1985 Limited Edition and 1986 SE-i Fuel Injection Motorcycles

[Rednaxs60]

Starting a new thread to hopefully consolidate a lot of information on the Computerized Fuel Injection (CFI) system on these motorcycles, and to demystify the CFI system. Once you are past the CFI system, these motorcycles are similar to its carb model cousins.

Not a lot of information about these except in the OEM Supplement manual that is probably all you will need. The inference here is that if you are going to own one of these FI model Gold Wings, you need the OEM Supplement manual. Without it you will ask a lot of questions and get a lot of opinion.

The information in the Supplement is good but there are idiosyncrasies that are not mentioned in this manual.

There are components and calibration procedures that are not specifically detailed. Will list alternate components in this thread.

There are many posts on why these FI models should be avoided or not such as parts availability, knowledge base, and such. I read a lot of threads/posts regarding the carb models and there is a lot of opinion about these as well.

I have a vested interest in this as I intend to keep my '85 Limited Edition for the long term, my long term retirement project. Having made a couple of "oops" in the past that I have had to correct has made me browse the internet for information.

I will put my thoughts together and post them here. Consolidate what I have posted elsewhere.

Hopefully the information in this thread will assist others that own one of these FI motorcycles.

 

[pidjones]

This will be good. The LTD and SEi were excellent bikes. I wonder if they were a marketing experiment by Honda, as technically they had few short-comings, all of which their engineers could overcome. Then, no FI for 17 years! I only traded mine to get more room (and power) for 2-up riding on the GL1800.

 

[Rednaxs60]

Honda probably knew that fuel injection was coming no matter the cost. Fortunately for Honda and other OEMs, environmental legislation did not catch up to the motorcycle industry for quite a few years. This allowed the OEMs to continue with the use of carbs. The GL1500 Gold Wing was a bit of a hybrid for Honda in that it emulated an FI system very well. Read about this engine when I had my 1500. If you did not know the difference you would think you were getting a fuel injected motorcycle.

Lot of information to compile.

 

[Rednaxs60]

History of Honda’s Computerized Fuel Injection (CFI) system goes back to the early 1980s. Started with the 1982 CX500 Turbo, and followed in 1983 with the CX650 Turbo. This was a revolutionary system, totally different from the competition. My intent with this thread is to discuss the CFI system as installed on the ’85/’86 GL1200 Gold Wing.

There are a lot of books on fuel injection on the market that give good, detailed information. Some are recommended over others, but the information will be the same. Recommend one if not more of these books grace your motorcycle library.

I have seen and read forums posts regarding these fuel injected motorcycles. Some posts are very complimentary, some not so much. The downside to these older FI motorcycles is that expertise in diagnosing/troubleshooting and repairing is not readily available. This is not just for the FI models, but carbs models as well. Owners of the GL1500 Gold Wings, and early model GL1800s are experiencing the same issue. The bottom line, if you are not a DIY back yard mechanic, or do not have access to a friendly mechanic that is familiar with these older fuel injected bikes, maybe the best bet is to move on up to a more recent, late model motorcycle.

These early fuel injected Gold Wings are very reliable, but when an issue comes to the fore, troubleshooting the issue can be time consuming. Time, time is your friend. Nothing in the early FI world is quick. Proper diagnosing of the issue is the key. Having a troubleshooting sheet that you will use to eliminate components is a good second step. The first step is to acquire the OEM service manuals for these motorcycles.

If you read a forum thread or post that mentions that a car FI system is different from a motorcycle FI system, this is not the case. Every FI system installed uses the same components, it’s how these components are used and where these are located that is different. Throttle position sensors can be single or dual output. An FI system may use a manifold absolute pressure sensor, or a manifold air flow sensor. All modern FI systems, motorcycle included have exhaust gas sensors. The ECUs will be very different, but all are probably map-based controllers. Do not be dissuaded by these comments.

Motorcycles engines can be converted from a carb model to a fuel injected model. This is not for the faint of heart. You must be willing to go back to school so to speak, learn a new language, that of fuel injection. Research the internet and motorcycle forums for information on FI components, the ECU - very important, and read about the trials and tribulations that people have had to get conversion to fruition. Many have started down this road, but a lot do not complete the project.

A conversion from the carb to the FI world should be seen as a personal project, something that if completed, can be regarded as a significant accomplishment. A conversion can be beneficial as a daily rider, or future touring motorcycle. The bottom line here is that this is a project, not a refurbishment to a close to original configuration. The amount of time to bring this type of project to fruition depends on how much time you have to spend, what is your budget, do you have the tools and equipment that will allow you to minimize third party costs such as welding, machining and the likes.

