[glavey]

We're getting close dudes and dudettes, we're getting close.

I got the gm map sensor installed without much trouble. One thing I did have to do was cut out key ways in the map sensor connector (pictured). As odd as it may be, it was cheaper to buy a clearly knock-off sensor + connector rather than just buying a connector. I bought the cheap senor/connector just for the connector, but it turns out there are different connectors for different sensors; mainly for 1 bar, 2 bar, and 3 bar sensors. The cheap sensor was a "3 bar" sensor and so was the connector. The genuine GM sensor was a 1 bar sensor. Nothing an xacto knife can't fix.

The "genuine gm" map sensor I bought did come in a acdelco box, but not the usual kind with the hologram on it. Either this is just an old-stock part and box, or the overseas sellers are getting more crafty at selling counterfeit parts. I have tested the sensor, and it does work and read as it should, so no worries thus far.

I attempted to make a holder/adapter for one of the gm temperature sensors, but failed miserably. I had a short piece of very thick gauge wire with two copper crimps on either side. I cut off the wire from the crimps and pounded the remaining bits of wire with a hammer and a punch in a vise. Then, I TRIED to re-open the two "jaws" that held the wire in place, but the copper was too work-hardened from being crimped, and I just mangled the whole thing. Oh well, I tried.

The temperature probe I jb welded on to a ring terminal worked out very well, and until I find a good way to mount the gm sensor somewhere to the engine, I'll be using it as the engine temperature sensor.

I also bought 5' of 3/16 and 5/16 fuel hose to use for all the low-pressure fuel runs, along with a fire extinguisher, gasoline-resistant sealant, various ratings of fuses, a bar clamp phone holder, and a 5/16 quick connect to 5/16 hose barb adapter. The fuel hoses are self-explanatory; I don't have an anti-gravity pump so I have to use hoses to move fuel to and from the gas tank. The fire extinguisher is, I hope, even more self-explanatory. I want this engine to remain an INTERNAL combustion engine. The fuel-resistant sealant is because when I took the fuel level sender off of the tank, I noticed that the rubber sealing washer was put in incorrectly and pinched (pictured). I don't know if that will cause a leak, but I am going the safe route and adding sealant. Fuses; so I only have the good kind of sparks. The phone holder is so I can connect the microsquirt to an app on android that gives me a choice of a few dashboards with most pertinent information easily read while I am riding. Don't worry, I have an old pre-dropped phone I am going to use for the dash display. The quick connect to hose barb is for connecting to the high-pressure side of the fuel pump. I mentioned in a previous post that the outlet on the fuel pump is supposed to be used with quick connect fittings, not with bare hose. The adapter is the necessary piece to go from the fuel pump to the high-pressure fuel hose. Note that they are called quick CONNECTS, not disconnects. You either need a special tool to disconnect these, or do what I did and buy one with a button you can press to release the adapter.

I was going to use the existing barb on the top of the fuel tank for the fuel return, but I just couldn't stop thinking that since the fuel hose going to the pump from the tank and from the pump back to the tank are the same size, if there were even a little bit of flow restriction on the return hose or the fittings, the fuel wouldn't be able to go back to the tank fast enough and cause higher-than-intended pressure on the high-side of the pump. Using a larger size hose along with larger fittings on the return route gives lots of room for high-flowing fuel. I chose a location on the tank that wouldn't be too far from the pump and not interfere with the plastic tank fairings. Mostly because of the inability to reach any other place in the tank, I chose to drill a hole near the rear of the tank, about an inch above where the tank fairing ends. Drilling the hole went without problem. I used a 1/8 npt female-female coupling, 1/8 npt male close nipple (yes, that is the correct term), a female-female 1/8 npt 90 degree elbow, and a 1/8 npt male to 5/16 hose barb adapter to make a clamping bulkhead fitting that hopefully along with jb weld will make for a leak-proof fuel tank return connection. I had to sand some of the paint off the tank to get a good bond with the jb weld. I ran out of black paint when I painted the license plate and exhaust brackets, so I had to use white touch-up paint (not pictured). The color mismatch doesn't really bother me, it is under the fairing so it won't be seem unless the bike is being serviced and the paint color wasn't chosen for aesthetic purposes, it's just what I had laying around.

