NGWClub®, Inc.

Time for coffee, it is "whew". There's a lot to hoist in with regards to an ECU. Trying to decipher the information and why things are happening is keeping the brain box engaged.

A short update. Have mentioned that I have had engine starting issues, timing lock and backfires, never a consistent start, and hard on the engine. Made a new wiring harness from an old spare, no noticeable change. Ordered a 36-1 crank trigger wheel, received it this week. Drilled/filed the centre hole to fit the crank. Bit off centre, had to fit the teeth to the sensor. Have a sensor tooth gap of 0.028" to 0.048".Put the front back on, rad and such.

Used the new wiring harness, no start. Tuner Studio (TS) indicating no sync. Changed over to the OEM wiring harness, no joy. Retraced my steps. Had installed ferrite toroids on input signal wires, removed the one from the crank sensor input - no joy. Thought about the wiring may be backwards, switched the signal and common wires and have engine start.

Engine started quite nicely, no timing lock or backfiring. Thinking it isn't catching all four cylinders on start - will investigate.

Adjusted the engine trigger timing in TS, and settings in VE and spark tables. Idling around 1200 not too bad.

Need to connect the O2 sensor and start tuning with it connected. Have had it set to no sensor for the initial start. It is recommended to disable all functions not required for initial starting, then enable these functions one at a time and tune to suit.

Engine start in the morning will be telling. Here's hoping and fingers crossed. Should be able to get into the meat of this ECU and get it ready for the road.

Have sourced and known of alternate parts/components for the CFI system except for the OEM ECU. This was the main premise for this project. Thinking I now have a suitable alternative for the OEM ECU.

Cheers

Another brief update. The 36-1 crank trigger wheel came in. Had to drill and file the crank hole. After all the grief with engine timing decided to bite the bullet and install the new crank trigger wheel and not use a dual wheel trigger system. Anot her fellow on the Speeduino forum had issues with getting the Honda dual wheel system to work. Sometimes it's better to go with a proven conversion such as the 36-1 trigger wheel instead of trying to make an existing system component(s) work. These component(s) work well within the system the components were designed for, but maybe not outside this.

Install of the new trigger wheel, and disconnect of the cam sensors got rid of the sync issue. Had a small wiring change with the crank sensor to fix, swapped the wires around.

Engine spun up, no timing lock or backfiring. Idled best ever. Adjusted the timing and several settings in the VE and spark tables.

Did another trial today, mostly a feel good trial, some setting changes. Operated the engine for approximately 1 1/2 hours varying the idle. Pleased with the results. Stop/start was good. Have the VE and spark tables adjusted so that there was little exhaust smell out the back end, and I did not fill the garage with excess exhaust fumes.

The O2 sensor is not working properly. Did a voltage/gauge reading test of the controller - was good. Have the sensor to do. Hopefully the sensor is good, but if not will be going back to 14point7. Using the Spartan 3 Lite with ADV/LSU sensor.

Working on the harness wiring. Will be adding wiring for fuel and oil sensors - fit for but not with at this time. Fuel pressure readings in Tuner Studio would be beneficial, wouldn't have to drain the fuel rails every time I want to test fuel system pressure. Can also have the Speeduino control the rad fan. Good feature especially when you do a lot of city/start-stop riding, have fan come on at a lower temp.

Have a stumble/stall at lower RPM. Trying to get the engine settled on a 1000 RPM idle. Bit more work to do regarding this. Need to have this put to bed before moving on to road trials.

Have considered the issue to be the TPS - inexpensive key component that has very poor QA/QC, spark igniters - have a spare set of original spark igniters, fuel system - fuel pump, will test fuel system pressure, injectors - 284 cc. I have a set of aftermarket injectors for a 1986 Prelude. Think these are approximately 240 cc. Bit more work to do.

Feeling good about the progress so far. It's a daunting project without doing a full conversion.

Have had a small setback. Working on resolving it. Brief update.

Have wired up the new coil driver, and connected it to the OEM wiring harness for use. Took the OEM spark units out as well as some non-essential vacuum hose.

Wiring diagram for new Bosch 211 coil driver: Should work nicely.

Did more research into the OEM spark unit because the 12 VDC power connection to the spark units, these are a four wire spark unit, was befuddling me considering that more newer and widely used spark igniters/coil drivers are generally a three wire. There are exceptions such as the seven and eight pin HEI coil drivers, but these are design exceptions for a specific application much like the Honda spark igniters; however, these exceptions are being used for EFI conversions. Lots of install information available regarding these.

Think I have an answer.

