1985 GL1200 Limited ECU Replacement/Upgrade

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Rednaxs60

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Have been looking into the differences between the MS units, as well as perusing the various threads to determine what will be the most economical way ahead, and which on could be tweaked for specific upgrades. The one upgrade I think would be beneficial would be coil-on-plug (COP) in place of the wasted spark system. This has been done on an 1100 with a Microsquirt unit. Keeping the bank-to-bank injection will be kept. I have also been perusing the various web sites and videos regarding this and the Microsquirt appears to be quite a powerhouse considering cost and features. It definitely has several advantages over the OEM ECU, but lets remember that the engineering and what Honda did back then is remarkable.

I have also read that the OEM injectors are oversize for the application. This is an interesting detail because the MS units allow you to tune the fuel injection and timing for better engine operation, and from what I can gather, compensate for this component.

The one question I have and have not been able to find the answer to is how the injector flow rate in cc (ml) per minute translates into what is required. The flow rate of the injectors for my bike is 65 ml/min (cc/min) at 40 PSI and this converts into approximately 6.2 lbs/hr. So with four of these, the flow rate in lbs/hr is 24.8 at 40 PSI. Don't know if I am correct, but it's the best I can come up with. Still searching for more info on this.

Thought I'd give a quick update.
 

Rednaxs60

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Just when I thought it was safe to go back into the water. Post over on the CX500-CX650 turbo forum because of similarities in the CFI system. Was introduced to the Speeduino system. Have done an initial look and this is a similar EMS. Reminds me of the DOS wars back in the '80s. Microsoft versus Digital Research DOS. DRDOS was a much better and a more fully functioned DOS, but Microsoft did a better PR and selling job, hence the demise of DRDOS. However, in this case, both Speeduino and Megasquirt products are evolving so it's anyone's guess how this is going to go. Will be going over the Speeduino literature and the forums regarding this. Uses TunerStudio as well. Always good to have options.
 

Rednaxs60

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Update required. Have done considerable review of the Megasquirt units and compared the functions to the OEM CFI system. Since I started this research, I was introduced to the Speeduino project. I have done a read in to this project, and the functionality of this Speeduino/Arduino system is quite good.

I will be comparing the two systems; however, I have to say the Speeduino project is intriguing, get to “tinker” along the way.

More to follow. Cheers
 

Rednaxs60

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Another update in my quest. Have been perusing the literature and videos regarding the Speeduino project as it would apply to my requirement. The more I delve into the Speeduino project, the more impressed I am with it. I have costed the Speeduino against the Microsquirt/Megasquirt units and the Speeduino product has more functionality and ability for future expansion/modifications for less cost. In this regard, I am going to direct my efforts towards the Speeduino unit.

I am feeling more confident in my understanding of the installed OEM components and how these interrelate. I will be making up test pigtails to plug into the various sensors to determine what the output/input signals are as installed. Should be of benefit down the road.

The Speeduino unit uses Tuner Studio the same way that the Megasquirt units do. A point in favour of the Speeduino unit is that the Speeduino project is still being actively developed whereas the Megasquirt project is not. Both products are touted as learning platforms, and as such, the onus is on the person using the product.

The Speeduino unit will account for the passive OEM IAC system. My research has indicated that it will do a good job of interfacing with the existing OEM wiring system so I will lose no existing functionality.

I have found a good YouTube video regarding using trigger wheels with the Speeduino (probably applies to the MS as well). The fellow doing the video makes a good case for doing a bench test of the new system before install. On my hit list.

Found another video with pearls of wisdom. This fellows thoughts are that one must READ, and learn everything possible - within reason I would think, about your existing system, or what the system components will be, the new system software and hardware and how you will connect the two. To me this is the preparation stage, and I have mentioned that the better the preparation phase, the better chance for success.

It was mentioned that I look into the injector" dead time". Apparently this is a useful number that has an impact on idle, low RPM and warm up. Another mystery to be solved.

I have re-read the CFI self-diagnostic system in the OEM Service Manual Supplement for my bike. Honda did a great job on this ECU programming.

For the MAP (PBR/PBL) sensors, if one fails the other operates the system as per normal. If both fail, ECU is programmed to use Ne-Oth map for both ignition and injection timing. Engine will operate normally with only one MAP sensor.

The cam (Gr/Gl) sensors are similar in that if one fails theECU uses the signal from the other sensor to operate the system as per normal. If both cam sensors fail, fuel injection and timing are stopped, time for a tow truck.

