Tried that, no knock on other cylinder, it does have some black smoke.and a dead miss fire.tried remove injector tubing to that cylinder. It runs smoother on four cylinders. Put tubing back on injector and it knocks hard ! I started this project because cylinders 4-5 weren't what seemed to me getting enough fuel. So I took an injector pump from Mrparts car and installed it. Never could get the timing right. And I couldn't use the lock pin tool on it, different year Model .so back to origin injector. I rebuilt the fuel pump. But know the knock issue