Hello,
My name is Robert Gallopo I built a 1.8 motor did some wiring but didn’t touch the engine harness other than putting some EV14 or EV1 connectors on the fuel injectors for my id1050x injectors. I also completely removed the dash harness that I have in the car and kept what I need to keep like the turn signals and hazards working. I also have a fuel return fuel system and a constant on fuel pump DW200 with its own relay and power. I click on ignition, fuel and attempt to start but volt will randomly drop to 6ish/7ish volts and kill the ecu and it does like a bog when it does since it’s also taking voltage from the starter but when I flood clear (turn off injectors) or completely removed the injectors by disconnecting them it’s fine cranks around 9.5 volts. Does anyone know maybe it’s some high resistance in the injection harness or a bad fuse? Is there a ground in the dash harness I’m missing? Any ideas for help will be awesome.

Things I’ve already done was check and reground the engine, ppf, dashbar, grounding bus bar and they resistance check good.

thank you in advance for your help and understanding.

 

Sparkplug wires backwards is my first guess. Try swapping 1&4, and 2&3, and see if that fixes it.

 

patsmx5,

could this cause a volt drop that bad?

 

If it fires the motor backwards on the starter, yes.