The crank (Ns) sensor fails, engine is dead.

The TPS sensor fails, Ne-Pb map is used to control fuel injection and ignition timing. If MAP (PB) sensors also fail, fuel discharge and ignition timing are both fixed - get home scenario.

Fuel injectors, if both fail - open circuit/shorted signal wire, fuel injection and ignition timing are both stopped. If a single injector has a short circuit, engine will operate, but an error code will be generated.

Interesting how Honda has the ECU configured to use an alternate signal for normal engine operation. The crank (Ns) sensor is a single install, but it can be installed either above or below the crank trigger and the engine operates as per normal. The upper and lower mounting position is exactly 180 degrees apart.

Honda did a good job of setting up the CFI system. Pleasantly surprised and get a better understanding of the CFI system each time I read the OEM manuals (for whatever reason).

More to follow. Cheers
 

joedrum

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Interesting stuff ....very interesting ..I’m still blown away on how complex it is to mimic a good carburetor .....i had a 1990 fuel injected mercury cougar with belt driven super charger v6 ...very bad ass car ...did some mods to it ..an uverdrive pulley and a super chip that change the fuel injection ..great car ..developer so much torque with also a inter cooler for super charger you couldn’t keep a transmission in very long before it would die ....the car would bark the tires shifting gears at 75 mph and how knows how fast it would go ...when I put the super chip in it bypassed the 145 mph limiter in it ...I once saw a video of one going 210mph on you tube ...with a couple of southern rednecks in the car .....I can tell you mine never missed a lick and would really plant your ass back in the seat when the air to air intercooler would reall show it’s stuff about 50mph on ....thiscar is one of the reasons on the hooch bike I went cold charge on the SCC set up and not heat the manifold ....big power in cold air induction ..hooch has proved to me I got lots of of power and no icing problem keeping the head heat out of the manifold set up ...
 

pidjones

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For finding the pulse lengths to the injectors, I suggest that your new scope may be the best source. I doubt Mother Honda has ever let that info out. You'll need to actually measure it. I do know that pulses and durrations were used for the onboard trip computer to calculate mileage.
 

Rednaxs60

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It was mentioned over on the Speeduino forum that I may have to operate a parallel EMS system in order to keep the travel computer (ETC) and LCD dash functioning. This is a good point and has made me delve more into the interrelationship between the ECU/LCD dash/ETC.

There must be a comparator circuit in the OEM ECU that checks for a signal to the various CFI components. If all is well the "FUEL SYSTEM" (check engine) light goes out - no more power to it, or no ground. The system allows for starting of the engine before this check is completed, done this many times. This indicates to me that this "comparator" circuit is not critical to the engine operation, but only indicates to the operator the state of the CFI system.

I am checking the wiring schematic and the OEM supplement to determine the relationships between the three units. The ETC does mention the "FUEL SYSTEM" light when troubleshooting a couple of issues.

The CFI system components that are being monitored are the MAP (PB) sensors, TPS, ECU, IAT, CLT, Injectors, crank (Ns), and cam (Gr/Gl) sensors. 11 components in all.

Been a while since I did any programming, but seems to me these are if/then type statements. With the newer technologies such as the Arduino, a small comparator circuit may be able to be put together to take care of this issue. It could also be as easy (nothing is easy or free) as a signal to the light from the new ECU.

If a comparator circuit was put together, and found to emulate the OEM ECU circuit, a small LED circuit could be added. This could be a numerical indication instead of the flashing lights that are presently used. Be a good diagnostic of the system should something go astray.

Looking at the dash/ECU/ETC schematics. The dash "FUEL SYSTEM" indicator light is connected to ECU-14 directly. It appears that the ECU grounds this indicator when it is lit and removes the ground when all is well. Removing the OEM ECU should only result in this light never coming on.

For the ETC. ETC-15 is connected to the wiring that supplies battery voltage input to the ECU, but is external of the ECU - good. ETC-5 is connected to 1/3 injector signal - external of the ECU as well - good.

I'm still thinking that there is a possibility that the system will work as normal when the ECU is changed; however, stranger things have happened.

The ETC takes care of the LCD dash digital tach. The dash tach indication can be displayed as digital and analogue, or just digital - switch is on the ETC. The ETC can switch the speed from Kms/hr to MPH - default for Canada is Kms/hr - nice feature when touring. The ETC fuel management circuits can also be changed from litres to USG.

Have also been looking into the injector "dead time", and how to get this information from the existing install. Have an AC/DC clamp meter - can read DC amps - and will look at this further.

