Upgrade to an '85 LTD Electronic System

Was discussing the fuel injector replacement with my son-in-law. We discussed his Moto Guzzi 1400 California and how it has 3 operating modes and can be modded with an aftermarket chip and tuner. I mentioned there is nothing like that on the Limited or SEi. Was looking on another forum regarding the C5 tuning kit and was wondering if there was anything out there in the aftermarket to upgrade the tuning on the '85 LTD or '86 SEi, possibly a chip change, or a means to change operating mode(s) on the fly. Interesting research project coming on.

Thinking about this, maybe a starting point is what can be done to an'85 Honda Prelude fuel injected car.

More to follow.

Interesting idea. Although you may find the only way to "adjustable" is an expensive megasquirt system. I haven't read of anyone actually getting it to work properly on any model bike though. So you may want to get the stock set up as thoroughly understood as you can first.

yes it seems FI project havnt gone well on oldwings .....id say theres no chip to buy for stock FI....but im really clueless here as i have no time in this at all ...its been out of my reach money wise for me to go after it...after seeing mostly failure on custom FI projects ..i have to say the stock set up must be pretty dam good when its working right ...flat 4s are totally balanced motor and i think getting the fuel system right is everything ...carbed or FI...off just a little brings in all kinds of running problems .....but if system is dialed in good the motors can really come alive ....to me stock carb bikes cv carbs beinng vacuum operated throttles work behind the motors needs and are late causing low rpm trouble spit and sputter and such if not really perfect in set up ...FI system actually work behind the game to as all sensors are basically monitoring things that already happened...but it seems the stock FI when right does much better job than the stock carbed bike ....be great for someone to actually get a FI oldwing really running pumped up ...im pulling for you...

Seems like modern bikes with multiple rider modes have a lot more inputs than your SE would have; such as traction sensors, ride by wire throttle, wheelie sensors. But you probably could have modes related only to engine power output. I think, just the C5, could give you that.

I would think that a ride by wire throttle would open up a whole bunch of possibilities.

This is an interesting idea. Don't intend for it to become an on bike project unless I were to find that the reliability was extremely good. I also don't want to take my daily ride and hamstring it by always playing with a new system. Maybe the second '85 can become a test platform.

Always best to keep one bike as reliable as possible.

Here is something I've been thinking about: for inputs you have wrist grip (WG) position and engine RPM. Output is carb throttle opening.

It would be programmed so WG position sets the desired RPM (not the throttle opening). So no turn of WG calls for 900 RPM, half a turn calls for 8000 RPM and with even increments in between.

So, for example, if actual RPMs are 2000 and WG is turned to the 4000 RPM position, the carb throttle would open enough to get to 4000 and then open and close to keep it there. If you start heading up a hill the throttle would open more to keep it at 4000 RPM with no change of WG needed. Would sort of be like cruise control.

The amount of increase in throttle opening would depend on how big a difference there is between actual RPM and desired RPM.

Just trying to imagine what it would actually be like in the real world.

Emulating the wire controls now over mechanical.

hmmm a lot to this stuff gees ... opcorn:

Good info all round. It is an interesting topic that I am starting to enjoy. Doing the research on the internet brings a lot of information to the fore real quick. This topic may never see a change to my bike(s); however, it may turn into a primer for FI systems. Lot of thoughts on what to do, control units, single port FI, multiport FI. I can see this being an interesting topic for those doing a SCC on a GW. There is a thread on the NGW site and the fellow is installing a supercharger on a GW.

I also take notes from what is posted here and do research on these as well. This is like going back to school and learning a new language, especially the acronyms. Find myself looking for definitions.

Thought I'd start with looking into the operation of the FI system. Most of the information I have found is from car forums and the automotive industry. The small car industry is rife with information because people want to get more out of these cars then was intended. I also think movies like "Fast and Furious" inspire the younger set to look into mods to make their cars similar to what they see.

I found one site that talks about the Mini as the platform to be modded. I like this one because in my youth, I helped a friend do mods to one of the original Minis, we were both 6'2" and it was an accomplishment to get the two of us in the front of the Mini. It's also a car that begs to be modded.