I mounted and connected the gm temperature sensor that I am going to use for the intake air temperature. I chose the place I mentioned in the previous post, where the aliexpress CDI was installed. I had completely forgotten that there was an open-mesh air vent in the fairings right there. That means that the sensor will be getting at lest some airflow while riding at speed.

I connected the two "new" dash lights and they are now controlled by the ECU. The temperature light will come on if the engine/coolant sensor reads above 190F/~87C. The check engine light will come on when rpms are > 0 and the warmup fuel enrichment is >100% (100% is the calculated required fuel; 200% or 300% would be fuel added for a cold engine).

I still want to use the ignition advance inside the CDI box that came with the 190, but it is looking like almost every way I can think of using it is met with an problem that prevents me from using it.

Way 1. Go back to carb and CDI. Hahahah NOPE.

Way 2. Use the microsquirt in fuel-only mode and let the CDI control the spark timing. This one is the most promising, but there is one major problem; the crank VR sensor is the only way I have to sense the engine's position and speed. The CDI needs to use the sensor as its trigger, but the ECU also needs to use the senor to determine rpm. So both need the sensor's output, but the ECU cannot share the signal with the CDI; the CDI has a shared ground connection with the spark ground, power ground (circuitry to drive the CDI), and trigger signal (VR sensor) ground. So one lead from the VR sensor will be grounded (inside the CDI) to the same point that the spark plug and EVERY other power device grounds to. In the microsquirt manual, they warn about letting this very thing happen. It WILL cause bad interference with the rpm signal. Until I find a way to either split or isolate the VR sensor's signal, this option is no good.

Way 3. Give the microsquirt a completely flat ignition map, EVERYTHING set to 0, let the ECU output a signal exactly when it gets a signal from the VR sensor, and use that signal from the ECU to trigger the CDI to fire the spark plug. This would work, except the 190 CDI and every other CDI I have except for the one from aliexpress doesn't respond to logic-level inputs (usually 3.3v to 5v, low current) from the ECU. So unless I can find a way to drive the CDI from an ECU output, this option is not good.

Way 4. Extract the timing information from the 190 CDI and use it in the microsquirt ECU. The only "real" input the CDI has is the trigger from the crank and the only output it has is the ignition coil drive wire. The closer the trigger pulses from the crack are to each other, the faster the engine will be turning. If the engine is turning faster, it will in general, up to a point, need more spark advance, so the spark will happen closer to when the CDI gets its trigger input. By measuring the time between the input pulse (crank VR sensor) and the output pulse (ignition coil) at a given frequency, you can calculate what the spark advance will be for that given frequency.

In practice and as mentioned above, the CDI units do not respond to logic-level inputs. Also, the voltage signal from VR sensors goes positive and negative (above and below 0 volts). By themselves, the ECU and the arduino I was using to produce the frequencies, cannot drive a pin to below 0v. I do not have the necessary circuitry to make a negative-going signal, not to mention that the trigger circuitry inside the CDI might not even be driven by voltage, it maybe driven by current (as some of the earlier megasquirts were).

Unless I find a way to make the ECU and CDI cooperate and/or successfully extract the timing information from the CDI, I will have to use a pulled-out-of-my-ass, very conservative spark map on the ECU.

All that is left before I can do a test fire is to route the fuel hoses, take the bike outside, test/leak check all hoses, tank, pump, and fittings, and mount the exhaust.

Saturday, Sunday, and Monday are supposed to be above 60 degrees. I am cautiously and reservedly crapping my pants with anticipation and excrement. I mean excitement.