Purchasing a motorcycle converted from carbs to fuel injection should be considered a project as well.

Lastly, do you enjoy doing projects such as this? This is most important, something like myself doing this thread. I enjoy working on my ’85 FI Gold Wing. I enjoy thinking about an issue and trying to consolidate information into a clear, concise narrative that may not be entirely complete but a stepping stone to further understanding.

These early model FI Gold Wings are complimented on favourably. Most owners have moved on to more modern motorcycles, but still have fond memories of owning one of these early model FI Gold Wings. I have had people approach me in a parking lot to discuss my ’85 Gold Wing, specifically because they owned this particular model.

 

[Rednaxs60]

When you research the internet, you will notice that it is reported that after the 1983 CX650 Turbo FI the next FI motorcycle is the 1998 VFR800 FI model. Fortunately, this is known to be incorrect as there are the 1985 Gold Wing GL1200 Limited Edition and the 1986 Gold Wing GL1200 Special Edition- injected (SE-I).

The CFI system installed on the CX500 turbo was the first use of Honda’s proprietary Programmable Fuel Injection (PGMFI/PGM-FI) system.

Honda started research and development of this PGM-FI system 6 years before it was installed and used in the 1982 CX500 turbo motorcycle.

Honda deviated from the industry norm of the time and produced a map-based controller. This Electronic Control Unit (ECU) relies on inputs from the various sensors in the

The ECU relies on inputs from the various CFI system components to determine the ECU output from the internal pre-defined lookup table.

A map-based controller is one that uses a map, a pre-defined lookup table, that uses the sensor inputs to determine the controller output. The benefit of a map-based controller is that smaller sections of the map can be modified, or the entire map set of values can be changed out. This map is similar to a mathematical matrix with an “X” and “Y” axis.

In the early/mid ‘80s this was a significant engineering achievement. This style of ECU with no external connections has done a superb job of ensuring successful operation of these early FI motorcycles.

The downside to this is that very little if anything is known abut the pre-defined tables in these early ECUs, and there is no external connection to do any troubleshooting/modification of these pre-defined lookup table(s). I would surmise that an enterprising individual could determine the configuration and content of the maps used in these ECUs.

The mapping of these early model Gold Wing CFI systems are in the same category as the throttle plate lever stop screw used for calibrating the throttle position sensor (TPS). The why it is set where it is is not known, and the don’t touch this stop screw when calibrating the TPS applies to the ECU as well.

These early Honda motorcycle CFI system ECUs were the first to have a built in diagnostic program that checked the CFI system for any faults. Honda used this to determine if the engine was ready to start. These ECUs would display an error code on the left side of the ECU, and illuminate the electronic dash FUEL SYSTEM indicator light to let the rider know there is an issue.

The ECU is the only wildcard that I have found with the CFI system. It is a very robust component that has stood the test of time. Unfortunately, as with all man made components, nothing is forever. I would recommend having a spare ECU, or embark on an aftermarket upgrade using a Micro Squirt or Speeduino unit, or equivalent unit.

 

[Rednaxs60]

The Engine Control Unit (ECU) generally turn CFI components on/off by controlling the ground of the Computerized Fuel Injection (CFI) component. 12 VDC signals to CFI components are provided by the motorcycle electrical system. The CFI components that require a 5 VDC input get this from the ECU.

The ECU is integrated into the motorcycle infrastructure and is connected to the travel computer, and the electronic dash.

The CFI system has a variety of sensors that provide inputs for successful engine operation. The CFI system components that are monitored by the ECU are:

Crankshaft position sensor - Ns
Camshaft position sensor - Gr/GL
Manifold Air Pressure sensor - PBR/PBL
Inlet air Temperature sensor - T1
Engine Water temperature - Tw
Throttle Position Sensor - TPS
Numbers 2 and 4 engine cylinder injectors
Numbers 1 and 3 engine cylinder injectors
Engine Control Unit (ECU) sensor - P1

Other components that are not monitored by the ECU - may be controlled by the ECU, but are critical to the operation of the engine are the spark igniter units, fuel pump, idle air control (IAC) valve.

The fuel pump shut-off relay controls power to the entire CFI system should the motorcycle have a mishap and the motorcycle is no longer on two wheels.

The fuel pump relay #5 is controlled by the ECU in that the ECU provides a ground for this really power source. The logic in the ECU grounds relay #5 for approximately 2-3 seconds. In this time the fuel system is pressurized to approximately 35 PSI static. This is enough to “prime” the fuel system to enable an engine start. When the engine starts, the fuel pump comes back on line because the ECU provides a ground for the fuel pump relay #5.

