I've read the threads here that say the stock grounds are not up to par for running low Z injectors. After assembling my MS v.3 i've been thinking of how to tackle this issue. I purchased the 23" wiring from DIYAT and that came with 2 wires designated as grounds that I wired into the stock grounds via a boomslang type patch harness. In doing so, these 2 ground wires were joined to the multiple ground pins on the db37 connector. To add the extra grounding needed for the lowZ's, I was thinking of adding more ground wires to those pins and running them through the firewall to the stock ecu grounding point. This should allow for more current flow and not introduce any ground offsets. Any thoughts?

 

I take it you put the 2 ground wires on 7-9 and 17-19? Just add 3 more 18-20 awg wires to pins 10-17, your pick. Run them to a single pin from the DB37 to the stock ECU grounding point on the motor. That should be all the grounding you'll ever need.

 

I did what you are preposing, I ran 3 extra 16 guage wires from the db37 to the intake manifold. the wires join at the intake on a lug that is bolted down. For the hell of it, run like 5 or 6 as you will later wish you had an extra ground like for Knocksense, or a sensor ground for the wideband, etc.

 

Correct.
Sounds good. I didn't realize that pins 10-17 were connected to ground as well. Thanks.
Makes sense to do this so that you have wires ready for action when you need them. Thanks for the tip.

 

The only issue with running tons of wires to the DB37 is it makes it more and more difficult to get the DB37 closed appropriately.

 

i did everything i really could to create appropriate grounding, but still ended up with voltage spikes in the power supply caused by the lo-z injectors.

 

With the V3.0 board? Did you build the injector flyback circuit?