1985 Limited Edition and 1986 SE-i Fuel Injection Motorcycles

[Rednaxs60]

Fuel system design will be a challenge, routing of fuel hoses, filters – before and after fuel pump, which high pressure fuel pump to use, fuel rails, fuel injector connections.

There’s no lack of things to consider.

High pressure fuel pump – just about any fuel pump that can provide up to 70 PSI fuel pressure will suffice. Recommend the fuel pump have an internal non-return valve to maintain fuel system pressure when engine is not operating.

Placement of fuel filters will be more challenging, but a necessary requirement. There are many products available for fuel hoses, complete with fittings. Fuel hoses with an inside dimension (ID) of ¼” should be sufficient. Some research will be needed for this.

Fuel system rails need to be fitted and the fuel injectors need to be connected if ITBs are not used.

Fuel injector holders and placement of these fuel injector(s) connectors are another challenging issue.

The fuel system will take a good amount of thought.

Fuel pump shut off sensor when the bike is laid on its side is, in my mind, a necessary component. This sensor shuts off power to the fuel pump and with a new EFI conversion to shut off power to the EFI system.

Throttle position sensor (TPS) is required for operation of the EFI system. An EFI system requires a throttle position sensor to indicate to the ECU when the throttle plates are closed or being opened/closed. A TPS is also used for the Alpha-N fuelling profile.

Where this is located will again, be a challenge.

The fuel system requirements is a significant installation.

The idle air control (IAC) valve is an EFI requirement. The ‘85/’86 GW CFI system has a passive idle air system. The Speeduino ECU can use the original CFI passive idle air control system. In the initial CFI design, it was realized that an idle air control (IAC) system is required at idle and deceleration, otherwise the engine is being starved of combustion air. Most IAC installs use an electric “stepper” motor controlled by the ECU.

This post regarding taking the EFI ignition only install to a complete EFI install is quite short. The main reason for this is that the EFI fuel install has two components. Sourcing parts for the install, and doing the installation. Sourcing the EFI components is time consuming and necessary. How to install these components and where to install these in the limited space available is quite different. I submit that the installation of the various EFI components will consume the most time.

The silver lining regarding a partial or complete EFI installation is that it upgrades/modernizes your GW so that you can continue riding it into the future. An EFI upgrade/modernization may be less expensive than purchasing a newer or new motorcycle, especially if you intend to continue riding a GW.

 

[Rednaxs60]

I have posted that the posts on this thread is not a how to do an EFI conversion, but to discuss the requirement(s) for an EFI ignition only and a continuation to a complete EFI installation with regards to the components required and considerations when choosing the EFI components.

An EFI conversion is a significant project with significant time and cost investment. The components required for an EFI conversion are competing for a limited amount of available space. Honda’s CFI system installation made the best use of the available space. I would submit that the CFI system could be used as a template for a GW EFI installation.

Once an EFI ignition only installation has been installed, there are not a lot of components required for complete EFI installation. This is why the previous post was short regarding the continuation to a complete EFI install. As I mentioned at the start of this post, this thread is about EFI considerations, components, not a how to install an EFI system.

The OEM CFI ECU replacement/upgrade project I have embarked on would appear on the surface to be a straight forward conversion utilizing the OEM components with a few minor changes. This may have been the initial premise, but there are a lot of options/features available such as sequential fuel and ignition, that with a few additional changes, can be accommodated.

The Honda OEM CFI system design for the day was a significant game changer. The use of port fuel injection, a better fuel injection system than an ITB installation. The use of two camshaft sensors to emulate semi-sequential fuel injection, an ECU on-board system diagnostic system, and such. The engine tuning program, the use of “maps” for VE (fuel) and spark (ignition) tables. All state of the art and well ahead of the curve back in ‘85/’86.

The installation of an EFI ignition only and a continuation to a complete EFI installation is, in my mind, the way ahead for these older GWs. OEM installed parts for the engine ignition system and carburetors will get scarcer as time goes by. Installing an EFI system, partial or complete will keep these motorcycles on the road, and out of the scrap heap.

It has been mentioned that an owner has to do a cost benefit analysis to determine if an upgrade to the engine operating system(s) is worthwhile or not. Agree wholeheartedly; however, is the GW community ready to have these older GWs go the way of the Dodo bird – this is the question that needs to be asked.

