Discussion and questions related to the course EFI Wiring Fundamentals
I have a question regarding wiring coil on plug ignition. I have a 1jzgte and am completely rewiring the harness from scratch. I want to simplify things and make them easier to service. The Igniter used to be in the engine bay, but I would like to move it to the cabin under the dash next to the ecu. The new set up will have the wires from the igniter going through the entire loom to the coilpacks. the coilpack power wires will also be going through the entire loom. I have milspec wire and all critical sensors are shielded (KNK, CRANK, CAM). The power to the coils will come from it's own relay, separate from the ecu and EFI. I will also be keeping the Toyota factory noise filter. Attached is a schematic of the engine harness. everything in the blue box is wrapped together in the engine harness bundle.
Does anyone see any problems with this setup?
Unfortunately, every situation is different, and there really isn't a way of knowing whether you will have problems, except by trying it. I can say that I've used ECU's with built in igniters in the past, and have run the coil primary negative wire back through the main harness, and not come unstuck, but that build was to another engineer's specification, and not the way I personally would have designed the system.
I would lean towards saying, that with the precautions you've taken, you're likely to be okay. Still try and keep the ignitor away from the ecu though :-). What coils are you going to use?
I was going to use the stock coils wired to a hks DLI (old school) twin power. it gives the sparkplugs a double tap. I have been considering trading up and going with LS coils however I am most likely only going to make 500ish HP. which i have used the stock coils and HKS DLI in the past with no issues.
I've done something similar in the past and threw the book at the harness RE: emi mitigation. Worked well but I don't know if I'd do it again.