As an aside, when Honda developed and designed the 10th anniversary fuel injected model, it forgot to include reverse. Don't know how Honda missed this considering the bevy of features that are included that newer GWs don't have to this day.

Keeping my thoughts focused.

Cheers
 

Rednaxs60

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After having done a comparison of the Megasquirt family and the Speeduino project, will be going with the Speeduino. Have ordered the unit, comes in at approximately $250.00 CDN assembled and delivered. Have found in the past that committing to a project only comes with some monetary outlay. Have Tuner Studio and Mega Logger, licence bought.

I have had a good look at the OEM wiring for the ECU, travel computer (ETC) and LCD dash. The LCD dash and ECU only have the "FUEL SYSTEM" light in common - from the self-diagnostic check. The ECU grounds this light on start, and removes the ground if all is well. With the new ECU, no ground, no light.

The ETC looks to use 1/3 injector pulse for the tach signal, and from this takes care of all the other machinations it does, including the LCD dash readouts.

I have done a pinout comparison and I'm thinking I will be able to install the new ECU and have the OEM system operate as per the OEM ECU.

I have also been thinking about the offset from this project. I intend to learn how the Arduino is programmed and in doing so, think that there will be other smaller projects that can be done using this as the platform. May not be for the bike, but for other things and just for giggles maybe.

Over the next couple of weeks will be doing some work on the bike, and during this time intend to install some inspection adapters (wiring) to get readings to use to tune the system through Tuner Studio. Have the information on the MAP sensors - installed newer Suzuki sensors. Want to find the injector latency, signal from the crank and cam VR sensors. The Speeduino unit has a 2 channel VR signal conditioner installed to convert the signal to a square wave. Look at the TPS signal, IAT and CLT as well.

The Speeduino will work with the passive OEM IAC system, space is at a premium on these FI models so this is good.

Doing engine work this fall and will install an O2 sensor boss in the exhaust at this time. Should be able to not use an O2 sensor, but it is recommended. Wonder how Honda did a CFI system in the '80s without one and had a good idle - go figure. O2 sensors are mostly a byproduct of the emission requirements, and from what I have read, used for idle only.

Intend to bench test this system using an 8/1 cam/crank trigger wheel arrangement.

Have given myself a 2 year window for this project. Lots to do and learn.

Cheers
 

Rednaxs60

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Thanks for watching/reading.

I just watched a video where the fellow switched from a Megasquirt unit to the Speeduino. Very good information, took notes. At the end of the video, he mentioned that he used a crank sensor with the Megasquirt, but installed a trigger wheel in the old distributor for the Speeduino. He then went and operated the engine on the Megasquirt, but at the same time had the Speeduino running in a bench test mode for lack of better vernacular, and tuned the Speeduino to match the car operation. Once he had the Speeduino set up, he did the swap.

I would expect that he used a bench model to simulate the coils and injectors, and would piggy back with the various other sensors.

The reason I mention this is that I have two crank sensors installed, exactly 180 degrees apart, use one and the second is a spare just in case so I don't have to remove the front end to replace a sensor. Since the engine will operate the same with either sensor, BTDT, I could use the second sensor as a signal to the Speeduino. There is also two cam sensors, only need to use one, and the same scenario, leave one hooked to the OEM ECU for engine operation, use the second for an input into the Speeduino for test/trial. Use the bench test model to imitate coil/injector loads.

This has merit, should not impact on the engine operation and aid in the transfer to the new ECU. Once the Speeduino is set up, use the same sensors as per the trial.

Interesting concept and would probably work with the Megasquirt as well.

Cheers
 

Rednaxs60

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Not much to report since my last update other than have been reading, and re-reading threads/literature, as well as watching YouTube videos both MS and Speeduino.

Have been looking into injector latency. Found this web site from my browsing: https://injector-rehab.com/shop/lag.html Looks like a starting point for the injector lag time is approximately 0.98

Have viewed a thread on the NGW forum regarding a conversion to cop units with a carb to EFI conversion by socrace.
Good mod, and I agree with everything he did: https://ngwclub.com/forum/viewtopic.php ... conversion The Speeduino can accommodate sequential ignition so this mod will be beneficial as I go forward. My only question is about the initial install with the existing OEM system wiring. I ask because I'm quite rusty with electronic circuitry.

