92 4.3L throttle body w/2 injectors. Intermittant Missing on Cold Start
 

The engine seems to be firing on only one side most of the time on cold startup, but always starts. Clears up as it runs a few minutes and begins to warm up. Thorttle body clean under injector on one side and shows gum deposits on other side. I suspect a bad injector. Would love to have some ideas to point me in the right direction for a cure. Thanks all, Mike

what does the injector spray pattern look like?