 

[Rednaxs60]

A stable and adequate electrical power generation is paramount for any EFI system. If you have been the recipient of a failing/faulty battery in an EFI car, truck, motorcycle or other vehicles, you will know that when this occurs, all sorts of wondrous things start to happen.

I’ve mentioned previously that a well maintained and current battery – no older than four years, is a key element to consider with an EFI system. A faulty or failing battery can tax the charging system and components such that power is robbed from the electrical system operation, or components fail.

A battery does three things; starts the engine, absorbs electrical system spikes, and supplements the electrical system when the charging system is not producing enough power. The charging system for these older GWs is an RPM dependent system. A good battery only requires a short charge to bring it back to a 100 percent state of charge, after which, it absorbs a small trickle charge and is along for the ride. All power produced after this is used by the electrical system for normal motorcycle operation.

An EFI system requires an electrical system that maintains a system voltage of approximately 14.2 VDC, the reference voltage of the RR, be it an external or internal RR.

This is required because the ECU engine programming uses the electrical system voltage for engine operation and adjusting the various components that react to a voltage change such as the fuel injectors.

It is recommended that the voltage being used by the ECU, fuel injectors, and ignition coils be from the same voltage source so that the electrical system voltage that is sensed by these three EFI is the same, and the components will react to the same voltage fluctuation.

In this regard, it is necessary to ensure your bike’s electrical charging system is operating well. There have been fewer electrical charging system issues with the older non-CFI GWs. Most times, new owners of a 1200 GW especially the CFI models always query the electrical charging system, why does it fail and what can be done to mitigate any failures.

To bring this into perspective, you generally read about failures/issues more often than not. I submit there are a lot of older GWs on the road that do not have electrical system charging issues, but if so, do not comment on their issues on the various forums.

Difficult to recommend a way forward with regards to this issue. How well the GW is maintained, has it been off the “grid” for a while – barn find, in a garage for quite a few years. Inactivity is not a vehicles friend.

The best advice that can be given is to do the OEM specification checks to ensure that the charging system components are within the OEM specification tolerances.

 

[Rednaxs60]

It was mentioned that the 1200 carbureted GW ignition control module (ICU) controls the fuel pump. I have done some research into this and the two are interconnected, but not from a control standpoint, unlike the OEM CFI system ECU that does control the fuel pump.

The ICU provides a ground for the fuel pump relay. If you were to disconnect the ICU from the fuel pump relay and connect the fuel pump relay to an electrical system ground, the fuel pump circuit would work the same. You would have to provide a power source to the ICU for it to operate, but the end result is that the ignition system and fuel pump would operate the same.

Let’s explore this.

The 1000 and 1100 GWS use a mechanical fuel pump. This was changed to an electric fuel pump for the 1200 carbureted GWs. The 1000/1100/1200 carbureted GWs will operate without an electric, or mechanically operated fuel pump providing there is enough fuel system “head” pressure, ie a full fuel tank.

There are two questions that should be considered:

Do you want to control the fuel pump such that it initially starts, primes the carbs for “x” number of seconds, then stops, but once the engine is started, the fuel pump is operating again?

Do you want to control the fuel pump such that it initially starts, primes the carbs for “x” number of seconds, but if the engine is started before the priming time is finished continues to operate, or simply just operate regardless if the engine is started.

The above questions would configure the fuel pump operation in an EFI ignition only installation to work the same as the fuel pump in an OEM CFI system, or as originally installed.

When the key is turned to the “ON” position, the OEM CFI system fuel pump operates for approximately 3-4 seconds, then stops. The fuel pump starts immediately when the engine starts. If the engine is started before the fuel pump priming time expires, the fuel pump continues to operate, does not stop. The priming time for the fuel pump can be adjusted in “seconds” in the engine tuning software.

This would be beneficial with these older carbureted GWs. I have not read about an owner having turned the ignition key of a 1200 GW carbureted engine to the “ON” position, and left it on for a good amount of time without staring the engine. I would think that prolonged operation of the electric fuel pump without starting the GL1200 engine would flood the carburetors, possibly forcing fuel into the various cylinders. This was an issue back in the late ‘60s early ‘70s when mechanical fuel pumps were being substituted for electric fuel pumps – just a thought.

