'85/'86 100 GW CFI ECU PnP Replacement

There's lots to consider with these older FI models. Obsolescence, can the owner change the engine tune (NOT), and do you keep these FI models on the road. I submit that other than the FI system being an issue, these bikes will last for a long time.

This thread is specific to the '85/'86 1200 FI models. There is another thread on a PnP for carb models.

I think about this issue whenever I work on my '85 FI model.

I have modified/modernized the CFI system of my bike. I have done extensive changes and will never be reverting back to the original CFI configuration. This in itself requires a lot of extra non-bike work such as a good set of schematics representing the change(s).

Going to end this first post and continue with a second.

Cheers

I was looking at the FI system as installed by the OEM, and thought about what is the minimum change requirement.

The CFI system in its entirety minus the Gr/Gl sensors, PB sensors, and the 8 tooth crank trigger wheel will not be needed.

The 8 tooth crank trigger wheel will be replaced with a 36-1 75 mm missing tooth trigger wheel.
A wide band O2 sensor will need to be installed.
The Gr/Gl sensors will be disconnected at the connector under the shelter.
PB sensors will not be required, there should be a MAP sensor on the Speeduino interface board that will be used by the new ECU.
The spark units (coil drivers) will be used.
TPS is useable.
Injectors and coils in a wasted spark and paired injectors profile will be used.
Inlet air temperature (IAT) and coolant temperature (CLT) sensors will be used as well.
Fuel system will be used as installed.

Tuning issues - quite a few mainly because there is no component data available. Experimentation will be required to "dial" in each component, one at a time.

The CFI injectors are approximately 284 cc/min, or 315 cc/min depending on the service shop. The fuel system operates at approximately 28 to 32 PSI and because of this, the injector size used in the tuning software will have to be derated from the 284/315 cc/min to suit. This is because fuel injectors are tested at 42 PSI (3 bar) in a service shop.

Tuning and analytic software will need to be purchased, recommend licensed versions recommended.

Recommended tuning parameters/settings will be posted as a starting point only. There is no free lunch so to speak, and research on an owner's part will be required.

VE (fuel), spark (ignition timing) and AFR tables will be posted to assist in getting going, but it must be remembered these will be a starting point only and will need to be recalibrated for the application.

Engine timing will need to be addressed. Unlike the OEM timing specifications where "T1" is used to align the crank and camshafts, and "F1" is used for base/idle timing, owner(s) will need to brush up on engine timing using a timing light. An engine timing mod in the timing belt area will be discussed. Trying to look at oil soaked crank marks is not an easy task.

There will be some wiring changes, similar to the owners who have added electronic ignition systems to their bikes.

A wiring pinout will be made available based on the Speeduino v0.4.4 interface board.

Cheers

An issue with a CFI ECU replacement project is how much do you do and what can result from a lot of changes.

An owner will want to maintain as many, if not all, existing features/functions, specifically when thinking about the travel computer.

I found that keeping the initial ECU and CFI component change to a minimum resulted in no loss of any original features/functions, this includes the dash tach function. This signal is used by the travel computer for the fuel and travel management features. Venturing forth and changing the initial wasted spark and paired fuel injector profile can result in the loss of the correct signal from the CFI system to the travel computer resulting in a loss of of the tach feature, BTDT.

More to follow, Cheers.

Way over my head but interesting reading.

Forgot to mention that it's quiet on the various forums, and my GW FI model keeps the inquisitive side going.

Motorhead - if it's something you are interested in never way over one's head, never know when or if this information may be needed.

Cheers

Have given more thought towards this topic. I will be choosing a Speeduino interface board, probably the Speeduino v0.4.4, and doing a post or posts on what I would do considering the learning process I have gone through. You could say it's a how to, but as always, I take no responsibility if someone were to try the change. It would be a good upgrade though.

I have decided to pick a Speeduino interface board, probably the v0.4.4, and do a post/posts on the process. This will not be a complete "How To", but provide more info and considerations.

To start, this board forms the basis for many Speeduino clone interface boards. The sister board containing the microprocessor, Arduino Mega 2560, attaches to the underside of the v0.4.4 interface board. Overall size is approximately 4" by 4" by 1.25" with the Arduino Mega attached.

This Speeduino interface board with the Arduino attached will support an EFI system up to sequential fuel and ignition. Can be configured for nitrous, variable valve timing, boost control, a tach output, and other niceties.

The board generally comes with an integral MAP sensor, an MPX4250AP, works well.

There is a header for a stepper driver (idle air) not required.

