You can pull the injectors out and by lifting the air flow plate while the ignition is on the fuel pump will run to pressurize the system and you can watch for any drips. If the injectors are leaking you may want to try a tankful or two with a quality injector cleaner additive (like concentrated Techron) before deciding to replace them. Probably a more common problem is leaking injector seals so make sure you check those first. Spray some water or carb cleaner around the base of each injector while the engine is running. If the revs change you've got a leak. New seals are easy to install (do all of them).
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Dave -not to be confused with a real expert, just goofing around at this