I will be using this as a starting guide for my research, comparing the automotive system to the '85 LTD FI system. Then moving on from there. Hope you have a good read. Cheers

The web site is https://www.minimania.com/A_Basic_Guide_ ... _for_Minis

Here is the info from that site as a start. Good primer on FI system.

Advantages:

If done properly, converting your Mini to EFI can have many benefits. The EFI Engine Control Unit (ECU) can control all aspects of the combustion of the air/fuel ratio under all conditions. For each and every load point throughout the rev range that the engine may experience, the EFI ECU can calculate the optimum timing and delivery of fuel as well as precisely when ignition will take place by supplying spark at exactly the right time in order to maximise power and torque. This results in an infinitely more flexible engine with wider power and torque bands.

With EFI, the engine will probably be more reliable, will run smoothly, be more economical (as fuel is not wasted) and have a longer lifespan. As the engine will be more fuel efficient, the combustion of the intake charge is better controlled resulting in fewer emissions, little or no carbon build-up within the engine and of course be much better to drive.

EFI ECUs can actually help prevent engine damage by not allowing full power and torque to be generated until all fluids are up to their normal operating temperature (an anti-thrash mode of sorts!). Nasty pre-ignition/pinging/detonation can be a thing of the past thanks to knock sensors, at the slightest hint of detonation the ECU can slightly alter the ignition timing to fend off potential damage.

Instead of having heaps of gauges on the dashboard, just look at the EFI ECU handset and they'll usually display everything from engine revs to oil pressure to the injectors' duty cycle (the amount of time the injectors are supplying petrol). Some brands of EFI ECUs have dashboard displays and data loggers (like some of the MoTeC ECUs used in Touring Cars) which would probably look fantastic mounted above your Mini's steering column. EFI componentry can also look damn good on a show car. A polished fuel rail, shiny braided fuel lines and gleaming intake trumpets can have crowds swooning.

If you are a serious racer and want to cut down your lap times, consider EFI closely, as some of the high-end EFI ECUs are excellent at data logging. Imagine being able to retrace every lap you've just done back in the pits on computer like the Touring Car guys do looking for ways to improve your car OR your driving. You can compare a multitude of different types of data such as speed through each corner for each lap, top speed at the end of a straight or even maximum engine revs. Make sure that the class your Mini races in allows full engine management, some don't.

All after-market programmable EFI ECUs I have seen possess a special cold-start function (no more playing with chokes), can automatically control auxiliary thermo-fans, can easily accommodate forced induction (such as a supercharger or turbocharger) and many more functions I don't have room to list here. Some EFI ECUs also possess an anti-theft function (which can be turned off if desired), such as a PIN-number that must be entered before the engine will start.

Disadvantages:

The disadvantages of converting your Mini to EFI are many. Ask yourself the following question: do you need EFI or are you and your engine perfectly happy with carburettor(s)? You must think carefully about what use your Mini gets. EFI conversions are only worthwhile if they are used on vehicles where the ultimate in performance and drivability are desired. If your Mini's main role is not really performance-based, I definitely don't see the need to convert to EFI.

If maximising power, torque and drivability are necessary, EFI MAY be the answer for you. If your Mini is used for venturing out onto our terrible roads as well as used for any racing events such as circuit sprints, hillclimbing, motorkhanas or tarmac rallies etc., then EFI's versatility MAY be of benefit to you.

There is no point converting to EFI if you cut corners. If cheap or inferior components are used (such as a fuel-only computer rather than a full fuel and ignition computer) then eventually you will probably wish you'd never started as the results are always far from satisfactory. You must also be prepared to outlay a lot of money. EFI conversions are not cheap, in fact they are usually hideously expensive. Steer clear of modern car's EFI systems, they aren't readily programmable and are difficult to get working correctly. Definitely stay away from mechanical fuel injection, a Weber or twin SUs will outperform an old mechanical fuel injection system easily (and be much cheaper).