There is a header for a VR conditioner - MAX9926. This is needed if you intend to use the crank VR sensor because the VR sensor signal is a sine wave and the Speeduino needs a digital square wave signal.

There is a Proto area that a can be used to do small circuits, or install the ULN2803 Chip this chip takes the place of dedicated pins for items such as fuel pump relay, rad fan, and such.

There is no onboard barometric sensor, but you can install a remote sensor with the appropriate circuitry.

I decided on this board when I first started to look into this project for my bike.

I mention that the Speeduino v0.4.4 board is an interface board because it connects the Arduino Mega with the CFI system - intermediary.

The next item needed is a new crank trigger wheel if you are not going to use the camshaft for a second rotational input.

The crank trigger wheel that is recommended is a 75 mm 36-1 missing tooth trigger wheel that fits where the 8 tooth crank trigger wheel is located.

You can use this as a stand-alone trigger wheel, do not need a cam input.

You need to purchase a wide band O2 sensor, I use one from 14point7.com. Need this sensor to do engine tuning.

The cam sensors as installed cannot be used. Aftermarket ECUs only use one cam sensor. The VR sensors used do not provide a consistent signal to the ECU because of the half-crank speed. Need to upgrade to a Hall Effect sensor if you intend to use a cam sensor.

You do not need to use a crank and cam sensor at the start; however, you may want to consider using a crank and cam sensor at the start. A single crank sensor input will start and operate the engine, but the ECU is always "guessing" the exact engine phase, where is/are the exact position of cylinder TDCs. With a cam input, the engine phase - TDCs, is defined.

If you are to use a cam input, you will need to use a Hall Effect sensor for the cam input. You will also be able to keep the 8 tooth crank trigger wheel, no need to change.

Mentioned the crank VR sensor can be used. You will be able to use the crank VR sensor and a cam Hall Effect sensor together by properly configuring the VR conditioning board to suit. You may want to upgrade the crank VR sensor to a Hall Effect sensor, eliminating the need for a VR conditioning board all together.

Next post will be on some of the wiring changes need to get started.

Wiring and Recommended New Items

This is for a wasted spark/paired fuel injector profile.

Starting with new items:

75 mm 36-1 crank trigger wheel – approximately $70.00 CDN
2 – Cherry Hall Effect sensors – GS100701 – approximately $38.00 USD – Qty 2
WBO2 sensor – 14point 7 – approximately $183.00 USD
Speeduino ECU with Arduino – approximately $150.00 USD – without case or connector
944 ECU Connector 35 Pin Bosch – approximately $35.00 USD
Miscellaneous mounting hardware - $50.00 CDN
Tuning software – Tuner Studio and MegalogViewer (licensed versions) – approximately $110.00 USD

Hall Effect sensors have a power, ground and signal wire. Should you choose to install the Hall Effect sensors in lieu of the VR crank and camshaft sensors (one for crank – one for camshaft) you can connect these sensors to the PB sensor wiring harness connectors. There will be no need to remove the crank and camshaft trigger wheels, can be utilized as is in a dual wheel profile. Recommend because there will be no requirement for a VR signal conditioner, and you will use the crank VR sensor wiring for the WBO2 connection to the ECU.

Install the Hall Effect sensors using 1” aluminum angle.

PB sensors need to be disconnected and can be removed.

Disconnect and remove the OEM cam shaft VR sensors, and disconnect from the connector from the OEM wiring harness.

The WBO2 sensor can be connected to the now redundant crank VR sensor wiring connector.

Engine vacuum connections can be used and recommend routing these to a vacuum mixing block, then one hose to the ECU. The vacuum mixing block can be ready made, approximately $35.00 CDN on Amazon, or you can make your own.

The 35-pin connector is used to connect the OEM wiring harness and the ECU wiring.

Recommend using a multimeter to prove that the wiring is correct.

All other CFI component wiring connections can be used as is.

Wiring Pinout



Notes:

1. Use OEM pin 1 or 19 for ECU main 12V power connected to separate position on Speeduino board.
2. Main ground connected to separate position on Speeduino board.
3. OEM Pin 30 not used
4. OEM Pin 14 not used
5. Unused Speeduino Ground Pins 10/23 to be tied into main ECU ground
6. This ECU pinout chart is based on using the crank (Ns) VR sensor, and no cam sensor. Changing to cam and crank Hall Effect sensors will change pinout chart. PB sensor connectors will be used for cam and crank Hall Effect sensors.
7. Continuity of ECU ground plane to be checked for no continuity. If continuity between main ECU ground and sensor ground, need to troubleshoot and ensure no continuity between grounds.

