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

New to the forums but not so much to the Megasquirt 2.2 platform. I had a 22RE running Megasquirt, both via Ford TBI and 22re OEM-that was fuel only but the harness left much to be desired.

My *new* 8 year old project is a 1974 Toyota Corolla that has a 2TGE (Toyota twin cam 8v 2.0 4cyl with OEM efi manifold) with a turbo and EDIS. I took the week off to get this harness done and the car running. The MS version I'm using is still the original 2.2 Grippo board, but with a newer relay harness (purchased late last year) and a relay board of the same vintage as the harness. I have some specifics that I hope can get answered while I still have a hot soldering iron and all my NEW labeled wires I just purchase from DIYAutoTune.

I will be using 2.2 ohm Ford injectors (44lbs @33psi) and utilizing a stock 83/4 Toyota Celica 22re injector ballast resistor. The resistor has 1 wire in and 2 wires out configuration, so my MS mentor (who has a N/A 2TGE running with the same setup with EDIS) said that I can run my injectors from the Fuel Pump relay as it will handle 15-20 amps. Which is totally fine as I was planning on using an external relay for the fuel pump anyways (+12v switched and a Ford impact cutoff switch). * I found the resistor was needed on the 2.2 board (without flyback mods) as I burnt up a set of outputs on my previous project.

So this will totally free up my x4 injector 12v+ outputs on the relay board with x2 fused circuits (rated as far as 7.5 amps if using x4 injectors if I have read correctly). I have a Inovate wide band O2 sensor and EDIS-4 with coil that I need to power up. Can I utilize these outputs on the Relay board for the purpose of powering up my EDIS and O2 with readily available fuses? What is the limitations of the relay board as far as amperage and what sized fuses should I use for the Inovate and the EDIS?

I used a narrow band before so just need to know how much more the Wide Band O2 will take to run ( I fused the narrow heated with a 5 amp).

Will continue the search in the manual but there is alot of explanation but no 'put this here and it will work' details that I am after so far.

Thank you SOOO much for the help!

It's entirely reasonable to power everything except the MS itself off the fuel pump relay. Some actually recommend doing it that way, as it prevents the coils from powering up until the MS is ready to control them.

A 15A fuse works for the coil, and the wideband can use same 5A fuse as the narrow-band. The heater draws about 3A at startup, and the electronics are small change.