You must be prepared to install all the parts required for EFI. A return line must be plumbed in (probably along with a new supply line), extra wiring for sensors and power supplies must be installed along with a myriad of bits and pieces to complete the installation. Only unleaded fuel can be used because the oxygen sensor that the EFI ECU usually relies on for input are easily poisoned by the lead in Super petrol (I'll briefly explain how EFI works later). To get a fuel with a high enough octane rating, use Premium Unleaded with a bottle of octane booster if running a high compression ratio (near or above 10:1).

Another factor to be considered is the time it takes to perform an effective conversion. Programmable ECUs use 3-dimensional maps to calculate when to fire the injectors and when to supply spark. Once the EFI installation is nearing completion, all the maps must be calculated, setup and installed by running the car on a chassis dynamometer (which is cheaper and easier than an engine dynamometer) under all load conditions throughout the rev range. Without these maps setup correctly it is a waste of time and money.

Electronic Fuel Injection conversions are not incredibly DIY-friendly, once installed and set up, its best not to fiddle too much. Possible points to consider are that EFI-equipped cars run very high fuel pressure (up to 45+ psi easily, so don't muck around with it) and it's also easy to destroy an EFI ECU and all of it's settings by playing around with the wiring, so be careful.

Finally, converting your Mini to EFI is a pretty big step. Due to the reasonably large expenses involved as well as the time required for an effective EFI installation, you might well consider this to be a good excuse for either starting a completely new project or to renovate your Mini. Although expensive, the most effective EFI conversions always start out with a completely fresh mechanical package in a good, sound bodyshell. Everything from the engine, gearbox and driveline package to the braking, cooling, electrical, steering and suspension systems must be in top condition. Remember that it is always the weakest link in the chain that breaks first.

How Electronic Fuel Injection (EFI) works:

Under full throttle, the EFI ECU will try to maintain the optimum air/fuel ratio the engine receives for maximum performance (a reasonably rich air/fuel ratio near 12:1) by interpreting the data it receives from all of the input sensors in what is known as 'closed loop' mode. The oxygen sensor mounted in the exhaust system provides the air/fuel ratio. This sensor calculates the amount of oxygen present in the exhaust gases and passes that information back to the ECU.

Once the EFI ECU has figured out what to do after calculating and interpreting data from the input sensors, it controls other output actuators such as the fuel pump control electronic mechanism, radiator thermo-fan(s) and of course the fuel and ignition systems. The fuel injectors are told when to open and how long they should stay open. The longer the injectors stay open, the more fuel flows into the engine (this is known as the injector's pulsewidth). The ignition timing is calculated and then the ignition system's igniters are sent a signal at precisely the correct time to tell the coil to supply a spark through the lead and into the engine.

Under cruising conditions, or part throttle, an air/fuel ratio near the 'stoichiometric' level of 14.7:1 is maintained to aid fuel economy and throttle responsiveness in what is commonly known as 'open loop' mode. Under minimal throttle conditions, when slowing down etc., the EFI ECU maintains an air/fuel ratio that is incredibly lean, near 16 or 17:1 (or more), to further aid fuel economy.

The great advantage of an EFI system is that the EFI ECU knows how to provide maximum performance and drivability for any and all conditions that the engine may experience. From full throttle up a steep hill to zero throttle down a steep hill, the EFI ECU can provide you, the driver, with the most power possible.

For a typical Mini EFI conversion, the EFI ECU should receive information from the following sensors:

* A throttle position sensor that tells the computer how hard your foot is on the accelerator pedal.
* A crank angle sensor that basically tells the computer where the pistons are in their travels.
* A knock sensor which detects any sign of detonation (pre-ignition or 'pinging') which is where the air/fuel mixture is exploding violently inside the combustion chamber instead of as a controlled progressive brurning.
* A Manifold Absolute Pressure (MAP) sensor which measures manifold vacuum (or boost!).
* The engine speed in revolutions per minute, which, among other functions, informs the ECU whether or not the rev limiter should be invoked.
* An oil pressure sensor as an emergency input, if the oil pressure is too low, some EFI ECUs actually turn the engine off after triggering a warning to the driver to restrict engine damage.
* An engine temperature sensor to let the ECU know if a cold-start function is required where the idle speed is increased along with different fuel and ignition settings are used until the engine has reached a normal operating temperature.
* An oxygen sensor that is plumbed into the exhaust manifold that examines the exhaust gases leaving the engine and informs the ECU what the air/fuel ratio is.
* Many other input sensors that can be used include the temperature of the intake air (especially important for a Mini using forced induction), a sensor indicating which gear you have selected and many more I don't have room to list.