The OEM system being waste spark has 3 ohm coils, no ballast resistor. The COP units I have looked at have a primary resistance of 0.660 ohms, secondary 6.1K ohms. Doing the parallel resistor calculation of 1/0.66 + 1/0.66 = 3.0 ohms. In my mind this would infer that I should be able to install these COP units in parallel and carry on as per normal as the resultant value overall is the same as the OEM Install.

Like how the cop install is. One issue I see is the fuel pressure test point on the right fuel rail is not available with the cop setup. Not a big issue, but would have to be considered.

Chime in, comments greatly appreciated. I'm with socrace in that some of these mods may not provide a noticeable difference such as the 12 VDC supply to the coils from the accessory fuse block that I did, but I know it has been done.

I am learning how to use a small drawing system - TinyCAD. Hope to get comfortable enough with it to do schematics.

Cheers
 

Rednaxs60

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Looked at a tutorial page regarding parallel resistor circuits and see my error. Since the two COP units are the same hooked in parallel would equate to a primary resistance of 0.330 ohms. Last time I read about this was 1981. The coil power is presently using 16 GA wire direct from the accessory fuse block.

I have started to look at the operation of the OEM system from a more technical perspective in that I have started to instrument the various sensors being used and seeing what the outputs are.

For instance I just finished with the PB (MAP) sensors. I married the two sides, and hooked up a vacuum gauge. The base vacuum at idle of approximately 1000 RPM (+/- 100) is 7 in of HG. The vacuum is max between 2100 and 2400 RPM at 12/12.5 in of HG. Here are pics of the readings:
Vacuum at Idle.jpg
Vacuum at 2400 RPM.jpg

I already have the pressure readings for these sensors so this is complete for the time being. It does raise a question in my mind as to what control mode - N-Alpha (some mention Alpha-N) or speed density is used and when, or if only one is used. Since there is no documentation on the ECU programming, have to learn what I can and make a decision from there. From my reading into the Speeduino system, an Alpha-N with MAP multiplier will probably be the start. Must remember there is no O2 sensor.

This tells me that the MAP sensor is probably not a factor above this RPM.

I did notice that I had to adjust the idle to accommodate the marrying of the cylinder bank vacuums, and that the engine RPM did not return to base idle as quickly as before I joined the two cylinder banks. I took the bike out for a road test and it appears to operate much the same as before except that the engine did not idle down as fast. Will be driving it with the cylinder banks joined together for a bit to see if there is any change. This will probably be a mute point with the new Speeduino since it will be using one MAP sensor, not two.

I'm also thinking that doing this investigative work may not be of any benefit to the new ECU, but at least I will have a better understanding of what is presently installed.

I will be doing the same for the other sensors over the next 6 months, primarily because I am getting my 1500 GW ready for a 5 week trip from Victoria BC to the Yukon/Alaska return.

I will be looking at the crank and cam wheels this week to determine how these are setup and correlate to what the Speeduino will need. As well I will be installing signal testing points for the other sensors as well.

May seem to be a bit disjointed, but I can assure you it will all come together.

Keep the comments/suggestions coming.
 

Rednaxs60

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Have been progressing my quest for an upgrade/replacement ECU. Have the bike in the garage so that I can put in additional wiring to do some signal tests, as well as some minor maintenance I have been wanting to do.

In advance of receiving the Speeduino ECU unit, I ordered a couple of Arduino Megas from Toronto and received them yesterday. This is the brains of the Speeduino ECU assembly:
Arduino Mega.JPG


Packaging was quite small, and I thought it was something else. Was surprised at the size of these units 4X2 inches, came with the CH chip but can work with that. Come a long way since the mid '80s. I remember my first computer, an IBM PCJr. Every time I started it, the message on the screen read IBM PCjr 128K the most powerful computer you will ever need.

Installed the firmware onto the Mega. Tried doing it through the Arduino software, but was getting an error message regarding "table H". Fiddled with this for a while then decided to use SpeedyLoader. Had to disable the virus software on my laptop, ESET, to use SpeedyLoader. Installed firmware without a hitch. Good start.

The assembled unit I have ordered has a Mega attached, will be interesting to see what it has.

Have been browsing the web regarding the Speeduino and how to set it up and use it. Every now and then have to visit the Megasquirt sites as well.

Found a site that has information regarding the air and coolant temp sensors and how to set them up to use with the software/hardware at this site: https://dtec.net.au/Tech%20Articles.htm Lots of good info.

It's a steep learning curve, but will be worth it.

Cheers
 

Rednaxs60

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Have been reading and watching videos - getting a better handle on this upgrade/replacement. Have the Dupont connectors ordered for bench testing and waiting patiently for the Speeduino unit.

