FI light and turning engine off while driving
- This topic has 33 replies, 3 voices, and was last updated 5 days ago by .
-
Posts
-
-
Bike Model = : Hyosung GT250i: 2011:
My Hyosung GT250i (29,100 km; 2011) is experiencing the following problems:
1. While riding in 4th or 5th gear, the red FI light occasionally comes on for a few seconds up to 20 minutes, without any noticeable changes in handling. It eventually goes out on its own, but it always goes out when I slow down and shift down a gear. It never comes on when the bike is stationary (idling), so it’s impossible to run a diagnostic check while the bike is stopped. This has been happening for years, but it doesn’t affect the bike’s performance.
2. Since this summer, the engine stalls while riding. This happens unpredictably and lasts only briefly. You can restart it while coasting. No error is indicated by the FI light during this time. Idling is very unstable. The RPM fluctuates, and the engine stalls after a short time. It gets worse when the engine is warm.
What could be causing this, and how can these issues be fixed? Do they have the same cause, or are they caused by different issues? As for electrical problems, i’ve previously had a faulty speed sensor, the rear ignition coil, and the headlight relay.
-
These issues point to a possible of the following:
- Harness needs all connectors check for oxidization of the pins
- Check ECU for oxidization pins  (you can use contact cleaner on the harness) but never put liquids at the ECU itself, just blow the ECU pins with compressed air and let it dry fully on the harness before pluging stuff back in.
- Spray carb cleaner on on the throttle bodies to see if there is air leaks , the bodies have little o-rings that may have age-rotted ?
- ISCV (idle speed control) – Common but does affect idling and gear changes (momentary idle for rider to change gears ot twist throttle again)
- TPS Sensor  (use service manual to make sure its in spec, its on the forum as 250 EFi manual)
- Fuel Pump is waning (age) or strainer-mesh is clogged in up (triggers Fi when riding) ,
- If the LCD glass panel says 50mph / FI / 20mph / FI  0 / FI / while moving, its 100% to do with the pump and injectors.
- get Wynn’s Formula Gold Petrol (or extreme equivalent)Â (not RED-EX) , pour the whole bottle in the tank with maybe 3 bars of fuel , rider until its nearly empty , you want these bottles to make their way down the whole fuel system to clean any stubborn accumulated deposits
- Injectors waning (age?)
- Check rtelay for fuel pump and replace it  (or if the pump uses a 30A fuse , check it ) == It is up to Hyosung to use a 30A fuse or 20A/40A relays on these bikes for fuel pumps, they updated the harness a lot across all EFi machines.
-
-
Do i have to synchronize the throttle valves?
I would not touch the butterfly valves if they are still original (nobody touched them before you), as it could be hard to re-balance it if you’re not sure what to do. Normally the factory sets up and discourages anyone from touching them.  If in doubt , have a spare back up throttle bodies from a crashed donor bike, just to rule things out.
-
I’ve now separated the airbox from the throttle body. One of the rubber connecting sleeves had a tear of 2–3 centimetres along the edge. It was starting to crumble. I’ve ordered new ones, but they won’t be delivered for another 10 days. I cleaned the connector pins, even though they all still looked new and in good condition. I didn’t dare touch the ECU connector, though. I also cleaned the ISC solenoid. Some black gunk came off, but it didn’t seem that bad to me. I can now access the throttle body. What work should I do on it? I have plenty of time before the rubber parts from Korea arrive.
-
-
While the airbox is apart, split the throttle bodies carefully and inspect the O-rings, there is 4x of them (middle x2) and 2x to the engine cylinder heads
Then when the throttle bodies are apart , use carb cleaner all over them  (remove sensors first!)
Least you want to make sure the intake system is pristine so there is no macro air leaks , making the idle Speed controller work too hard or throttle possibly getting sticition (or jammed from dirt)
For sensors, their connectors (wires) and the sensor pins should be cleaned with contact cleaner and dried up for 24hrs at least if its cold out doors.  Now use this time to check the pins for oxidization , as too much oxidization can affect how precise the sensors can send signals back to the ECU. A badly corroded pin can easily jump from factory 0.5 ohm to 3 ohms, that’s enough to panic the ECU, it’s just an example.
