1985 GL1200 Limited ECU Replacement/Upgrade - Part 2

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Have had the Speeduino operating the engine for the past coupe of days with the new trigger wheel, working fairly well. As mentioned no more timing issues to date. Engine started quite well.

Was able to sit in the garage, not get smoked out, did not have the rancid smell from combustion.

Have tested the O2 sensor IAW with OEM instructions, controller appears to be good. Sensor has to be tested.

Operated the engine in the garage for about 1 1/2 hours this morning, varying the idle with the idle screw. Did this to take data logs, and adjust settings on the fly. The main settings being adjusted are in the VE and spark tables. I also adjusted the timing and checked with timing light. Not quite spot on, but very close. Viewed the AFR table and made some adjustments to it, but not many. Trying to get to a 1000 RPM idle.

Can view the trigger wheel log on the fly. I mentioned that I did not get the crank hole centred and had to file some of the teeth. The trigger log shows that the signal is not as steady as one would want, but is the best to date. May get another one and have the centre hole done by a shop.

The 1500 has a 12-1 crank trigger wheel, two versions a 4 and 6 degree. This should. not be an issue and it is an alternative.

When I did adjustments, made change, then listened. No change - went back to before change, change for the better left alone, change affected operation adversely went back to numbers before the change. When a change was good, went into the other tables and adjusted to suit. This is going to be an iterative process.

Going to research the dwell and injector characteristics to determine which ones can be changed on the fly and cannot, and what happens when this is done.

Have wiring harness to complete. ECU enclosure to be modified. Wiring between ECU and enclosure connector to be finalized and made permanent.

Getting to the interesting part.
Good morning. The collective on the Speeduino forum is educating me in the finer details of initial ECU tuning. lots of info wherever you look for carbs, but not so much for an FI system.

Today's lesson is regarding the VE table and how injector pulse width (PW) is affected. The settings in the VE table relate to a change in PW - this is for Speeduino, don't know about the Squirt family or others. The larger the number the longer the PW, conversely the lower the number the shorter the PW. Once the PW is set and the engine idles smoothly, the programmed voltage correction adjusts the PW to suit. Reducing/increasing the PW changes the time fuel is injected into the cylinder. At lower RPMs and idle, only takes one injector to cause an engine stumble or stall.

Injector dead time is affected in the lower RPMs as well, but is not adjusted like the PW. You have to set the dead time in the TS software.

Today's trial will be to try and dial in some better VE/spark and injector dead time, primarily VE (PW) and dead time settings.

Once I have these settings better selected, may look at the running dwell time.

Coming to an understanding of the intricacies of ECU programming.

Have started to finalize the ECU and enclosure fitting. Looking pretty good. Going to fit for but not with wiring that I can use later should I want to install an oil/fuel pressure sensor. Fitting a fuel pressure sensor would be beneficial because I can use TS to check the fuel system static and dynamic pressure instead of having to drain the fuel rails every time I want to connect the fuel pressure gauge.
Most are probably getting numb reading about this project, but it is progressing. I did anticipate it being a bit easier than it has been.

The inmates on the Speeduino forum have been very supportive, and I appreciate the following here. Trials and tribulations of going where no one has gone before - haven't read of someone doing a similar project such as an ECU replacement/upgrade on an '85 Limited Edition. Thinking a complete EFI conversion is probably easier to do and comprehend than a single component change such as this because you are looking for and using components that may have specifications included, or are somewhere to be found.

The project has been challenging and no matter what I have done, an envisioned result has not come to pass. "2+2" has to equal "4" and I was always keep coming up with "5".

My last post indicated a learning experience, have had another.

A project like this needs component specification(s). Specifications for new components are generally available, but not for older obsolete components. It is necessary to determine a way to find performance specifications on these older components.

This is where test equipment, doesn't have to be fancy or expensive, is your friend. Real time testing is important as well. You need information.

Have been having a timing issue since I started with the new ECU install. Getting closer to a resolution regarding this, but not out of the woods yet. The injector characteristics also affects timing.