The parts required for a typical EFI installation:

Starting from the fuel tank(s), fuel is pumped by a small fuel pump (known as a 'lift' pump) through a high-quality fuel filter into a cylindrical container called an anti-surge tank (which is also called an '(anti-)swirl pot'). It is vitally important to maintain an even flow of fuel to the engine, as forces from accelerating, braking and cornering can interrupt the flow of petrol through the fuel system causing the EFI ECU to receive incorrect data upsetting engine performance (lean mixtures for a very short period of time etc). Fuel is then pumped from the anti-surge tank into the fuel rail mounted close to the intake manifold preferably through another fuel filter. This main fuel pump should be able to supply petrol at high pressure (45+ psi) for the amount of horsepower your engine may make. Don't get sucked in by the person trying to sell you a fuel pump that is way too powerful such as a Bosch 'MotorSport' or VL Turbo Commodore pump. All they do is circulate too much petrol through the fuel rail, heating the petrol up leading to a lack of power. Once the petrol has reached the fuel rail, it sits behind the injectors waiting for them to open and flow into the intake manifold. The amount of pressure through the fuel rail is controlled by a fuel pressure regulator at the end of the fuel rail, which delivers unused petrol back through a different fuel line into the anti-surge tank to be used again.

The air flowing into the inlet manifold is controlled by a throttle body, which is basically a carburetor without the fuel delivery system and all the associated restrictions on air-flows that they provide. Mounted either in or just after the throttle body are the fuel injectors themselves and their wiring etc. I can't stress enough that all components used must be of the highest quality to ensure safety, legality and reliability as well as performance. Remember that you only get what you pay for.

Two possible EFI installations for your Mini:

There are two main types of EFI installations that could be used on Minis. Forget the UK Rover Mini injection systems, they are crude, inefficient and downright nasty. I would recommend you steer clear of them.

The most effective EFI conversions for a Mini use a cylinder head with 4 intake ports such as an Arden or Weslake 8- port head. Alternative heads like a BMW K1100 motorbike 16-valver or a KAD or Jack Knight Twin-Cam 16-valve unit would also be ideal (although price is ultimately the limiting factor). With any of the above cylinder heads, the injection system can use two Weber DCOE-type throttle bodies mounted in the same way as if carburetors were used.

If using a 5-port cylinder head then how about trying something different? Using a Weber 45 DCOE inlet manifold, have the inlet manifold's runners remade to point upwards towards the bonnet instead of back towards the firewall (you'll have to the runners cut and re-welded). Use an IDA (down-draft) throttle body with four injectors mounted around the throttle body and with a nice big air filter poking out through the bonnet, it should look pretty mean too. If non-turbo Mazda rotary engines can use IDA throttle bodies, why not us?

With four separate intake ports, the EFI can be run sequentially where the injection of the petrol takes place in each inlet tract just before combustion. With only two intake ports from a 5-port cylinder head, the EFI is run in 'group fire' mode where all the fuel is injected at the same time. This means that the air/fuel mix remains unburnt for two of the cylinders for a short time while the inlet valves are closed allowing the speed of air/fuel mix to slow down resulting in a slightly less efficient combustion process. Don't get me wrong, a 5-port with 'group-fire' EFI is fine, it's just that a cylinder head with 4 intake ports and sequential EFI is the ultimate in performance IF money is no object.

There are several after-market programmable EFI computers that are suitable for Minis, the MoTeC M4 or M48 computers are excellent for the serious racer. The Autronic, EMS, Wolf 3D, Haltech and MicroTech range of products are also suitable and quite easy to setup.

