Quote Originally Posted by AlexanderHL View Post
Hi

Searched forums and internet for answers regarding this, but im still unsure.

Does the TBI injectors care about polarity?
The TBI housing have different grooves so that the injectors can only be assembled one way
Each in 180 degrees rotation from the other. So positive should always be on the outside, and common ground in the center?

However the official drawings doesn't indicate this when describing the coils in the injectors, it also doesn't indicate if injector 1 is on cylinder bank 1? I assume this is the case? However the wires comes from the backside, not the front as in drawing..?

Attached photo from 89 g20 wiring manual.
Take a look again at your drawing. Yours shows Red/Red, is that right? Here's a diagram for my 88. Red and White are positive while Blue and Green are negative (grounded by the ECM. IDK if polarity matters, why not wire them the way they were originally?

The Intake manifold is designed so the injector on each side feeds the 2 center cylinders on that side and the 2 outside cylinders on the other side. These are fired synchronously, meaning they take turns, and if you look at the firing order, each one will fire for their assigned cylinder.

1988 Injector Control Circuit.PNG