Remove the ET sensor carefully (Temp Sensor in front cylinder) ,  the pins will need to be cleaned. If the ECU asks the sensor what temp engine is, and it gets 50 ohms (100 degrees celcius) , it might go haywire when the engine is actually 65 degrees , it was the oxidized pins and connector plug fouling the ECU with incorrect values. (these values are just examples, real figures will be in the service manual)
The service manual will tell you if the sensor is good or not with a meter to test and you use a hot glass with thermometer. If the glass bowl of water says 60 degrees , you need help with someone holding the sensor TIP in to the water (black body must not touch water) , you will probe the 2pins , it should say  (example) 2,000 ohms , the manual says 65-70c should be 3,000 ohms etc, you will know if you want to clean the sensor or replace it if it is failing.  The ECU does depend on temp sensors.
Also your airbox will have a TEMP sensor (Air Temperature) as hotter air has less oxygen, so it will tell the ECU how much fuel goes to the injectors, so the engine doesnt get too rich or too lean.   Another “temp sensor or heater element” is the lambda sensor (hot exhaust gases , it will warm it up) but not every modern bike uses this , so we just call it Oxygen Sensor instead, it will sense oxygen in the pipes (too rich or too lean)
All these separate parts affect how well the bike idle, runs , and rides. So do one thing at a time and the manual will help you test each part to see if they are still in spec.
-
Today I ordered O-rings for the sealing surfaces and started removing the throttle body and the fuel injection unit. What I just can’t seem to do is disconnect the throttle position sensor connector. How the heck do you do that? Where’s the latch mechanism I need to release? It’s the sensor with just one screw.
-
-
-
-
-
One of the two rubber connectors between the airbox and the throttle body is damaged and needs replacing. I’ve ordered and paid for them, but it seems I’ve fallen for a fraudulent website. The rubber connectors are no longer manufactured and are sold out everywhere. If anyone knows where to get hold of them, I’d be very interested On the other hand, there might be a way to replace them with parts from other manufacturers. Perhaps someone will have an idea after looking at the sketch with the approximate dimensions (in millimeters) and the photo. Someone on eBay is offering 5 pieces, but won’t ship them to Germany. It seems to be the last offer available worldwide.
-
-
I sell them below
https://www.ebay.co.uk/itm/257243814986
They come as SHORT HEIGHT (from carb model) or Tall Cone style = Makes no difference to EFi ,  if ebay won’t let you ship them (I always enable global shipping) it is up to ebay if they themselves will ship to you as we use PitneyBowes (ebay owned couriers for global orders)
Otherwise, send an email for a custom quote and we will use the UK Postoffice to your local country post likely DeutschePost
-
Since I was unable to find replacements for the damaged rubber fittings, I reassembled the machine using the old ones. I cleaned the throttle bodies and the ISC sensor, replaced the fuel injection unit and the air filter, disconnected all electrical connectors, cleaned them, and sprayed them with contact cleaner; I removed the fuel pump and cleaned its filter; and I calibrated the regulator and the IAP sensors. There was no corrosion or significant dirt anywhere. Except for the throttle body connectors to the airbox, all parts were intact and looked good.
The bike starts up, but after a few fluctuations, it quickly stalls again while idling. Above 4,500 rpm, it revs willingly, smoothly, and responds to the throttle. Below 4,000 rpm, it shows slight jerking and sluggishness. It responds sluggishly and with a slight delay to twists of the throttle grip and sounds weak. I didn’t ride it, since the reassembly was only temporary.
What’s new is that it now displays error code C41 after stalling. The fuel pump is making operational noises; I replaced the fuel pump relay: no change. Today I’m going to try cleaning the injectors with EFI cleaner added to the gas. I’m not holding out much hope, but what else can I do?
As I’ve been asking around, I’ve now been told that every component and every sensor could be the cause of the problem. Many of these are very hard to find as replacement parts—for example, the ECU or the rubber fittings I mentioned earlier, but also some sensors.
