Taking your car to a mechanic for fuel injector cleaning will involve removing the injectors from the engine and performing the service on a bench with special machinery.

In this tech guide Stephen Lim examines the benefits of cleaning fuel injectors and debates whether or not you should rehab your old EFI system parts or just buy new ones - Hot Rod Magazine ...

The flow-rate test determines actual injector fuel delivery. The injectors are allowed to run until the fuel level shows around 100 cc, in order to easily find minute differences.