Installing a Speeduino ECU will allow you to configure the ECU to control the fuel pump start/stop. You do not have to have the new ignition ECU perform this function, you could connect a ground wire to the fuel pump relay and operate the fuel pump.

Wiring the fuel pump so that the ignition ECU controls it will allow you to change from a low-pressure fuel pump to a high-pressure fuel pump should you decide to continue on with a complete EFI installation. One less issue to be concerned with.

The 1000/1100 GW mechanical fuel pumps use an engine camshaft to operate. Socrace on the NGW forum used this position to install the second engine rotation sensor (camshaft sensor) because he went to sequential ignition. He used a Hall Effect sensor instead of a VR sensor, works better at low engine RPMs.

Switching the 1000/1100 GW mechanical fuel pumps to an electric fuel pump allows you to use the mechanical fuel pump position to install a second engine rotation signal (camshaft speed) for engine phasing that improves the ECU performance – beneficial for an EFI ignition only installation or the “full monty”. This is more challenging with the 1200 carbureted GWs as there is no readily available camshaft placement to use.

 

[julimike54]

Not positive but I have noticed the pump doesn't run after initial 'on' and no start. I took it as there is a built in pressure switch to turn 'off' the pump till pressure dropped. I could be wrong, haven't measured or tested.

 

[Rednaxs60]

Mike - good question. The start/stop of the fuel pump on the '85/'86 1200 FI models is a timed issue determined by the ECU programming.

When the key is turned to the "ON" position, the fuel pump starts and primes the fuel system. Priming is for 3-4 seconds then the fuel pump stops. When the engine is started the fuel pump comes on automatically because the ECU completes the power circuit for the fuel pump. If the engine is started during the priming cycle, the fuel pump continues to operate without stopping after the priming time is completed.

When the engine is turned off, the fuel pump is stopped.

The new Speeduino ECU I have installed on my bike has this feature, user defined time.

Fuel system pressure is another issue for discussion. The OEM fuel pump has a non-return valve built in that is designed to maintain the fuel system pressure after the engine is shut off. The fuel pressure will eventually bleed off because the fuel pressure regulator (FPR) allows fuel to return to the fuel tank because of the fuel system pressure, or the non-return valve in the fuel pump does not work as when new.

The new adjustable FPR that I have installed does not assist in maintaining fuel system pressure like the OEM FPR does, but this is not an issue. The fuel system is primed whenever the ignition key is turned to the "ON" position. I am perusing the forums and internet to try and find an adjustable FPR that would assist in maintaining the fuel system pressure. Not a high priority.

Cheers

 

[Rednaxs60]

The carbureted 1200 GW fuel pumps (FP) are low pressure, and the operation of this fuel pump is reliant on the ICU for the grounding circuit for the fuel pump relay. The ICU provides a pulsing ground for the FP relay such that it operates intermittently. The grounding pulses increase in frequency as the engine RPM increases and the FP runs faster. There is a vehicle bank sensor that serves the same purpose as the FP shut off sensor of the ‘85/’86 1200 FI models.

The ignition cruise relay is grounded through the vehicle bank sensor energizing the ignition cruise relay providing power to the ICU and coils. When the bike is on its side the vehicle bank sensor grounds the power to the ignition cruise relay stopping the power flow to the ICU and coils, shutting the engine off. No power to the ICU, no power to the fuel pump.

The vehicle bank sensor will need to be used to control the power to the fuel pump in an EFI ignition only installation. The fuel pump relay 12 VDC supply would be tied into the ignition cruise relay power supply. When the bike is on its side, the vehicle bank sensor will ground the power wire to the ignition cruise and FP relay stopping the engine.

The new EFI ECU will be powered from the ignition cruise relay as per the original ignition system design, as will the coils.

The 1100 ignition and fuel systems is different from the 1200 ignition system as will be the 1000 ignition and fuel systems. There is no vehicle bank sensor indicated in the OEM service manual, fuel is stopped when the engine is not operating – mechanical fuel pump. There does not appear to be a sensor that would stop power going to the coils or spark units (coil drivers).