The motorcycle is starting to feel more and more like a “disposable motorcycle” to me. It runs fine at first, but as soon as more complicated problems arise, you might as well just get rid of it. There are no replacement parts, and the mechanical work between the cylinders is impossible without custom-made tools—and it’s a real pain. You don’t see this motorcycle around anymore, and I haven’t seen its popular sister model, the GV250i, in a long time either. I haven’t met anyone who’s said, “I had that problem once, and this is how I fixed it.” People don’t repair them; at best, they strip them for parts or send them to the scrapyard. And I’m slowly starting to consider doing the same.
<i>Translated with DeepL.com (free version)</i>
-
Since I was unable to find replacements for the damaged rubber fittings, I reassembled the machine using the old ones. I cleaned the throttle bodies and the ISC sensor, replaced the fuel injection unit and the air filter, disconnected all electrical connectors, cleaned them, and sprayed them with contact cleaner; I removed the fuel pump and cleaned its filter; and I calibrated the regulator and the IAP sensors. There was no corrosion or significant dirt anywhere. Except for the throttle body connectors to the airbox, all parts were intact and looked good.
The engine starts up, but after a few fluctuations, it quickly stalls again while idling. Above 4,500 rpm, it revs willingly, smoothly, and responds to the throttle. Below 4,000 rpm, it shows slight jerking and sluggishness. It responds sluggishly and with a slight delay to twists of the throttle grip and sounds weak. I didn’t ride it, since the reassembly was only temporary.
What’s new is that it now displays error code C41 after stalling. The fuel pump is making operational noises; I replaced the fuel pump relay: no change. Today I’m going to try cleaning the injectors with EFI cleaner added to the gas. I’m not holding out much hope, but what else can I do?
As I’ve been asking around, I’ve now been told that every component and every sensor could be the cause of the problem. Many of these are very hard to find as replacement parts—for example, the ECU or the rubber fittings I mentioned earlier, but also some sensors.
-
-
Now it won’t start at all and alternates between displaying C41 and C25. I replaced the rear ignition coil and the C25 error has gone. But it still won’t start. Now it’s showing C41 again. Today I wanted to remove the injectors, but there are those pesky connectors again. How do you unscrew them?
-
-
Usually the grey slider stays inside the connector and you press down to pull the plug out of the injector, though again like other connectors they need a careful approach so we don’t break the tabs (it is a good thing so they don’t vibrate out immediately when riding)
-
-
My GT650R 2013 has the FI light and on the triple key it flashes 10-1-3-8. I only just worked out how to message. Can I plz get a little assistance to sort out the issue. Please, thank you and TA?
This topic was for the GT250 , you could start a new topic if you’re stuck but before you do that , go to the forum first and get the 650cc manuals we posted for download, I uploaded every 650 manual i could find, they usually explain the error codes for you.
Regards -
New injectors and an idle speed control unit arrived today, so I can carry on. How do you get the injectors out of the bracket once it’s been unscrewed? You can turn them back and forth a bit, but you can’t pull them out. Is there a safety clip or locking mechanism?
-
-
-
It hurts to realise you’ve been daft. After cleaning the injectors, replacing the idle speed control valve, replacing the rubber grommets between the airbox and the throttle bodies, replacing the fuel pump relay, removing and cleaning the throttle valves, fitting a new ignition coil for the rear cylinder, calibrating the throttle valves and IAP sensors electronically, etc., the bike started up yesterday evening, idled steadily for over 10 minutes and responded to the throttle, revving up and then settling back into a steady idle… and displayed C41 the whole time. I switched the engine off and then it wouldn’t start again, even though it was warm, with C41 showing once more. The same thing happened this morning. It wouldn’t start and displayed C41. I then connected a charged car battery in parallel. The engine started immediately, with no error message. My battery had simply become too weak and could no longer be charged sufficiently. The fuel pump was running, and the starter motor was turning, but there was no spark or the spark was too weak. The ECU interprets this as a fault in the fuel injection system and displays C41. As a result, you end up looking in the wrong place. Conclusion: a new battery, then I’ll be in touch again.
-
-
Thank you very much for your help.
I’ve fitted a new battery and my motorbike is running again. The idle is steady, whether the engine is cold or warm. It no longer cuts out whilst riding and doesn’t display any FI error messages either.