Power from relay #5 also powers the Idle Air Control (IAC) valve.

The ECU system uses a Speed Density and Alpha-N mode to control the engine operation.

Speed density mode uses the PB, TPS, air inlet and water temperature, crank and cam shaft sensors, and engine RPM to determine the correct engine timing and fuelling requirements at idle and low engine RPM, generally under 3000 RPM. The Alpha-N mode uses the same sensors as the speed density mode with the exception of the PB sensors. The PB sensors contribute to the ECU decision making up to approximately 3000 RPM after which the PB sensor(s) output to the ECU is maxed out, and so is the usefulness.

The ECU does a CFI system check when the key is turned to the ON position. The ECU logic is looking for open circuits, and sensors being out of calibration and resistance. This system check takes approximately 2-3 seconds and if the CFI system has no faults, the engine is ready to start.

You can follow the ECU system check by focusing on the electronic dash. The indicator lights on the right side of the dash will illuminate. These indicators are for oil pressure, FUEL SYSTEM - Honda’s early CFI system CFI/check engine light, and cruise control indicators.

The FUEL SYSTEM indicator light will go out, followed by the cruise control lights. The oil pressure light stays illuminated until the engine starts and there is oil pressure.

The FUEL SYSTEM indicator light is the check CFI system light, and has nothing to do with the fuel system as such. The fuel pump and fuel system pressure is not monitored. The other FUEL indicator light is a warning light that there is a low fuel level in the fuel tank.

The Electronic Travel Computer (ETC) uses the ECU ground wire signal for numbers 1 and 3 fuel injectors for the ETC fuel monitoring system.

 

[Rednaxs60]

Time to discuss the various components, systems that form part of the Computerized Fuel Injection (CFI) apart from the Electronic Control Unit (ECU).

Starting with the fuel system. Fairly basic, fuel pump, fuel filter, fuel rails, and injectors. Injectors will be done in a separate post.

Maintenance of the fuel system is a must with these FI models. A clean, filtered and adequate pressurized fuel source is a must because of the fuel injectors.

Fuel injectors are cleaned, and flow tested at an industry standard of approximately 40 PSI.

The fuel pump is rugged, long lasting, and no longer available. If it fails, two possibilities. Find a replacement pump, lots of information on the various forums regarding what pump to source, or a visit to an auto wrecker to find a used fuel pump from an early model Honda Civic/Prelude. Honda has been good to us in that a lot of the automotive parts/components from early model Hondas are a direct replacement for the motorcycle parts/components.

The fuel pump has an internal pressure relief/bypass system. At approximately 60 to 65 PSI the internal workings of the fuel pump will recirculate the fuel internally so as not to damage the pump or over pressurize the fuel system.

When an issue happens and it is thought to be the fuel system, a fuel system pressure test must be performed. The static fuel pressure, key ON - engine stopped, is 2.4 to 2.7 Kg/cm (34 to 38 PSI). The dynamic pressure, engine started and at idle is 2.0 to 2.4 Kg/cm (28 to 34 PSI).

The next test is to do a fuel pump flow test as detailed in the OEM Supplement. The fuel pump is required to flow a minimum of 630 cc (21.3 oz) per minute.

Having ruled out the fuel pump, or not, proceed to the next possibility.

The fuel filter should be changed if it is an OEM original. Fuel filters will cause flow and pressure issues as these become clogged with crud, dirt, etc. The fuel of today is relatively clean, but if it were that clean, wouldn't need a filter.

The OEM filters are not available, but there are suitable alternatives. I use a Beck Arney 043-089. Have to modify the mounting bracket to suit. Other alternatives are Hastings GF159 and Fram G3969.

The fuel injectors are very robust, well designed, low impedance units that have stood the test of time. Having these cleaned, refurbished, and flow tested is a good maintenance issue.

The fuel system on these FI models is overbuilt by today's standards. Every FI model motorcycle or automobile uses a high pressure fuel system. Most FI fuel systems use more modest components.

For example, the FI system on my 2014 CanAm Spyder 1330 cc engine uses fuel hose that is approximately 1/4" inside diameter. Slides onto the fuel filter and secured with oetiker clamps. The fuel filter is approximately 1 1/4" to 1 1/2 inch in diameter and 3" long. Achieves the same aim, much less expensive, and uses less space in a vehicle where space is generally at a premium.

Browsing the internet will provide a host of alternate possibilities.

The fuel pressure regulating valve is a long in the tooth component of the fuel system. This is a vacuum operated valve that is calibrated to regulate the fuel system at the OEM designed pressure. It returns excess fuel in the fuel system to the fuel tank - the fuel pump output is greater than the demand.

