MSefi.com read only forum (Jan.15,2018)

Ive been searching, and i have yet to find a legitimate reason i couldnt do this. If i wire the vref to the ecu signal power and ground the coils through the edis module, wouldnt this work just fine? Any reasons why it shouldnt? I assume the vref line is robust enough to handle additional logic level loads, so if im wrong please tell me.

When i say ground coils i mean the trigger ground. I know how to wire the coils so no worries.

anyone? ive read mention of doing it on here with v8 engines, but i have yet to find a sucess story on the matter.

You probably won't damage the VREF, although I would put a current limiting resistor in line with the VREF to avoid potential noise issues. While the MS itself would be OK, I have no idea what the coils would do if you attempted to wire them up this way, or if the power transistors in the EDIS module are a good match for them.

The edis module would be grounding the 5v signal line, which shouldnt have any amperage to speak of gking through it. My question is if the ls modules will fire this way. Grounding coils and injectors seems to be the common denominator in engine management systems, so i think im right, or at least close.

flyguyeddy wrote:The edis module would be grounding the 5v signal line, which shouldnt have any amperage to speak of gking through it. My question is if the ls modules will fire this way. Grounding coils and injectors seems to be the common denominator in engine management systems, so i think im right, or at least close.

I thought you meant grounding the power line - sorry, I'd missed the part about the signal there. Considering LS1 coils charge when the 5 volt signal is high, your signal would be the opposite of what the LS1 coils need - they will be overdwelled, fire at the wrong point, and probably overheat. There's a good reason you haven't seen a success story about this approach - it isn't going to succeed.

So the ls coils' ground the signal line to the main 12volt ground in addition to the signal ground? Whats the difference between applying a 5v signal to them with a hardwired ground and switchig the ground with a hardwired 5v applied to the signal? O

The problem is that if you are trying to ground the 5 volt signal with the EDIS module, it will be off when it should be on, and on when it should be off.

How so? Doesnt the edis module ground the coil to charge it? Isnt that the same thing that the ls coils do?

The LS1 coil charges when it is sent a 5 volt signal, not when the 5 volt signal is cut off.

well poop. i will just have to make a circuit to switch that around.