Looking back:
1. The biggest difficulty for me was disconnecting the sensor connectors and also those of the injectors. They differ from the usual multi-pin electrical connectors and are practically different for every component. You don’t want to risk breaking anything because you don’t know how to get hold of replacements. The cramped space between the cylinders makes the whole thing a nightmare. Some areas are inaccessible with standard tools.
2. Rubber grommets that are no longer available can be reproduced using 3D printing. There are ready-made templates available for this, which are shared free of charge. (Bambu) Writing the programmes yourself – I used OpenSCAD – takes less time than searching for the parts online. The petrol- and oil-resistant, heat-tolerant and elastic materials are available, and there are hobbyist 3D printing shops just round the corner.
3. When faults are unclear, there’s a concern that the ECU might be faulty. The Daewoo one – like many other parts – is no longer available from spare parts suppliers. If it really is broken, there’s no need to give up on the motorbike. There are companies that repair them. This is said to take 2–3 weeks and cost about the same as a new one.
4. I’ve been told that you can convert an EFI model back to a carburettor model. The EFI models have the same cylinder heads as the carburettor models. If you don’t have a carburettor model to strip for parts, the Hyosung wiring loom would be the most important item. Everything else can be purchased as generic parts if Hyosung does not supply spare parts. -
I prefer carb models , less stress BUT it means you have to keep the carbs clean all the time and the intake pipe rubbers need spares.
EFi is good for “snappy” throttle and fuel management , and we have metal intake pipes!
If you ever get hold of a carb model that is crashed , buy it as a donor and rebuild all its carb parts , then when you are ready , transfer everythingg over (for your EFi bike not even the tank or stator or air box or speedometer is compatible with carb models)
If you keep it EFi, the best investment is Ester Oil , Cleaning once a while with WYNNS FORMULA GOLD product , a true MOSFET regulator, your ECU will last longer! , install a volt meter to keep an eye but you need to find a way not to cut wires on the harness, the volt meter should be its own harnesss to the battery with a ON/OFF switch at the handlebar , that’s it.  Invest in good japan coils or get new OEM Hankuk/Daewoo Korea coils as spares  , don’t get unknown ones unless you trust them , we don’t even sell unknown coils for EFi anymore, it’s all Japanese only, then use NGK caps , Laser Plugs  (not IX ones) – We should have a good healthy sparking system
BMC air filter in italy is OK if you keep the DB killer inside exhaust and exhaust can is about 400mm long , then it wont lean out at higher speeds, least you don’t spend money every 5-10k miles replacing stock filters when you can get a better free flow lifetime filter.
Ofcourse good brakes and tyres are more important!
-
The whole hassle is starting all over again: the bike wouldn’t start, even though the battery was replaced a week ago. It started straight away when I jump-started it from the car battery. Voltage at idle (1600 rpm) is 14.2 volts, and at 6000 rpm it’s 14.1 volts! The regulator is noticeably warm after a ride. Where could the fault lie?
The FI light comes on occasionally whilst driving. Nothing happens in town traffic with varying revs. After accelerating and settling into a constant speed, the FI light comes on. Not always, but often. It then goes out again when you shift down to lower gears. When driving steadily in higher gears, it stays on for 20 minutes or more.
Although the system displays code C41, the problem appears to be electrical in nature, as when jump-started with a car battery, the engine starts immediately and no fault message is displayed. -
-
-
FI = Fuel Injection System
=> Pump , Relays , Injectors , Coils , Caps , Plugs or connectors losing signal due to oxidized pins ,  –
Sometimes a full bottle of Wynns Formula Gold Petrol inside the tank helps clean things up , if nothing changes , then it is electrical faults in the Injection System
Regulator is fine, it’s not part of the injection system.   The ECU will be the final hurdle , I can’t confirm if it is the fault or not but it can happen to a dodgy ECU (Daewoo ECU’s are just very sensitive) , it means now spending time with service manual to check the injection system parts to make sure they are within OEM values before thinking about replacing them or not , or it may need cleaning. The service manual usually has a procedure on how to test each EFi sensor.
-
- You must be logged in to reply to this topic.
- This topic has 33 replies, 3 voices, and was last updated 5 days ago by .
