94 grand am se 3.1L v6 fuel injection problems, please help!!

94 3.1L v6 grand am is vibrating terribly when accelerating over 80km and it is also misfiring ( it jerks back when accelerating) I took it into my mechanic and he told me that both front axiles needed replacing and that engine was running only on 5 cylinders.. did an engine compression test and found a faulty spark plug and wire..replaced them and engine continued to misfire. Now he tells me that one injector is either dirty or damaged and to either do an injector flush, which sometimes solve the problem or manuly opening engine and check for damaged injector, which time consuming and costs money. isn't ther a test he could perform to check the flow of the injector without literaly checking each one manualy?