Roy, the TBI gets a fused 12V straight to the injector, and grounds through the quad drivers in the ECM. Injector pulse width is set at a 50% on-time default setting and the amplifiers use the sensor inputs and the O2 sensor signal to add or subtract from that point to fine-tune the mixture. The correction is applied anywhere from 10 to 90 times per second, depending on the clock frequency. Much more accurate than a carburetor!
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!