-
Posts
-
-
Bike Model = : Hyosung GT250i: 2011:
My Hyosung GT250i (29,100 km; 2011) is experiencing the following problems:
1. While riding in 4th or 5th gear, the red FI light occasionally comes on for a few seconds up to 20 minutes, without any noticeable changes in handling. It eventually goes out on its own, but it always goes out when I slow down and shift down a gear. It never comes on when the bike is stationary (idling), so it’s impossible to run a diagnostic check while the bike is stopped. This has been happening for years, but it doesn’t affect the bike’s performance.
2. Since this summer, the engine stalls while riding. This happens unpredictably and lasts only briefly. You can restart it while coasting. No error is indicated by the FI light during this time. Idling is very unstable. The RPM fluctuates, and the engine stalls after a short time. It gets worse when the engine is warm.
What could be causing this, and how can these issues be fixed? Do they have the same cause, or are they caused by different issues? As for electrical problems, i’ve previously had a faulty speed sensor, the rear ignition coil, and the headlight relay.
-
These issues point to a possible of the following:
- Harness needs all connectors check for oxidization of the pins
- Check ECU for oxidization pins  (you can use contact cleaner on the harness) but never put liquids at the ECU itself, just blow the ECU pins with compressed air and let it dry fully on the harness before pluging stuff back in.
- Spray carb cleaner on on the throttle bodies to see if there is air leaks , the bodies have little o-rings that may have age-rotted ?
- ISCV (idle speed control) – Common but does affect idling and gear changes (momentary idle for rider to change gears ot twist throttle again)
- TPS Sensor  (use service manual to make sure its in spec, its on the forum as 250 EFi manual)
- Fuel Pump is waning (age) or strainer-mesh is clogged in up (triggers Fi when riding) ,
- If the LCD glass panel says 50mph / FI / 20mph / FI  0 / FI / while moving, its 100% to do with the pump and injectors.
- get Wynn’s Formula Gold Petrol (or extreme equivalent)Â (not RED-EX) , pour the whole bottle in the tank with maybe 3 bars of fuel , rider until its nearly empty , you want these bottles to make their way down the whole fuel system to clean any stubborn accumulated deposits
- Injectors waning (age?)
- Check rtelay for fuel pump and replace it  (or if the pump uses a 30A fuse , check it ) == It is up to Hyosung to use a 30A fuse or 20A/40A relays on these bikes for fuel pumps, they updated the harness a lot across all EFi machines.
-
-
Do i have to synchronize the throttle valves?
I would not touch the butterfly valves if they are still original (nobody touched them before you), as it could be hard to re-balance it if you’re not sure what to do. Normally the factory sets up and discourages anyone from touching them.  If in doubt , have a spare back up throttle bodies from a crashed donor bike, just to rule things out.
-
I’ve now separated the airbox from the throttle body. One of the rubber connecting sleeves had a tear of 2–3 centimetres along the edge. It was starting to crumble. I’ve ordered new ones, but they won’t be delivered for another 10 days. I cleaned the connector pins, even though they all still looked new and in good condition. I didn’t dare touch the ECU connector, though. I also cleaned the ISC solenoid. Some black gunk came off, but it didn’t seem that bad to me. I can now access the throttle body. What work should I do on it? I have plenty of time before the rubber parts from Korea arrive.
-
-
While the airbox is apart, split the throttle bodies carefully and inspect the O-rings, there is 4x of them (middle x2) and 2x to the engine cylinder heads
Then when the throttle bodies are apart , use carb cleaner all over them  (remove sensors first!)
Least you want to make sure the intake system is pristine so there is no macro air leaks , making the idle Speed controller work too hard or throttle possibly getting sticition (or jammed from dirt)
For sensors, their connectors (wires) and the sensor pins should be cleaned with contact cleaner and dried up for 24hrs at least if its cold out doors.  Now use this time to check the pins for oxidization , as too much oxidization can affect how precise the sensors can send signals back to the ECU. A badly corroded pin can easily jump from factory 0.5 ohm to 3 ohms, that’s enough to panic the ECU, it’s just an example.
