how do i check the injector pulse on my s10, on 1990 Chevrolet S10

i've got fuel to the throttle body but not thru the injectors

Asked by for the 1990 Chevrolet S10
It's a longer answer but there is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate
The best way to test injectors is with an oscilloscope with a knowledge of good versus bad patterns but what you are looking for basically is longer on time as the engine RPM raises.
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All you need is a noid light to check injector pulse. You can buy that at a harbour freight store or NAPA.