Here's what I did to check my injectors. I had a friend in the car, I took off the fuel rail and held all the injectors on with 2 hands, as tight as possible, I had him turn on the car, and prime the fuel pump, after there were no leaks, I had him crank the car, then I saw each injector fire the right way, try that, if 1 or 2 injectors is firing weak that is def your problem. Kind of a ghetto way to figure it out, but when you dont have professional equiptment at ur hands you think of things. Let me know how it worked out.