Remove the ET sensor carefully (Temp Sensor in front cylinder) ,  the pins will need to be cleaned. If the ECU asks the sensor what temp engine is, and it gets 50 ohms (100 degrees celcius) , it might go haywire when the engine is actually 65 degrees , it was the oxidized pins and connector plug fouling the ECU with incorrect values. (these values are just examples, real figures will be in the service manual)
The service manual will tell you if the sensor is good or not with a meter to test and you use a hot glass with thermometer. If the glass bowl of water says 60 degrees , you need help with someone holding the sensor TIP in to the water (black body must not touch water) , you will probe the 2pins , it should say  (example) 2,000 ohms , the manual says 65-70c should be 3,000 ohms etc, you will know if you want to clean the sensor or replace it if it is failing.  The ECU does depend on temp sensors.
Also your airbox will have a TEMP sensor (Air Temperature) as hotter air has less oxygen, so it will tell the ECU how much fuel goes to the injectors, so the engine doesnt get too rich or too lean.   Another “temp sensor or heater element” is the lambda sensor (hot exhaust gases , it will warm it up) but not every modern bike uses this , so we just call it Oxygen Sensor instead, it will sense oxygen in the pipes (too rich or too lean)
All these separate parts affect how well the bike idle, runs , and rides. So do one thing at a time and the manual will help you test each part to see if they are still in spec.
-
Today I ordered O-rings for the sealing surfaces and started removing the throttle body and the fuel injection unit. What I just can’t seem to do is disconnect the throttle position sensor connector. How the heck do you do that? Where’s the latch mechanism I need to release? It’s the sensor with just one screw.
-
-
-
-
-
One of the two rubber connectors between the airbox and the throttle body is damaged and needs replacing. I’ve ordered and paid for them, but it seems I’ve fallen for a fraudulent website. The rubber connectors are no longer manufactured and are sold out everywhere. If anyone knows where to get hold of them, I’d be very interested On the other hand, there might be a way to replace them with parts from other manufacturers. Perhaps someone will have an idea after looking at the sketch with the approximate dimensions (in millimeters) and the photo. Someone on eBay is offering 5 pieces, but won’t ship them to Germany. It seems to be the last offer available worldwide.
-
-
I sell them below
https://www.ebay.co.uk/itm/257243814986
They come as SHORT HEIGHT (from carb model) or Tall Cone style = Makes no difference to EFi ,  if ebay won’t let you ship them (I always enable global shipping) it is up to ebay if they themselves will ship to you as we use PitneyBowes (ebay owned couriers for global orders)
Otherwise, send an email for a custom quote and we will use the UK Postoffice to your local country post likely DeutschePost
-
Since I was unable to find replacements for the damaged rubber fittings, I reassembled the machine using the old ones. I cleaned the throttle bodies and the ISC sensor, replaced the fuel injection unit and the air filter, disconnected all electrical connectors, cleaned them, and sprayed them with contact cleaner; I removed the fuel pump and cleaned its filter; and I calibrated the regulator and the IAP sensors. There was no corrosion or significant dirt anywhere. Except for the throttle body connectors to the airbox, all parts were intact and looked good.
The bike starts up, but after a few fluctuations, it quickly stalls again while idling. Above 4,500 rpm, it revs willingly, smoothly, and responds to the throttle. Below 4,000 rpm, it shows slight jerking and sluggishness. It responds sluggishly and with a slight delay to twists of the throttle grip and sounds weak. I didn’t ride it, since the reassembly was only temporary.
What’s new is that it now displays error code C41 after stalling. The fuel pump is making operational noises; I replaced the fuel pump relay: no change. Today I’m going to try cleaning the injectors with EFI cleaner added to the gas. I’m not holding out much hope, but what else can I do?
As I’ve been asking around, I’ve now been told that every component and every sensor could be the cause of the problem. Many of these are very hard to find as replacement parts—for example, the ECU or the rubber fittings I mentioned earlier, but also some sensors.
The motorcycle is starting to feel more and more like a “disposable motorcycle” to me. It runs fine at first, but as soon as more complicated problems arise, you might as well just get rid of it. There are no replacement parts, and the mechanical work between the cylinders is impossible without custom-made tools—and it’s a real pain. You don’t see this motorcycle around anymore, and I haven’t seen its popular sister model, the GV250i, in a long time either. I haven’t met anyone who’s said, “I had that problem once, and this is how I fixed it.” People don’t repair them; at best, they strip them for parts or send them to the scrapyard. And I’m slowly starting to consider doing the same.
