Every engine has intake and exhaust valves for each cylinder as well as one spark plug for each cylinder. The injector sprays fuel and before the intake valve then the intake valve opens it allows the fuel to enter into the cylinder then it is compressed by a he piston the spark plug ignites the fuel and pushes the piston down and then when the piston comes back up the exhaust valve opens and allows the burned fuel to go out the exhaust. Hope this answers your question..
