Why would one injector spray and the other not on my 1989 k1500 5.7
Just a bad injector, probably plugged, just double check that there is voltage at the plugin on top of the injector. Otherwise just replace both injectors.
Could be a bad a injector, or the injector driver for that injector, you need to test for both power an trigger signals at the injectors, if you loose either of these the injector will not flow, If you have power but no trigger then trace the trigger wire for a short, if none are found the check the signal right at the ECM if no signal exists then it it the ECM.
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