The 1100 has two ignition system designs depending on the year. The ‘80/’81 ignition system has a pulse generator for each pair of cylinders, but a single spark unit for all cylinders. The ‘82/’83 ignition system has a pulse generator and spark unit for each pair of cylinders.

The benefit to a 1000/1100 EFI ignition only installation is that with the change you have a camshaft sensor placement available for that second engine rotation input that provides engine phasing, this is in addition to using the mechanical fuel pump position.

Lots more to discuss.

 

[Rednaxs60]

Let’s take a. side trip and discuss the issue Safety, personal and equipment. Not going to spend a lot of time on this because a person’s perception of this issue varies from person to person.

Rambozo on the GW Docs forum is correct regarding fuel pump and engine ignition control. You do not want fuel spewing all over the place when the bike is not upright. Honda got it right with the 1200s with regards to the electric fuel pumps, high or low pressure, and the engine ignition system. The fuel system and engine ignition system is designed to stop the engine from operation when the bike is not upright. The carbureted 1200s fuel and engine ignition system design is different than the 1200 FI systems, but both achieve the same aim. The 1000/1100 GWs are different again.

Rambozo’s posts regarding the fuel pump safety issue had me reviewing the information available in the Electrical Troubleshooting and OEM Service manuals. To piece together a complete picture, it was necessary to review the information regarding the operation of the fuel and engine ignition systems in these manuals to get a clear, concise picture of the fuel and engine ignition systems as designed by Honda.

Safety issues are not always adhered to and there are many examples of this in the motorcycle world.

You get to cobble the EFI information you have found and put it together into a project plan, then review that plan against a known EFI installation if available, to make sure that you have not missed anything. Hopefully, safety issues have been considered and are at the top of your list or very close to it.

I have noticed with any specific industry that the DIY backyard mechanic researches an issue quite thoroughly and can find information that those in the trade may or may not know about. This is quite common because a trades person knows that what is being used works, is safe and provides the customer with a good product with the caveat that regardless of what is done, you can’t please everyone all the time.

This thread is to discuss partial or full EFI installation considerations regardless of the GW or any motorcycle in question, not to tell you how to do it. I’ve been researching and pursuing information regarding the EFI for over four years. The DIY backyard mechanic is at a disadvantage when it comes to a partial or full EFI installation.

Hopefully by the end of my dissertation, I will have discussed most of the EFI installation concerns and considerations that inquiring minds want to know. This includes having my thoughts on the subject challenged including how systems work and such.

I’m open to queries on specifics about the EFI system. If there are specific queries regarding the EFI system or components that would be a beneficial discussion item to this thread. please ask.

My ’85 1200 Limited Edition FI bike is my retirement project, and because of some of the CFI components being long in the tooth, I am doing a CFI ECU upgrade/replacement project that has blossomed into a modernization of the CFI system. Not an easy project, but not insurmountable. It is because of this project that I have decided to delve into the EFI world, and learn as much as possible about it. In retirement, have to have a reason to get up and go every morning.

Lots more to cover.

Cheers

 

[DaveO430]

The carbureted 1200 GW fuel pumps (FP) are low pressure, and the operation of this fuel pump is reliant on the ICU for the grounding circuit for the fuel pump relay. The ICU provides a pulsing ground for the FP relay such that it operates intermittently. The grounding pulses increase in frequency as the engine RPM increases and the FP runs faster.

That is incorrect. The fuel pump relay gets the same pulse as the ignition coil, the right one IIRC. This energizes the relay but it is constant power, not pulsed. The fuel pump itself does the pulsing according to how fast it needs to pump to keep the bowls full.

 

[Rednaxs60]

Good morning Dave. Thank you for commenting; however, the information I have provided is from the Electrical Troubleshooting manual. Photo of page:


I would have thought the same as you, but Honda describes the circuit differently.

Reviewed the ignition circuit schematic in the OEM service manual and understand the issue. The coil (for cylinders 3/4) and fuel pump relay are controlled by the ICU, same circuit. There is a 12 VDC power supply to this coil, but it is not connected to the fuel pump relay. The ICU controls the coil by providing a pulsing ground. This pulsing ground is used by the fuel pump relay.

The fuel pump relay has a separate 12 VDC power supply (splitting hairs so to speak - 12 VDC power comes from the same place, different circuit maybe) and the ICU provides a pulsing ground for this relay that is, as mentioned, shared with the coil for numbers 3/4 cylinder. I should have mentioned that the fuel pump runs faster and more constant as engine RPM increases.