With the new crank missing tooth trigger wheel, had a calculated trigger angle (TA) of 260 degrees, but settled on 278 degrees. This was noted on the other forum, but a lot going on and a comment can be hoisted in but not actioned right away.

The base TA number is dependent on where the missing tooth is located. With this engine, the sensor placement and the number of teeth the missing tooth is from the sensor determined the approximate TA. You still have to verify the TA with your setup.

Injector dead time specification for these Honda injectors is non-existent requires that correct settings be found by test and trial. Fortunately I had a scope trace of the installed injectors, and a fellow on the ECU site dissected the wave form. There was enough information on this scope trace to allow me to update the injector settings in Tuner Studio (TS). I was going down the proverbial rabbit hole, and have now got back on track. Was using an injector dead time of 0.7 to 0.8 ms. The scope trace indicated a dead time of approximately 1.5 ms - huge difference. Changed dead time setting to 1.5 ms and settled on 1.2 ms with engine operating. Changed the injector dead time to reflect 1.5 ms, kept the TA of 278, operated engine, not too bad, but not where I want it to be.

Timing, trigger angle (TA), was calculated with the new crank trigger wheel at approximately 260 degrees. I was operating the engine at 278, an advance of 18 degrees. This affects the idle, engine temperature - engine will operate hotter and engine temp will increase faster, and the ability to tune the engine.

Do some great troubleshooting at 3:00 AM, best ideas come to the fore. As I mentioned "2+2 has to equal 4 not 5". Changed TS settings for the injector dead time back to 1.5 ms, and the TA to 260 and started the engine. Have these settings adjusted to 1.2 ms and 265 respectively. Engine was idling fairly well at 1040/1060 this morning, more trials to be done.

New trial today, going back to the beginning, set TA at 260, and injector dead time at 1.5 ms. Adjust both for hopefully a good stable idle. The TA and injector dead time adjustment this morning went well. The timing was advanced 5 degrees. Going to trial by retarding the timing below 260 and adjust the injector dead time as well.

Next step will be to lock the timing at 15 degrees, the OEM setting, adjust the TA to ensure the timing is correct at 15 degrees advance.

Lots of good information out there about other inmate(s) trials and tribulations that take time to research. Have read a lot of forum threads and always learn something. The recommendations regarding a way ahead are given freely and with the intent to get your project to fruition. I never discard this advice, but do on an occasion deviate from them.

Getting closer to a resolution. More to follow.
What else is there to do in Canadian winter (unless you enjoy snow/ice sports)?
That's rather harsh!:LOL:Did enjoy outside sports in the winter when I lived where snow was. Enjoyed skiing, skating, hockey, snowmobiling, and of course coffee at Tim Horton's - Canadian tradition.

Took the front fairing off the bike last night. Need to tidy up the wiring that I have been playing with. Not able to do a good job when the fairing is on.

Going to change out the aftermarket coils that have no polarity markings. Honda service manual indicates that polarity is not a requirement. Always wondered about this. Went to the "oracle" for information (google). Consensus seems to be that polarity is not an issue, but coil output may be diminished by up to 25%, depending on who the author is. Have 2 sets of OEM coils and will install one in place. Thinking that a coil upgrade in the future may be a small project to do.

Project is turning into a CFI modernization project. I did mention years ago that this bike is my long term retirement project. Learning a lot from it.:cool::devilish:
Brief update. Going to revert back to the OEM CFI system for a bit. Have some things I want to take care of and I understand the OEM system best. Once I make sure all is good, will change back to the Speeduino. Have a lot more data available to me from the past weeks.

Have a new tune prepared, should make it easier to get the engine operating with the Speeduino. Have been learning/being schooled in the VE and spark table. Understand more about the VE table settings - increase the VE number to add fuel, decrease number to subtract fuel. This is done not by a global change of VE table cells, but to be done to a specific cell until you get the desired results. At this point you can start changing the setting in another adjacent cell until you get the desired results - repeat as necessary with other adjacent cells. It's very much a back and forth process.

Once you hopefully get a stable idle, vary the idle up or down and start the process again.