For more details or more advanced information, pictures or examples of EFI conversions check out the following websites or see me at a meeting:

For MoTeC products: https://www.motec.com.au
For EFI equipment: https://www.injectionperfection.com https://www.fueltronics.com.au
For the Haltech range: https://www.haltech.com.au
For the EMS range: https://www.pem.com.au/enginemanagement.htm

Hope you had a good read.

I read the above literature and found it quite interesting. I have another article about a programmable ignition. This article focuses on the FORD Electronic Distributorless Ignition System (EDIS) and the Megajolt Lite Jr (Megasquirt). The Megajolt unit is is a fully programmable, stand-alone ignition controller designed to control a Ford EDIS 4, 6 or 8 crank-fired ignition module.

From reading these two articles and others, I think I can narrow my focus to the CFI ECU on the '85 LTD (possible replacement if required) and a programmable ignition unit that may be able to piggyback onto the existing CFI ECU. The possible outcome from this research is to determine if there is a way to vary the ignition timing to set the operating mode of the FI GW so that it can be more or less responsive by advancing or retarding the timing. I think this is basically what happens with more modern bikes with the different operating modes such as in the case of my son-in-law’s Moto Guzzi (rain-touring-sport).

The EDIS unit is interesting in that it can be used with a wasted spark ignition system such as that on the GW. The Minis are also using these units and this leads me to believe that there are some similarities between the GW and the Mini that may provide information that could provide a way ahead. I have viewed You Tube videos on these units as well. Some of these videos are primarily about improving the operating performance of a 4 cylinder engine.

A wasted spark ignition system is one where two spark plugs fire at the same time, separated by 360 “cycle degrees” of a 4-cycle engine, so there is no need for synchronization with the camshaft.
This means that one cylinder has its spark plug firing during the valve overlap period near top dead center, but because the pressures are so low and the charge is diluted by the exhaust gases, no ignition occurs. This spark is 'wasted' on a cylinder that isn't firing, and EDIS is referred to as a 'wasted spark' ignition system.

Wingadmin over on GWDocs provided this information regarding the different trigger wheels between GL1500 and GL1200.

The EDIS system uses a crank trigger wheel that calculates the exact position of the crankshaft. The missing tooth on the crank trigger wheel indicates the exact position of the crankshaft to the EDIS.
The GL1500 uses a trigger wheel that doubles as a crank shaft position sensor – has a missing tooth.

The ignition computer on the GL1500 looks for that missing pulse during the rotation, and by doing so figures out what position the engine is in so it knows when to fire the plugs. That’s why the GL1500 takes a revolution or two to before it starts – the computer needs to work out the engine position before it can fire off the plugs. This is similar to the EDIS requirements.

The GL1200 has a trigger wheel that is used specifically to detect variations in crankshaft speed (correlates to engine speed) and has no missing tooth. This is the Ns sensor. The 1985 Limited Edition and 1986 SEi use a camshaft angle sensor (GR/GL) in place of a crank angle sensor to detect and determine the exact angular position of the crankshaft. The GR/GL sensors are on the back of the right cylinder.

I think my next determination is correlating the 1985 LTD and 1986 SEi fuel injected sensors against the requirements for an automotive FI system.

The ignition timing is electronically controlled by the Computerized Fuel Injection (CFI) electronic control unit (ECU) that receives input signals from the crankshaft angle - Ns, right and left intake pipe pressure - PBr/PBl, throttle - Oth, camshaft angle - GR/GL (right/left), and coolant temperature - TW sensors.

The CFI ECU gets signals from the various sensors to:

a. get fuel to the cylinders in the correct amount and at the right time through the injectors;
b. determine the optimum ignition timing based on signals received from the various sensors;
c. controls ON/OFF of ignition current;
d. controls fuel pump; and
e. indicate faulty system or components through a self-diagnostic system and has fail-safe functions.

Armed with this information I can do some more research to further my understanding.

More to follow. Hope you have a good read.

Cheers

Interesting read.

