Hello Daryl,
It is hard to check these without a tester. If there is not an injector tester near by, a diesel truck service center may have an injector tester. The do-it-yourself alternative is: if you have a spare injector line, unhook one line on your pump and hook the spare line up. Route the line so it can be used as a tester for the injectors. Of course your engine must be running and it will be running on only five cylinders (remember last years tech session). The injectors have a fine cone shaped spray pattern when correct. They also sound off with a distinctive "chirp". Always be careful when working with gasoline (fire hazard). Keep a fire extiguisher close and have plenty of ventilation. Flushing the injectors with WD40 could help. The little cone valve on the end of the injector can be lifted open with your fingernails and then flushed.
Joe Alexander
Blacklick, Ohio