Finished the main relay wiring, had to run a power wire into the 125 harness for the same reason I did yesterday - wire gauge was too small. Confirmed the relay works as it should by testing everything except the horn. With as many of the lights turned on as I could, I measured roughly 500 mA through the lighting circuit. I don't know how much current a horn uses and I don't want to pop a fuse every time I honk at someone, budgeted another 500 mA for it. So at max that circuit should pull about 1 A, so I think a 2 A fuse will be sufficient.
I placed and semi-permanently mounted the aliexpress ecu and began running wires, crimping connectors, finding wiring routes, etc. I should only need to splice into/modify 6 wires on 3 connectors; power/ground for the fuel pump, injector, and o2 sensor heater.
I was looking online at vacuum-referenced fuel pressure regulators - youch! Unless you want to go with a REALLY cheap $15 regulator that has poor reviews, the cheapest ones start at around $100. The manual for the microsquirt does say that a vacuum-referenced regulator is and I quote, "Essential". I'm positive the people who designed the ECU and wrote the manual for it have done at least hundreds of EFI installs between all of them. This is my first one. I'm going to trust them.
I took a closer look at the little regulator/pump assy from the aliexpress kit. There are two holes on either side of the metal diaphragm housing and one on top. I think if I seal the two side holes shut and epoxy or JB weld a hose barb on the top one, I could turn this into a vacuum-referenced regulator! Even if it doesn't work, I'll still have the top hole open so it should still work as a fixed pressure regulator.
The two next big-ish things to do are to drill the holes in the 190 manifold for the TB, and get the bung welded on the exhaust. I'll definitely get the former done before the latter as I just have a puny little 80 A buzz box and all of my experience in welding adds up to about 10 crappy welds done on sheet steel. Also, there is a snow storm a-coming tonight and I expect to be slow-blowing a foot of snow tomorrow or the next day.
I'm also uploading a copy of the tune that was on the aliexpress ECU when I received it, I changed nothing on it. You can view it with the software posted
here, I'm nut sure if I have a high enough post count that external links won't look like spam. When you start the software for the first time, go to File -> Offline. The software is constantly looking for a connection to an ECU, slowing down the program and it will keep looking until you go click offline in the file menu.