Cheers

 

[dan filipi]

Does the fuel pump still use any kind of pressure switch or regulator?

 

[Rednaxs60]

Good morning Dan. The short answer is the fuel pump does not use a pressure switch, and pressure is regulated by a fuel pressure regulator, not the fuel pump.

The OEM fuel pump can provide fuel up to approximately 65 PSI. There is an internal recirculating valve that will recirculate the fuel if the fuel pressure exceeds this value. This information is from the CX500 turbo OEM service manual. No reason to think Honda changed fuel pumps for the 1200 GW FI models, but Honda might have.

The fuel system pressure for the 1200 GW FI models is regulated by the fuel pressure regulating (FPR) valve. Static fuel system pressure is approximately 36 PSI and dynamic (engine started) 28 to 32 PSI. The FPR is located at the end of the fuel rail after the fuel injectors and has a return line to the fuel tank.

I operate the fuel system of my '85 GW FI model at 40 PSI, have installed an adjustable FPR. Could have tried to emulate the OEM fuel system design pressure, but went with a fuel pressure that was closer to the fuel injector test pressure.

The fuel system pressure for the carbureted 1200 GW is not specified in the OEM service manual, only fuel pump flow rates. Reasonable to expect this to be a low pressure fuel pump that will not flood the carburetors when the engine is at idle, hence the intermittent operation of the fuel pump as controlled by the ECU. There is no fuel return line to the fuel tank, or FPR vv on the carbureted 1200 GW models.

Cheers

 

[Rednaxs60]

Time to put the fuel issue to the side and look at the EFI ignition only installation, and we’ll start with the carbureted 1200 GW models. A lot of the following information has already been discussed, but this section of the thread is about an installation as if you are going to do one.

Parts/components required for this installation have been identified and discussed. These are:

Engine Control Unit (ECU): ECU of choice
Crankshaft 75 mm missing tooth trigger wheel: 36-1
Throttle position sensor (TPS)
Coil driver(s)
Crankshaft sensor: VR or Hall Effect
Coolant temperature (CLT) sensor
Inlet air temperature (IAT) sensor

Dash Digital Tach Indication - Updating the 1200 ignition control system may result in the coil signal being used for the dash digital tach indication not working. It is recommended that you instrument the dash digital tach signal to determine what it is so that should you not have a digital tach readout, you can duplicate the original tach signal. I would surmise that keeping the wasted spark system should not affect the dash digital tach indication, but it may. This is an issue with my ECU upgrade/replacement project in that going to sequential ignition has changed the fuel injector signal to the Travel Computer and the dash digital tach does not work. This is an ongoing issue for my project that needs to be resolved.

The first order of business is to determine which aftermarket ECU you are going to use. I have mentioned that my focus will be on the Speeduino Project family of ECUs and respective clones.

This is important in that each ECU, while it generally has the same features, may be configured in different ways. Micro/Mega Squirt family of ECUs are calibrated differently than the Speeduino Project ECUs. There is a lot of commonality in the information between these two ECUs, but this is for information only. The workings of these two ECUs, how the information is input into the tuning software, and how the information is displayed depending on the feature can be different.

The budget for the ECU is a consideration. You may be able to find a used Micro/Mega Squirt for a reasonable price.

The Speeduino Project ECUs and clones are relatively inexpensive depending on your location. The Speeduino interface boards are available with all the components installed and soldered on the interface board, or if you are up for a challenge, you can order the interface board with the components not installed and solder the components yourself. I have viewed many videos regarding this and the person doing the video makes it look easy.

You may want purchase a complete ECU that comes with the ECU enclosure, and external harness connectors and/or wiring already done for you.

Where are you going to install this new ECU? There is limited space available and because of this, choosing the new ECU that has a similar footprint to the OEM ICU is a good decision.