The internal component(s) get weak over time, specifically the internal spring. When this happens, the regulator will allow fuel to flow back to the fuel tank when the engine is shut down. This is not an issue when the engine is operating, could be but generally not because of the quantity of fuel the fuel pump discharges.

As with most parts for these FI models, an exact OEM replacement is not available. A browse of the internet will provide information on what can be a suitable alternative. It is necessary to find a unit that has a similar pressure specification, can be attached in the same manner, and allows for the CFI cover to be installed.

The fuel system pressure maintained by the fuel pressure regulator should be 2.0 to 2.4 Kg/cm (28 to 34 PSI). Injectors are cleaned and flow tested at approximately 40 PSI. Knowing this I would surmise that a fuel pressure regulator that has a pressure rating of 40 PSI would work quite well in these FI models, and be beneficial to the operation of the Gold Wing injectors.

To determine if the fuel system pressure has bled off when the engine is shut down, you can install a fuel pressure gauge and monitor the fuel system over a period of time, or let sit overnight and remove the fuel pressure test point. If the fuel pressure has dissipated, you know there is an issue.

To determine what the issue is, you need to rule out the injectors, fuel pressure bypass regulator, and fuel pump.

To rule out the injectors, remove the spark plugs and if you have one, use a small borescope to view the cylinders. If an injector is faulty and allowing fuel to pass through, there should be fuel in the cylinder.

To rule out the fuel pump, pressurize the fuel system, shut the fuel tank supply valve OFF, and disconnect the inlet hose to the fuel pump. There should be no fuel flowing from the fuel pump inlet. May be a bit of residual fuel from being connected, but this should stop.

To test the fuel pressure regulator, pressurize the fuel system, disconnect the fuel return hose. If fuel is leaking past, replace with a new unit. Take note of the fuel level in the fuel tank. Don't want fuel pouring all over the engine and work space.

Having mentioned these test procedures, if the fuel system is operating well, and the engine is performing as expected, wait until the next maintenance period to correct any issue.

If you have loosened the fuel system pressure test bolt to determine if there is fuel pressure in the fuel system, make sure you tighten this bolt before pressurizing the system to check the fuel pump and fuel pressure regulator.

A small maintenance item to be mentioned regarding this system is to use new sealing/crush washers when reconnecting any component. Make sure the sealing/crush washers have no burrs, and the mating surfaces are clean and free of any burrs, etc. A small imperfection on the mating surfaces is enough to have a fuel leak, very annoying.

 

[Rednaxs60]

If I haven't mentioned it, you need to have the OEM Supplement for these FI models. The '85 and '86 FI models are the same and utilize the same information. This manual is critical to troubleshooting these FI models. Without access to this manual, you will probably ask a lot of questions, and get lots of answers/opinions. Troubleshooting an FI model is different from troubleshooting a carb model. Components are not in the same place, and if it seems that a component is, this component may perform a different function.

 

[Rednaxs60]

This is a bit out of sync. The fuel system components are the fuel tank, fuel shut off valve, fuel pump, fuel filter, fuel rails, fuel injectors, fuel pressure relief valve.

The fuel pump has been discussed in post #7.

The fuel tank is relatively straight forward, hold approximately 21 litres of fuel. Has a small screen in the bottom of the tank. A hose connects it to the fuel shut off valve. This valve is in the system to use when maintenance is being done on the fuel system. Unlike the carb models that require the fuel shut off valve to be closed when the engine is not operating.

The fuel shut off valve is connected to the inlet of the fuel pump. A small cone filter screen is in the inlet to the fuel pump.

The fuel pump discharge is connected to the hose to the filter. It is a robust pressure hose that is overbuilt by modern standards and FI installations. The fuel pump discharge hose is attached to the fuel pump and secured with a spring loaded cap. This cap is a non-return cap.

An edit regarding the fuel pressure relief (FPR) valve. This valve can be tested by clamping the FPR valve return hose to the fuel tank. If the fuel pressure is maintained then all is well with the FPR valve. You can also disconnect the vacuum hose to the FPR valve. If no fuel comes out this connection, the internal diaphragm has not failed. I have read on several forums that if the fuel system has been contaminated with rust, crud, etc, it is possible that some of this has gotten through the system and could lodge in the FPR valve between the diaphragm and the FPR valve discharge pipe. This would keep the diaphragm off the seat when the engine is shut off allowing fuel pressure to bleed from the system.

The issue with the FPR valve is availability. The FPR valve is no longer manufactured so a lot of research is needed to find a suitable alternative that will fit where the original is located.