car cranks but doesn't completely turn over and start running on 2001 BMW 325i

If my car cranks and doesn't click, then does that mean the problem is likely the fuel injector. I want to know if I can afford the service before I get it towed. AAA came out and helped me start the car by banging on the fuel tank? with a wrench while I was cranking it. Does it sound like the problem could be the fuel injector????

Asked by for the 2001 BMW 325i