Consideration should be given to future proofing this installation; however, you must separate the romantic notion of going to a complete EFI install from the reality of such. The minimum ECU specifications I would recommend are:

• 2 injector output channels
• 2 coil output channels
• Dedicated tachometer output
• 4 medium/high current outputs (idle, boost, VVT, fuel pump, fan, etc)
• IAT, CLT, TPS, and O2 inputs (protected)
• On-board MAP sensor
• Stepper idle control through board mounted DRV8825 accessory PCB
• VR conditioning through board mounted VR conditioner accessory PCB

A connection for a barometric sensor may be in order especially if you live in an area of mountainous terrain, travel from a higher to lower elevation or the other way round. Some of the more feature rich ECUs have the MAP sensor and barometric sensor already installed on the ECU interface board.

You will need to purchase the tuning and analytic software packages, in this case Tuner Studio and MegaLogViewer. Recommend purchasing the software licences.

Having gotten this far with the purchase of the ECU and tuning software making the project “feel” real, start reading, reviewing, watching videos. I expect this has already been happening. I submit that compiling all this information into a coherent way ahead may not necessarily happen at the start. It has been mentioned that tuners are into concepts, or specific operating issues. This is true and you need to sift through their information to make sense of it; however, the more you review the information at hand and start to connect the dots, information that you read or whatever, that did not make an impact will rise to the forefront such that you will be able to understand it and relate it to what it is intended for. It’s the “oops” I missed that scenario, or as it was mentioned to me, an “epiphany” moment.

Cheers

 

[Rednaxs60]

Taking this installation piece by piece. The next component to discuss is the crankshaft trigger wheel and sensor.

A recommended crankshaft trigger wheel is the 36-1 missing tooth trigger wheel. Any trigger wheel that the number of teeth divides evenly into 360 can be used.

The 1500 crankshaft trigger wheel is a 12-1 missing tooth trigger wheel and will fit on the 1200 crankshaft between the crankshaft timing belt pulleys. A small key can be made to secure this trigger wheel to the crankshaft.



The 12-1 and 36-1 trigger wheels are “sandwiched” between the crankshaft timing belt pulleys. The diameter of the 36-1 trigger wheel will be 75 mm.

You will most likely have to drill out the centre hole of the 36-1 trigger wheel to the correct crankshaft diameter. Recommend this be done by a machine shop so that the crankshaft hole is exactly centred. I tried doing this with the tools I had but managed to offset the hole creating more work than was necessary. The machine shop can also machine a small notch for a “key” to be used.

The annotated picture shows the trigger wheel installed and with descriptions of the various uses such as timing marks, where the timing case pointer mod is installed.

The orientation of the trigger wheel on installation is not important. There will be a procedure to determine the initial, approximate trigger angle for the ECU of choice. Once the initial trigger angle is determined, you will have to verify #1-cylinder TDC position with a timing light. Once the timing is set by doing this, further adjustment of the trigger angle should not be required. This is an example of the trigger angle calculation prior to checking the engine timing with a timing light as annotated by PSIG on the Speeduino forum:



Recommend that you read the manual for the ECU of choice for a detailed description of how to calculate the initial trigger angle.

The engine case timing mark pointer is installed using the upper sensor securing boss as illustrated in this picture:

This timing indicator modification is an easier way to check the engine timing, no oil to deal with and viewing space is not an issue.

The 36-1 trigger wheel teeth and valleys represent 5 degrees of ignition timing. What this means is that once you have timed the engine for #1-cylinder TDC, each tooth or valley between the teeth will indicate a timing change of 5 degrees. For example, you set your engine idle at 10 degrees BTDC, the timing indication will have moved 1 tooth and 1 valley, a distance of approximately 5mm.

The crankshaft sensor can be the OEM VR sensor. This sensor works well, but you will need to have an ECU VR conditioning board installed that converts the VR sensor sine wave output to a digital square wave signal. The other option, and the option I settled on is to install a Hall Effect sensor that outputs a digital square wave signal eliminating the need for a VR conditioning board. Socrace on the NGW forum, was the impetus for this as he found the camshaft OEM VR sensor did not provide the ECU with a reliable signal and this results in “sync” losses. Changing the crankshaft sensor, or camshaft sensor (if installed) can be construed as a best practice.

“Sync” losses are the result of the ECU not receiving a reliable, constant signal from either a camshaft or crankshaft signal or both. “Sync” losses can be the result of a component not operating as expected, and this component affects the crank or camshaft signal to the ECU. The reason for the “sync” losses must be discovered and eliminated before any engine tuning can progress.

