EOC Injector kill on L36 "Ecotec" V6

[bobo333]

Hi Guys,

I have just started ecomodding my 1998 Holden Commodore wagon which has the Australian version of the L36 GM 3.8L V6, according to wikipedia its similar to the RWD V6s in F body Firebirds and Camaros, as well as the FWD version in a bunch of Buicks, Oldsmobiles and Chevys.

Has anybody put an injector kill switch on one of these? it has DFCO so im confident that killing the injectors wont hurt anything, but DFCO doesnt kick in often enough or stay on long enough for my liking so id like a manual version.

Should i just find the wires going to the injectors in the engine bay and hook a switch to them? or coming out of the ECU? How much power to the injectors draw? Should i put a relay in?

Thanks in advance

[bobo333]

I missed out on the most obvious option, pull the fuse!

So as a quick test i popped the Injector fuse out of the engine bay and replaced it with fly leads to a switch with an inline fuse, i then started the car, no warning lights is always a good sign!

Flick the switch off and the car stalls, flick it back on and it starts right up, excellent!

Then i re-ran the wires through a grommet in the fire wall and up to my gear shifter, where i taped the switch:


I then stuck my gearknob (aka tennis ball) back on top (you can just see the switch poking out from under it):


My first test drive around the block shows that it works perfectly, except for one problem, because ive tapped in to the injectors after the ECU the ECU is still sending the signal to fire the injectors and as such my fuel usage gauge still thinks im using fuel, will a scangauge have the same problem? can anyone think of a way to fix it so it shows actual fuel usage?

[RobertISaar]

if the PCM is commanding the injectors on, no datastream based fuel economy calculation will be correct, including the factory monitor.

you'll need to use something that measures pulsewidth directly, the MPGuino falls in this category.