This is the first install of the Speeduino ECU. Basic functions necessary to operate the engine. Not many wires needed. Only the dash FUEL System indicator and self diagnostic feature were not available.

Started a Word document detailing a CFI ECU replacement project. It will take me a few days to complete. Includes pictures of changes, basic engine tuning settings to get you going and wiring schematics for the options. This document is not meant as an EFI tutorial, or how to use the engine tuning and diagnostic software programs. Hopefully it will be a thought provoking document.
If there are specifics regarding a CFI ECU replacement project, please post and will answer if I can.

More to follow.

Wow, this is deep.
Not offering criticism of any sort, just thinking out loud: if I were going through the trouble of re-engineering the engine management system it would be for a turbo system as what will be the end result on the street otherwise? The stock cams can only deliver so much.

Rednaxs60 said:

Started a Word document detailing a CFI ECU replacement project. It will take me a few days to complete. Includes pictures of changes, basic engine tuning settings to get you going and wiring schematics for the options. This document is not meant as an EFI tutorial, or how to use the engine tuning and diagnostic software programs. Hopefully it will be a thought provoking document.
If there are specifics regarding a CFI ECU replacement project, please post and will answer if I can.

More to follow.

Click to expand...

Ive just got an older Motec M48, that's brand new they are pretty bullet proof , just slower to set up DOS program , still run speed density. cheers.

Motörhead said:

Wow, this is deep.
Not offering criticism of any sort, just thinking out loud: if I were going through the trouble of re-engineering the engine management system it would be for a turbo system as what will be the end result on the street otherwise? The stock cams can only deliver so much.

Click to expand...

Not doing this project or this document to get performance gains, will be nice if and when this happens. The purpose is to have an alternative for the OEM CFI ECU that can be installed without too much inconvenience, something like the electronic ignition mods for the older carb GW models. Without an ECU, these FI models become a lawn ornament, boat anchor, parts supply, or a candidate for a conversion to carbs. Carb models have issues as well.

There's a person on Facebook that has a new OEM ECU and wants $1000.00 for it. Still an old ECU, and operating an old EFI system. Cannot change/alter the OEM engine program, so if anything starts to happen, components start to degrade and such, you're still "hooped". What's the shelf life for electronic components?

I would think that installing a turbo on an '85/'86 GW FI model would be a huge challenge. Where would it be installed? The project would be a complete reconfiguration. My project did not start out to be a re-engineering of the CFI system, just a humble ECU upgrade. It has morphed into a complete modernization of the CFI system, mostly because I could, and I kept upgrading because the project was not progressing as I thought it should. The old story that if something is not working, maybe if I do this it will. It was a lack of understanding of an EFI system and what to do.

Trundling on, slow and hopefully sure! Need a good hobby in retirement and this is the one I've picked! Cheers

Rednaxs60 said:

"There's a person on Facebook that has a new OEM ECU and wants $1000.00 for it."

Click to expand...

I get it now and also the sheer fun of inventing & tinkering.
Here's a turbo GL1200

Read about this one, not a lot of real estate for the turbo.

Have finished a basic ECU replacement install document (attached) for those who need some before bedtime reading and suffer from insomnia.

Cheers

Rednaxs60 said:

Read about this one, not a lot of real estate for the turbo.

Have finished a basic ECU replacement install document (attached) for those who need some before bedtime reading and suffer from insomnia.

Cheers

Click to expand...

Very good read.
How are you going to make the key for the new crank trigger wheel? I think it would have been a bit easier if the key was inverted like on the cam pulley wheels.

theailer said:

Very good read.
How are you going to make the key for the new crank trigger wheel? I think it would have been a bit easier if the key was inverted like on the cam pulley wheels.

Click to expand...

This picture is an example of the 36-1 crank trigger wheel centre. Think this is what you mean. Use a small 1/8" keyway to suit:

Have started amending the PDF document based on queries. All queries will be reviewed and if required, I will edit the original document.

Rednaxs60 said:

This picture is an example of the 36-1 crank trigger wheel centre. Think this is what you mean. Use a small 1/8" keyway to suit:

View attachment 50814

Click to expand...

Yeah but isn’t the crank wheel key inverted which would make it a pita to drill?
I’m not in the trigger wheel manufacturing business so I might be missing some info

theailer said:

Yeah but isn’t the crank wheel key inverted which would make it a pita to drill?
I’m not in the trigger wheel manufacturing business so I might be missing some info
View attachment 50815

Click to expand...

Interesting pic. Looks like it's cracked and ready to throw a tooth.