The OEM spark unit appears to use a Darlington Pair transistor design. This is where two transistors are paired together to increase the final output. The triggering and secondary transistor can share the same 12 VDC supply - in this case it would be from the coil, but can be separated. This schematic depicts a Darlington Pair transistor circuit that has a separate 12 VDC connection for the T1 transistor from the electrical system, and the T2 transistor from the coil: You can see that that "T1" is triggered by an external signal, in the case of a coil driver in an EFI system, the ECU. The output from "T1" triggers the second transistor in the circuit allowing the coil to charge. I think this schematic is representative of what Honda has designed, but without the actual schematic it is a best guess.

The transistors represented are the NPN "sinking" transistor. There is a PNP transistor. The basic difference is that with the NPN transistor, the load, in this case the coil, is upstream of the transistor - look at the direction arrow. The PNP "sourcing" transistor differs in that the load in question is downstream of the PNP transistor.

This project has turned into a very good learning experience.

The other aspect of this project that is surfacing is that this project is becoming a two-part project. The first part is the primary purpose of replacing/upgrading the OEM ECU. The second part is a modernization of the CFI system components.

The modernization aspect has been mentioned before, but that was not the initial intent. Hindsight being beneficial after the fact, a modernization of the OEM CFI system components could have been part of the planning/research stage.

The challenge with this is that if you keep the OEM ECU, you could have issues with newer, more modern components because these new components have different design specs. Without knowing exactly what the CFI system components design parameters were, you are doing a test and trial modernization.

Doing an EM CFI modernization with a new ECU is simpler. Replacement components have generally been tested and the ECU settings finalized.

Replacing the OEM spark units with newer coil drivers that have been used with the Speeduino, and the programming settings have been determined, increase the odds of a successful conclusion to the project. This is the same for the OEM dual wheel timing trigger system. Changing out to a crank missing tooth timing trigger configuration is the same.

Replacing the injectors, be the injectors low impedance (need resistors to keep circuit current minimized), or high impedance injectors (no need for additional resistors to keep circuit current low) may be a luxury, but the injector specifications, specifically injector dead time may be available. Keeping the OEM injectors will require an iterative process to "dial" in these injectors.

The TPS, IAT and CLT sensors can be used without change, as can the crank (Ns) variable reluctance (VR) sensor.

Using the crank missing tooth trigger wheel allows you to disconnect the cam sensors. A dual wheel timing trigger configuration is only required if you are going to do sequential injector timing/firing. I have read that for a recreational engine, there are some benefits for sequential injector firing regarding emissions in the lower engine RPM/idling range, but not so much in the cruising/upper engine operating range. Another consideration is the wiring has to be changed to suit.

The PB (MAP) sensors can be used, one for the MAP input, the other for a real time barometric sensor. You can get the new ECIU fitted with a MAP sensor. If this on board MAP sensor is not fitted, you will have to do some work to connect the OEM external MAP sensor for both the MAP and Baro inputs. If you choose two not use a Baro sensor, the ECU uses the barometric pressure that is sensed by the MAP sensor for all engine operations. The only time this will change is when you turn the engine OFF and restart. The new barometric pressure reading taken at the place you started the engine will be used.

I will be using the on board MAP sensor and wiring in one of the OEM MAP sensors for a real time barometric sensor.

The issue with components is hopefully someone has gone before, and an alternative component has been used successfully. The second issue that is more challenging is understanding the ECU relationships between the various tables, and component settings. Lots to learn regarding this.

Bit of an update. Cheers

… sure …

Gord(nodding and smiling)Jones

More progress. Have been working on the install. Did a sequential fuel install of the injectors (have four injector channels), worked first time.

Installed COP units, made one of the COP units into a #1 cylinder timing COP. Needed to extend the plug wire to use the timing light on. Checked timing and no change. Operating in sequential mode as are the injectors. Forgot to take off the fixed timing, engine did not like. Started quite well. Did this because socrace did.

Was reading the Speeduino Wiki, the bible for the Speeduino. It was recommended in the section on ignition to convert from older OEM style ignition design to a more modern COP, or CNP install. This is recommended to remove the separate ignition modules, and improve system efficiency. You can connect these up in a waste spark configuration, but the Speeduino interface board I am using has 4 ignition channels so I have used them. Changed out the Mitsubishi 3 channel coil driver for a Bosch 211 4 channel coil driver. These COP units fit a Ford F-150. Dwell, cranking and running is at 1.5 ms, with a spark duration of 2.0. Seems to work well.

Now for the VE and spark tables, clean up the wiring. Will not be able to finalize the COP install until I get the front fairing back on. Probably going to be a coil-near-plug install. Have to work around the CFI covers as well.

Quick update. The sequential ignition and fuel injection is working well. The Speeduino interface board can accommodate 4 ignition and fuel injector channels.