A Hall Effect sensor is a 3-wire sensor; 5VDC power, ground and signal wire to the ECU. This sensor is grounded at the ECU and the 5VDC power signal is from the ECU.

This Hall Effect sensor can be installed in the same position as the lower PG sensor:



The Hall Effect sensor that I am using for crank and cam shaft signal is the Cherry GS10071.

 

[DaveO430]

Good morning Dave. Thank you for commenting; however, the information I have provided is from the Electrical Troubleshooting manual. Photo of page:

View attachment 50628
I would have thought the same as you, but Honda describes the circuit differently.

Reviewed the ignition circuit schematic in the OEM service manual and understand the issue. The coil (for cylinders 3/4) and fuel pump relay are controlled by the ICU, same circuit. There is a 12 VDC power supply to this coil, but it is not connected to the fuel pump relay. The ICU controls the coil by providing a pulsing ground. This pulsing ground is used by the fuel pump relay.

The fuel pump relay has a separate 12 VDC power supply (splitting hairs so to speak - 12 VDC power comes from the same place, different circuit maybe) and the ICU provides a pulsing ground for this relay that is, as mentioned, shared with the coil for numbers 3/4 cylinder. I should have mentioned that the fuel pump runs faster and more constant as engine RPM increases.

Cheers

But they are wrong. It wouldn't be the first or last time they make a mistake in a manual. Find one to check, I will guarantee the fuel pump gets constant power when the engine is running. The pump has a magnetic coil, a contact set and a spring.When the spring pushes the plunger all the way in it hits the contact and the magnet retracts the plunger. When the system gets pressure the plunger stops and doesn't retract again until the pressure goes down & it hits the contact again. It is only the spring that makes the pressure.
It wouldn't make sense for the pump to still be pumping at a high rate when decelerating, RPMs still high but using very little fuel.

 

[Rednaxs60]

Spark Units, aka Coil Drivers (CD) and coils are my next discussion items. Coil driver9s) are required because the OEM wasted spark coils are “dumb” coils, as are most, in that these coils do not have an integral coil driver.

Socrace on the NGW forum tried the 1200 GW FI model spark units and these work with an aftermarket ECU. His observation were that the 1100 coil drivers – spark units were not up to the task. Socrace decided to use the GM HE 7-pin coil driver in his install. I say used because he has sold his retrofitted GW FI bike. Socrace did trial the 1200 GW FI model spark units and these worked. This was my experience as well.

Here are a few examples of coil drivers that are used for an EFI install starting with the Bosch 211 4-channel CD, next the PRW-2 CD, then the GM HEI 4-pin CD. The shape of the GM HEI CD is because it is designed to fit inside a distributor – the 7-pin CD is approximately the same size:



I have the GM HEI 4-pin CD, but opted for the Bosch 211 CD instead of using the OEM CFI spark units mainly because using other coil drivers may require the use of two or even four CD units. Space is limited on a motorcycle, hence the use of the Bosch 211 CD especially if you are going to progress the EFI install and use sequential ignition.

You can also change the OEM coils for new aftermarket coils. If you decide to do this, recommend purchasing coils that have the coil data such as dwell times. This information is entered into the tuning software, and you should not have to experiment with the coil dwell settings to optimize the install.

There are aftermarket coils on the market that have the coil driver integral to the coil(s) called “smart” coils. This eliminates the need for a separate coil driver. An example of this is the VAG coil pack for 4 cylinder wasted spark application:



The silver component is the integral coil driver.

If you are keeping the OEM coils, these work quite well, there will not be a fitment issue. These aftermarket coil packs for a wasted spark installation can be quite large and be difficult to install in the same space as the OEM coils. I installed an aftermarket coil pack in the same space as the OEM coils, a tight fit but it worked. A deciding factor that determined the style of aftermarket coil pack was that the spark plug wires had to be oriented similar to the OEM coil spark plug wire configuration.

This picture shows my test set up with the aftermarket coli pack and the Bosch 211 coil driver. Worked well:



This is a picture of the aftermarket coil pack installation where the OEM coils are installed:



I have removed this coil pack setup. The CFI system I have on my bike has sequential ignition using coil-on-plug units and I have kept the Bosch 211 4-channel coil driver.