My brain hurts.

very interesting read ...and ive looked at this stuff before quite hard ...in strictly a why doesnt it work well way ..there have been many try FI big time on oldwings and most just dont perform well ...to me it came clear to see that in a perfect charge of 14/1 ratio for a motor to run the best ...seem EFI contaminates on the one part and really dose nothing on the 14 part the air ....over 90% of everything...on my bike witch is weber carbed and the carb is highly modified and dial in well ...i can feel changes in the way it runs by the differences in the make up of the air its bringing into motor ...theres no doubt in my mind that if one could control the monitoring of the air content to fuel input ..you would come up with a completely better system than the ones there making today ...theres dry air... there moist air ..there hot air ..theres cold air.... as basics things and many combination of it all ...the gas is relatively the same ....proof of this comes in many ways ...as in intercoolers that make air charge colder and more dense ...turbos and supers that bring more air than the motor will bring on its own....

it is very hard to get away from the point of how important the air is ..on a NA induction system you have total metering of motor intake of by the motor ...a well dial in carb and i mean well dial in is also have total metering of gas input....to have this a carb has to be devoid of epa add on junk that messes with the simplicity of a strait carb ..no vacuum control devises other than the motor does naturally....throttle body or in carb case throttle plates are air control so carb or EFI use the same thing ...on a carb all this is done without one sensor period ...im speculating on a well dial in set up of a strait carb dam near everything is almost perfect ...and only the content of the air is not accounted for ....if all the sensors were on the air content before the motor instead of monitoring what has already happen after the burn ..im thinking this woul beat the present EFI totally ...my bike will run with any out there as is ...and also runs like it is EFI ...why cause it dialed in great ...id like to see EFI system really succeed ...very interested in this thread ..no slam here just opinion

It's interesting how at the front of every/most OEM/aftermarket service manuals there is a plug colour chart. The powers to be advocate a lite chocolate brown colour for the spark plugs - 2 or 4 stroke. The reality is that oil/fuel systems are set up from the get go to be black indicating a rich fuel mixture. The OEM does this to protect us from ourselves, an engine that has a "rich" fuel mixture is less likely to "grenade" because of the rider/driver - keeps OEM liability for warranty and such to a minimum as well.

I encountered this on my older Yamaha snowmobiles. I could adjust the oil mixture such that I achieved a spark plug colour similar to the spark plug colour chart. Had two identical machines - left the wife's alone and did a comparison. Less oil spewing out the pipes, better performance and fuel economy.

As Joe mentions air is a key element to the efficient/economical operation of the engine. It would be nice to have a fuel/ignition system that could compensate accurately for differing air quality. EFI as it is does this very well for the size and cost that OEMs now face, and lets not forget the environmental issues that hamstring good engineering. It would be nice to treat the incoming air (much like an AC system) and provide a consistent flow/quality to the engine but the cost and size of such a system would probably be prohibitive.

What I am trying to understand with this thread is how the components interrelate in layman's terms, and if there are any possibilities for aftermarket, or even car related, component(s) that can be used to augment/improve/substitute to keep these older FI models on the road. My biggest concern for my '85 LTD is the CFI ECU. I think a work around for the various sensors is well underway and most have been addressed.

The information on the FORD EDIS and Megajolt Lite Jr (megasquirt) may be of interest to those who tinker with the carb model 1200s.

It's a great learning experience and when you are retired you need to keep the old brain box engaged and challenged.

More to follow.

Cheers

Been actively researching this issue and have learned a lot about the '85 LTD and '86 SE-i fuel injection system.

Even thought the service manuals mention that the Ns sensor (crankshaft sensor) and the Gr/Gl sensors (camshaft sensors) signals are used for both fuel injection and ignition timing, there are those out there that put forward that the Ns sensor is solely used for ignition timing and the Gr/Gl sensor is for fuel injection. I leave this out there for you to make your own decision on which does what to whom. If I get more definitive information, will post here.

I did a test today regarding the PB sensors (pressure barometric) and how the system interacts. I read where the system only needs one of these sensors to operate. I decided to check on this and disconnected each - one at a time with the bike running. As mentioned the bike ran with only one PB sensor hooked up. This also is a good way to determine if the PB sensor(s) need replacing. I understand that this applies to the Gr/Gl sensors as well.