The unit I ordered is assembled with a VR conditioner and step motor driver components installed. The board has an integral MAP sensor. It comes with the ULN2803 chip to be installed - use it for rad fan and fuel pump control. Here's the Speeduino board fully populated:
Speeduino Board 2.jpg
The board is only 10 cm by 10 cms. Pretty small compared to the OEM install.

Tried installing the ArduStim program in one of the Arduino Mega boards I have. This is used to provide inputs into the Speeduino to confirm that the input circuits are working. You do this with Tuner Studio up and running. Wasn't successful so will be working on getting this done.

Have been looking at the timing and Honda has me baffled so far. Been trying to determine #1 tooth using the Speeduino and Megasquirt info, but no joy. Have read the OEM supplement and it is a bit better. For the FI bike, Honda has three timing requirements, static, dynamic at idle, and dynamic with RPM increase. Here is a picture of the timing marks:
Timing Marks 2.jpg
Here's a PDF if the resolution is not so good:View attachment Timing Marks 2.pdf

I did look at the trigger wheel alignment regarding the three timing positions. For the static, initial timing adjustment, the tooth on the trigger wheel that aligns with the "T" timing mark lines up with the Ns sensor. When the timing mark is moved to the "F" timing mark for engine at idle, the tooth on the trigger wheel moves so that it is approximately 3 degrees before TDC. When the timing mark is moved out of the timing window, the tooth on the trigger wheel is approximately 10 to 12 degrees before TDC. Don't know if this makes sense, but reading this and looking at the timing marks may. I am going to do some degree readings and take a few more pics of what I am talking about.

Did some more work on this. Tried the methods in the Speeduino and Megasquirt documentation and no joy. Decided on a different strategy with the OEM timing marks. The "T" timing mark is a static measurement for determining #1 TDC. The "F" timing mark is for idle operation. Then the timing is changed from there. Took a small level and marked the alternator crank pulley at the 12, 3, 6 and 9 o'clock positions. This was to allow me to measure the crank degrees as per the timing marks. Here's a picture of the alternator crank pulley. You should be able to see the pencil marks I used:
Alt Pulley.jpg


Had the timing set for #1 TDC, then moved the timing to the "F" timing mark, took degree measurement with a protractor (very scientific) - refer to the timing mark diagram above. Angle measurement is approximately 13 degrees BTDC. After this the timing is advanced depending on the speed. This should be fairly accurate and give me a good starting position for the dwell angle.

I did look at the first tooth past the post and such, and got a degree reading of 135. Only have 8 teeth on the trigger wheel - 22 1/2 degree between each tooth. Missing something here, but I think looking at where the tooth is that passes the sensor and moving the timing marks to get a degree reading will be the way to go because I am keeping the OEM install.

I have added some connectors to take signal readings from the Gr/Gl, Ns and TPS sensors:
Wiring Sensor Taps.jpg
. More to follow on this.

Will need to get some readings from the air inlet and coolant temp sensors. Will do this fall when I do some engine work. As an aside, have ordered a set of rings for the old girl. Could probably reuse the OEM rings, but call me old school, when cylinders are honed should put in new rings.
 

Rednaxs60

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Been doing some more homework. Hooked up test wires and used the small scope I bought, the DSO138. The Ns - crank sensor trace is:
NS Sensor Signal.jpg
It's a sine wave so will need to use a signal conditioner to make it a square wave. The Gr/Gl signals are the same - sine wave, but comes through quite a bit less, only one pulse showed up:
Gr Sensor Signal.jpg
Need to look into this more.

Checked the timing with my Father's old Snap On unit:
Dad Timing Light.jpg
Timing Light 2.jpg
The engine has a 14/15 degree BTDC at operating temp. The staring advance is approximately 25 degrees BTDC. Good starting point.

More to follow.
 

Rednaxs60

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Having my brother send me my father's tach-dwell meter to get the dwell numbers. Had to do a little more research and you are not able to convert the degrees BTDC into dwell time.

Also need to determine spark plug burn time. Going to get a Secondary Ignition Capacitive Auto Pickup Probe for the small oscilloscope to get this info.

So much to do. Learning a lot about this CFI system and the intricacies of changing out an OEM product.

Cheers
 

joedrum

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Wow again what a project ...your the man here ...never seen anyone drive in so good in the FI oldwing...seems most ditch everything from original and end up with nothing in the end ...keep plugging away
 
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