What to use and where to install the component(s) is only limited to your imagination and resourcefulness.

These aftermarket coil packs such as the one I trialed are “dumb” coil packs that require a coil driver, but may be used in an OEM GW ignition system. If a person was so inclined to use/experiment with new coils, this coil pack can be installed and connected to the ignition system using the existing OEM wiring. The issue would be the coil dwell time. Using this or other coil packs is no different than using the different aftermarket coils, or coils from a GL1500 on the 1000/1100 /1200 GWs that can be read about on the various GW forums.

There is guidance regarding the installation of coils in an EFI system if coil dwell time data is not available, and one of these is called the finger test. Once you get the coils installed, the engine operating and are starting to dial in the EFI components, you need to calibrate the engine tuning software for coil dwell time. This is done by increasing the coil dwell time until the engine starts to falter, then backing off the coil dwell time to the optimal timing. You will, at the same time, use your fingers to discern the coil temperature. The coil should not be so warm/hot that you cannot touch the coil(s), should be warm to the touch so that you can keep your fingers firmly pressed against the coil(s).

This coil pack requires a single multi-channel coil driver or two single coil drivers to operate. Word of caution, never connect a “dumb” coil that requires a coil driver directly to the ECU.:



This coil pack is used in a variety of cars, and is inexpensive at approximately $25.00 CDN.

Wiring of the coil driver(s) and coil packs in conjunction with the other EFI components will require planning to minimize wire duplication and ensure connecting to the new ECU is correct.

 

[Rednaxs60]

Next discussion item is the manifold absolute pressure (MAP) sensor. Do you really need this, yes. It is the backbone of an EFI system, it provides the engine load indication that is need for engine tuning, specifically the VE (fuel), spark (ignition timing) and AFR tables. You can use the throttle position sensor (TPS) for the engine load, but using the TPS for the engine load calculation is far more challenging and for most installation, not required.

Most aftermarket ECUs that will be considered for an EFI ignition will have an on-board MAP sensor. This sensor, generally the MPX4250 rated for a maximum of 2.5 bar, is reliable and minimizes installation issue:



If there is an on-board MAP sensor and you decide to not use it for whatever reason, you will have to modify how the on-board MAP is connected to the interface board so that you can bypass the on-board MAP installation.

Let’s keep the on-board MAP sensor and discuss the engine vacuum, and how you may connect it to the MAP sensor.

Each carburetor has a vacuum connection to balance the carburetors. It is recommended to use all four carburetor vacuum ports and then connect these to the MAP sensor.

The challenge is to decide how you want to connect to the MAP sensor and where to install it. Socrace on the NGW forum took the four vacuum connections and routed these into a vacuum block to “blend” the cylinder vacuums, then a single hose from the vacuum block to the MAP sensor. This is an example of a vacuum block that I have installed on my ’85 1200 FI model, works well:

 

[Dusterdude]

Or you can tap into the intake plenum and draw vacuum from there.interesting stuff red.keep it up.

 

[Rednaxs60]

Or you can tap into the intake plenum and draw vacuum from there.interesting stuff red.keep it up.

Tapping into the air plenum would not be my preference primarily because the plenum is too far from the engine cylinders to provide a good MAP signal. The MAP vacuum takeoff(s) on the '85/'86 1200 FI models are quite close to the engine heads as shown by this picture. I would think this is an example of where you should try to locate the MAP vacuum takeoffs:



I submit that tapping into the plenum because of its size and where it is located, you would be operating the engine with a MAP value close to atmospheric all the time. This would defeat the purpose of having a MAP sensor and engine operation would be terrible. The engine might operate, but not as efficiently as one would think; ergo, have the MAP vacuum takeoff(s) as close to the cylinder heads as possible.

This might be a different scenario if you were to use a mass air flow (MAF) sensor in the plenum, but this is another level of complexity that you do not want at this stage. Mass air flow versus manifold absolute pressure is two different kettles of fish so to speak, not to say it cannot be done.

Cheers

 

[DaveO430]

Or you can tap into the intake plenum and draw vacuum from there.interesting stuff red.keep it up.

The MAP has to be connected to the engine side of the throttle plate to get manifold vacuum. The plenum is on the wrong side of it and has no vacuum.