Does anyone know of any GM v6 mpfi that doesn,t fire it,s injectors all at the same time? It is my understanding that no matter what you have, whether it is TBI,TPI,MPFI, SFI, If you have only one injector driver in the ecm then you can,t alternate anything as far as firing one injector different than another and you can,t alternate banks either, correct? No matter if the engine is a 4,6,8 if you only have one injector driver, all you can do is turn all the injectors either on or off at the same time. I,ve asked this question all over the web and as far as the v6, can find nothing that says the injectors fire anyway except simultaneous, meaning all at the same time. As far as the v6, I,m excluding TBI and SFI. Any thoughts, thanks

 

I coulda sworn that all of our injectors aren't fired at the same time. We have a left & right bank... ?

 

I know that the at the lest the 3.1L fires the left then right bank. I'm not sure about the 2.8L though, but sence they are so closely related you would figure it would be the same. It would be nice to SFI. It would give even better fuel economy!

 

The 3.1L w/the '730 ECM fire all injectors at
the same time. Only one injector driver, two
pins to carry the current.

GN's w/the '148 are SFI and can/do fire each
injector individually. That ECM has 6 drivers.
Code/hardware also supports DIS.

RBob.

 

It is my understanding that the 3.1L and the 2.8L both fire all their injectors at the same time. As far as mpfi, I only know of one engine that alternates injector banks and that is the 92-93 LTI Vette. I have a 2.8L vin W, it,s a fwd. I did an ohms test with a dmm at the four wire injector plug at the back of the engine, Between the blue and green wire, at the plug that goes to the ecm. The blue is ground for one injector bank and the green is the ground for the other injector bank. The meter showed 0 resistance, continuity, that means that the two wires are connected and that all my injectors fire at once. My wiring diagram also shows only one injector driver. Alternatingly fired injector banks are very rare, not the general rule. I believe the GM quad4 fires it,s injectors in pairs. I believe there are some TBI that have more than one injector, that alternates the injectors. But that is all I can think of. thanks

 

JD, I'll go over my GM book this weekend, and see if it mentions anything.