Reduced the Required Fuel (RF) to 5.8 from 6.4. Engine operated a bit leaner, 14 AFR instead of 13 AFR. Working on adjusting the VE and spark tables.

Reviewing the various GW and other forum threads for EFI conversions. It was more prevalent back in 2010 or so than now. Lots of work, and not inexpensive even if you are starting with an existing EFI system such as that on the '85/'86 GW FI models. Trying to make an older EFI "package" deal work with modern components is a challenge.

Made a baro circuit for the final install: Going to make the COP unit wiring permanent because it is working well.

For socrace, his install was my inspiration. Only the second sequential fuel and ignition GW 1200 that I know of. Picture of the left side COP units. Working on securing these units, have to modify the CFI cover brackets. It can be done: Experimenting with paired and sequential to determine why the dash RPM indication does not work, did at the start of this project. The signal for the tach comes from cylinders 1/3 fuel injector and goes to the travel computer then to the dash.

Had some time to make some progress. Front brakes needed to be serviced, front wheel turns freely. Will still need a good maintenance period before the summer.

Good news, bike is out of the garage: Will have to wait until after Boxing Day to insure the bike. Did some small runs up the driveway in gear. Gives me some time to get the tablet mounted and maybe look at the mess under the seat. A project of this type can take up any extra room available.

Have a dash tach issue. Think that there is only one injector pulse to the travel computer for the dash tach. Have to investigate.

Should be starting road trials in the New Year.

Lots has been learned regarding this project. A key issue is patience. This type of project is not a start, finish and go in a very short time frame. Slow and steady wins this race.

I had envisioned a quick resolution to this project, but this impeded progress. Started with the premise that I would use all the OEM CFI components, and be able to easily revert back to the original OEM setup. The project has morphed into as complete an upgrade as I think possible.

The fuel system has been upgraded. The CFI system has sequential ignition and fuel. COP units have been fitted. The OEM spark units have been replaced with a single 4-channel coil driver. The low impedance fuel injector resistor pack has been replaced with individual fuel injector circuit resistors - 6 ohm each. The original OEM wiring harness has been used and available wiring to the new ECU has been used to minimize additional wiring runs. The VR crank and camshaft sensors have been replace with Hall Effect sensors. These sensors use the existing PB sensor wiring to connect to the new ECU. The O2 sensor is using the original Ns crankshaft sensor wiring to connect.

Using the existing spark unit connections for number 1 and 3 COP units. Have had to run new wiring for cylinders 2 and 4 COP units. Engine firing is 1/3/2/4.

Have kept the original crank and camshaft trigger wheels. The 8/1 dual wheel system works well with the Hall Effect sensors. Could have kept the crankshaft Ns VR sensor but removing it allowed me to not use a VR signal conditioner. The Speeduino interface board is populated with a 1K pull up resistor for the new Hall Effect sensors.

Took a bit of time and effort to ensure the plastics and various covers fitted with the new component additions.

The GW has been off the road for a bit, but glad I tackled this project. Merry Xmas and have a safe and prosperous New Year. Cheers

Have been progressing the project. Have done several road trials and reviewed the data logs. Had a hiccup, starter needed a refresh, and all is well now. Hoping the weather starts to cooperate. Have started using KiCad for wiring schematics and such. Have tried many of these programs and have let myself get frustrated with these, then into the bin with them. Going to make myself conquer KiCad. Have a preliminary wiring schematic done, more to do with it: Will be doing a reflections/lessons learned, and what I would recommend for a way ahead. This type of project can be as simple or as complicated as you would like it to be. It must be remembered that this is about replacing the ECU on an '85 GW Limited Edition FI model, but there is a lot that can be ported over to a new EFI install.

Great that you are still progressing with the upgrade. Very interested in the tuning progress so keep us updated

Are you still thinking of an EFI conversion?

Quick update. Road trials are progressing and not too bad a result so far. Have a lot to learn about road tuning, but will prevail. The sequential fuel and ignition is working well. Concentrating on the VA and spark tables. In the garage for some maintenance, front tire keeps loosing air. Checked the timing once more because the rad is off and I can see the engine timing pointer better. Checked the idle timing against the "F1" flywheel mark and it appears to be in the 12 degree range.

Have been using KiCad for the schematic(s). Have used many programs/apps and when I got frustrated, into the bin with it. Can't keep doing this so KiCad is the scape goat, and I'm getting used to it. Have an overall schematic done, and using KiCad to catch up on other mods I have done: Cheers

Yeah still into it.
But will hold of until at least next year since I'm already modifying my bike quite a lot.
I do learn from all your posts as you progress on your conversion.

I did a few mods before this one, side stand safety switch, external alt mod, and manual rad fan switch.