Do those of you that use the stock harness use the injector power(5V) from the MS or the stock ECU. The stock wiring diagram for the 96 indicates that cutting the 5V to the Injectors will short out the EGR/TPS/MAF.

I had one very bad experience with the 5V system with a Stock ECU and would like to avoid another mishap...

 

Straight from the MS and no problems at all with it.

 

Hello Jefe,

I'm not sure why you would want to cut the power to the injector.. Let the stock ECU feed the 5V to them. It is easier since you have no wire to add.

My MS is only dealing with the ground part. So you only need to cut the injectors ground and wire them to MS.

This way I only have the 4 injector ground wire to connect back to the stock ECU if any problem rise from the MS.

 

5V? Don't injectors use the same 12V power source as the MS? I just made a new harness for my injectors according to this:
http://www.megasquirt.info/ms2/v3ext_wiring.gif

 

You are right!! It is 12V.. My bad.. I meant I let the stock ECU feed them wathever voltage they want and only control the ground through MS.

I guess Jefe confuse me when he start with the 5V part
If you need 5v.. couldn't you just splice in any 5V source the Ecu is feeding his sensor?

 

MiataMath,
Thanks!
That's how I was going to try it first, I can't ever ditch the stock ECU because I live in a wanna be CARB state and have to keep my OBD II ...

Aussie,
If I could entirely ditch the stock ecu like you did I would, but since I have to keep it, KISS.

My powercard only uses the injector grounds as well...