how to check injectors?

Does anyone know how I could go about checking that an injector is pumping without removal?

get yourself an mutlimeter and attach the leads to the electrical part of the injector, find the voltage it should be reading while the car is running and match that to the the number you read off the meter, if the number is lower, than you have a fualty injector, or faulty wiring, causing the bucking you may be expeperiencing from your other post.