There is an auto-tune feature in TS that analysis the various tables and settings and can be used to adjust the table settings to optimize the tune.

After this you can start adjusting the spark settings to optimize the VE settings. Probably have to revisit the VE table and check the VE cell settings that have been adjusted.

Once the idle is at a stable RPM, you can then start to enable the various other functions, and TS settings. It is a lot to hoist in, but it will be worth it.
Looking into coil drivers/spark units. The units for the '85 CFI system require 12 VDC input and the new ECU setting is GOING HIGH. Most of the coil drivers I have found for this project require 5 VDC and when used with the new ECU the setting is GOING LOW.

Will be changing out the coil drivers when I start the next round of trials with the Speeduino with a new Bosch 211 unit that can operate 4 coils. It's about 3 by 2 inches Should be able to use an OEM connector to connect to the system:
Bosch 211 Coil Driver .jpeg
Wiring for the new install:
Bosch 211 Wiring.jpg
Will be looking for an alternate coil driver for use with the OEM CFI system.
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:
New Coil Driver Wiring.jpg

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 most newer and widely used spark igniters/coil drivers are a three wire. There are exceptions, but these are design exceptions for a specific application much like the Honda spark igniters. The 12 VDC input to the spark unit had me befuddled. Think I have the 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:
4 Wire Coil Driver.jpg
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 relationships between the various tables, and component settings. Lots to learn regarding this.

Bit of an update. Cheers
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Sent an email to Honda detailing my ECU project and requested any information it can release regarding the engineering, design, schematics not in the OEM service manuals, and component specs. Never know what Honda may release if anything.
Not that Honda would not admit to producing these motorcycles, Honda doesn't respond to emails. Fellow on the Speeduino forum indicated that Honda probably went to Denso with the design requirements and Denso put the package together. Sent an email to Denso, not expecting much but can't hurt.
Gee, I didn't realize Dendo had been around since the '40s. By the ND on the board in one of your photos, I would guess that Nippondenso (Denso since the '90s) did manufacture and probably stuffed the board. But I'd bet Honda supplied pre-programmed EPROMs. I'm sure that you have searched thoroughly, but goldwingfacts had some people that looked into this a couple decades ago (oregonwinger comes to mind). My SEi ran well, and the last I'd heard, about five owners after me was still happily riding. I had a spare (bad-blew fuses) ecu that I sent to Canada was it to you?
Don't expect a lot from Denso, but have to try.

The ECU from you has been donated to this project - 😔, if you need one let me know - will replace. Not to be a hoarder, but have three other operational ECUs - the original, spare I bought, plus the one that came with the 1200 carcass out of Ontario. The interesting part about these ECUs is that the engine operated the same regardless of which one I used - no fast idle, and a disgusting fuel smell on first start in the morning. Since you cannot change/vary any ECU parameter/setting, timing, fuel mixture and such cannot be changed and the issue will never go away. I expect that the 1800s will have issues as time goes on, but its FI system is more modern - is there an O2 sensor on the 1800?

A fellow I correspond with on the Facebook SE-i and Limited Edition forum, has an '85 Limited Edition, his second in about as many years, and he has a fuel mixture and idle issue. He wants to adjust the TPS to try and get rid of the issues but this has not been my experience.

I think I mentioned that Pim on the CX500 forum has been trying to fix/mod/change CX650 turbo CFI ECUs but has had little success. He is looking at the Speeduino, and other ECUs I suspect as replacement ECUs.

As I mentioned above, replacing/modernizing CFI components that are known to work with a specific ECU is a good consideration at the start of a project such as this. Trying to make an old design work with newer technology can be a stumbling block preventing real progress.

These Limited Edition and SE-i models are very robust and keep going, and going as you mention. It's when an issue occurs that people tend to think about bailing. Most owners will never attempt a project such as this, but as a retired old gentleman, can't leave this stone unturned. Should have an alternative part/component available just in case.

Long answer to your post.
Yesm the GL1800s have O2, knock, phase-of-the-moon. Newer ones even more. At least you don't have to acknowledge reading the safety card on every start as long as you own it.

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