engine control module operatively attached to a fuel injector, and a fuel tank attached to the fuel injector, a fuel content sensor configured to sense a content of a fuel in the engine system before combustion of the fuel, and a fuel control module placed inline with the fuel injector and the fuel content sensor, the fuel control module configured to receive fuel content information from the fuel content sensor and make a change to the fuel injector pulse width based on the fuel content information, if necessary.