V8 injector wiring

[hatchssv8]

DW- do you know if there is any literature available that explains how the injection is managed.

An event table would be the ideal thing that I am looking for.

Just thought of something?????????? If the 808 fires all injectors together, then if it is so important to group the injectors (according to the wiring) then the 305 would use different timing/ qty per firing of injectors per cycle and different pulse width per firing. (hope that makes sense)

[VL400]

The VR V8 still has batch fired injection - the first V8 to go away from this was the VS V8 Series 3 with sequential. There is no cam/sync pulse so all 8 injectors are fired together (ie both injector drivers get triggered at the same time) on every 4th reference pulse while in double fire mode - so two injection events per engine cycle. It can be setup to single fire mode so one injection event on every 8th pulse. Due to no cam sensor the injection event can happen anywhere through the firing order the only known is it will be on every 4th/8th pulse.

The VR V6 Auto uses a cam sensor to have banked injection.

[UCMatt]

With a VT distributor giving cam position, the Auto V8 could be setup in group mode as the V6 is.

[hatchssv8]

Agreed VL400.

There is a significant change in electrical architecture on the VR/VS wiring for the injectors. the changes also add cost and complexity to the previous set up (VN/P), if the ECM event did not change (ECM still triggers all injectors at once) then why make such a radical change to the wiring?

Out of interest, do you know what the spacing between injection triggers is when utilizing double fire per engine cycle? I would think it is every 270 crank degrees



PS: Can anyone refer to the VR/VS Holden workshop manual (Probably under V8 Engine management).........I have a feeling it might be explained there.......I only have VT onwards.

[VL400]

The PCM was used in the V6 auto where they did use the banked option. The V8 may be part of GMs failsafe mode, where the '808 would just stop you could get home on half the cyl if the driver failed open circuit.

Double fire is twice per engine cycle so an injection event every 360 crank degrees.