I had a look at the Gr/Gl sensors and found these were out of adjustment. The air gap is 0.024" and mine were about 0.125". I adjusted them up with no difficulty. The folks over on the CX500-650 forum have a work around replacement for this sensor. It is an SMP LX579 sensor. It is slightly larger, but can be adjusted to fit.

The PB sensors are obsolete as most know; however, the folks over on the CX500-650 forum have found that a Suzuki PB/MAP sensor will work on place of the GW PB sensors and are extremely close in specification as well. The sensor is a DENSO 15620-35F00.

The bad news for myself is I was hoping that I had a bad PB sensor and or Gr/Gl sensor as these are easier to get at and replace with aftermarket parts that are already identified. Not to be so lucky.

Checked the TPS readings this afternoon and the resistance was at 0.26 k and should be between 4 and 6 K. Manual mentions that if the resistance is not at spec values to replace. Since heat is the enemy of any resistance, I would expect that when the bike is operating and quite warm, the reading may even be less. I am now in the hunt for a new or new to me TPS so I can get the bike operating correctly. It is running and I have ridden it, but the experience is a bit disconcerting. I will have my brother spec the TPS in the bike I have in Ontario. A direct replacement will be good. Should this not pan out I will be going to plan B that will be a Honda auto TPS or a BEI-Duncan TPS from Mouser Electronics.

Regarding a possible replacement for the ECU on these FI models, have been looking at the Megasquirt and how it interacts with new FI systems and possibly already installed systems. Don't know much about the design as of yet; however, lots of information available on these forums and elsewhere. I do like the aspect that if using a unit such as the Megasquirt, you can change settings to better (hopefully) tune the system.

More to follow.

Cheers

Resurrecting this thread because I now have a bit more time to get back at this issue.

Now that I have a lot of the work on my '85 LTD done, and having made the decision to do the rings on the engine, pretty much the last engine work to do, I am off thinking about a replacement for the ECU again. I keep track of the various threads regarding this and there are several over on the NGW forum. I have mentioned that this is preliminary at this point, but one needs a challenge.

I am embarking on this research because I have several electronic parts I have had to replace/work around, and the equipment/parts on this bike are not getting any younger. As has been mentioned here and on other forums, replacing old with old is still old and used. Even NOS has a shelf life.

There are a few aftermarket ECU units around, but as I have mentioned in other posts on this thread the Megasquirt units seem to be the unit of choice.

Staring to put together a binder with the information on these units and how it operates. From initial reading the only addition to the CFI system on the '85 LTD is an O2 sensor. Find an appropriate O2 sensor, drill and weld a boss on the exhaust, and should be good to go. Fortunately I have picked up a light duty stick welder that will aid in this.

I'm thinking it is going to be a two year research project because I am schooling myself in the nuances of the FI system such as how the system works. Have a basic idea, but need to get more specific.

I'm also thinking that there may be a good buy on a used Megasquirt unit in the near future, never can tell.

It has been mentioned in this thread that there have been many attempts, but not a lot of success in the EFI arena. Most of the threads I have been reading/perusing are about a change from carb to an FI system. This is by far the hardest part as there are lots of FI nuances that need to be addressed. Since I am dealing with an FI system, and just want a replacement part for the system, I should be better off. The bottom line is no ECU, no bike to ride.

Interesting subject, lots to learn. Cheers

Yes it is interesting always wanted to try but cost is way to much to play here ...I’m guessing parts that available to buy are made for much bigger motors and are not sensitive enough to handle a oldwing motor and it’s quick changes ..in reality carburetor and fi do the same thing ...and I was amazed how much I had to do to mod the carb to stay with the needs of the oldwing motor and not get out of wack ...lot of assuming here ..as I have experience with working with the fi parts ...

Have been reviewing the threads regarding FI, and as you mention, it is not inexpensive. There is the tuning that can drive one to distraction.

Most FI projects do not come to fruition, but in my case, I just want an alternative to the OEM ECU if it fails.

Saw some of your old posts over on NGW. You have been following the FI world for quite some time, Dan as well.

Cheers