<i>Translated with DeepL.com (free version)</i>
-
Since I was unable to find replacements for the damaged rubber fittings, I reassembled the machine using the old ones. I cleaned the throttle bodies and the ISC sensor, replaced the fuel injection unit and the air filter, disconnected all electrical connectors, cleaned them, and sprayed them with contact cleaner; I removed the fuel pump and cleaned its filter; and I calibrated the regulator and the IAP sensors. There was no corrosion or significant dirt anywhere. Except for the throttle body connectors to the airbox, all parts were intact and looked good.
The engine starts up, but after a few fluctuations, it quickly stalls again while idling. Above 4,500 rpm, it revs willingly, smoothly, and responds to the throttle. Below 4,000 rpm, it shows slight jerking and sluggishness. It responds sluggishly and with a slight delay to twists of the throttle grip and sounds weak. I didn’t ride it, since the reassembly was only temporary.
What’s new is that it now displays error code C41 after stalling. The fuel pump is making operational noises; I replaced the fuel pump relay: no change. Today I’m going to try cleaning the injectors with EFI cleaner added to the gas. I’m not holding out much hope, but what else can I do?
As I’ve been asking around, I’ve now been told that every component and every sensor could be the cause of the problem. Many of these are very hard to find as replacement parts—for example, the ECU or the rubber fittings I mentioned earlier, but also some sensors.
-
-
Now it won’t start at all and alternates between displaying C41 and C25. I replaced the rear ignition coil and the C25 error has gone. But it still won’t start. Now it’s showing C41 again. Today I wanted to remove the injectors, but there are those pesky connectors again. How do you unscrew them?
-
-
Usually the grey slider stays inside the connector and you press down to pull the plug out of the injector, though again like other connectors they need a careful approach so we don’t break the tabs (it is a good thing so they don’t vibrate out immediately when riding)
-
-
My GT650R 2013 has the FI light and on the triple key it flashes 10-1-3-8. I only just worked out how to message. Can I plz get a little assistance to sort out the issue. Please, thank you and TA?
This topic was for the GT250 , you could start a new topic if you’re stuck but before you do that , go to the forum first and get the 650cc manuals we posted for download, I uploaded every 650 manual i could find, they usually explain the error codes for you.
Regards -
New injectors and an idle speed control unit arrived today, so I can carry on. How do you get the injectors out of the bracket once it’s been unscrewed? You can turn them back and forth a bit, but you can’t pull them out. Is there a safety clip or locking mechanism?
-
-
-
It hurts to realise you’ve been daft. After cleaning the injectors, replacing the idle speed control valve, replacing the rubber grommets between the airbox and the throttle bodies, replacing the fuel pump relay, removing and cleaning the throttle valves, fitting a new ignition coil for the rear cylinder, calibrating the throttle valves and IAP sensors electronically, etc., the bike started up yesterday evening, idled steadily for over 10 minutes and responded to the throttle, revving up and then settling back into a steady idle… and displayed C41 the whole time. I switched the engine off and then it wouldn’t start again, even though it was warm, with C41 showing once more. The same thing happened this morning. It wouldn’t start and displayed C41. I then connected a charged car battery in parallel. The engine started immediately, with no error message. My battery had simply become too weak and could no longer be charged sufficiently. The fuel pump was running, and the starter motor was turning, but there was no spark or the spark was too weak. The ECU interprets this as a fault in the fuel injection system and displays C41. As a result, you end up looking in the wrong place. Conclusion: a new battery, then I’ll be in touch again.
-
-
Thank you very much for your help.
I’ve fitted a new battery and my motorbike is running again. The idle is steady, whether the engine is cold or warm. It no longer cuts out whilst riding and doesn’t display any FI error messages either.
Looking back:
1. The biggest difficulty for me was disconnecting the sensor connectors and also those of the injectors. They differ from the usual multi-pin electrical connectors and are practically different for every component. You don’t want to risk breaking anything because you don’t know how to get hold of replacements. The cramped space between the cylinders makes the whole thing a nightmare. Some areas are inaccessible with standard tools.
2. Rubber grommets that are no longer available can be reproduced using 3D printing. There are ready-made templates available for this, which are shared free of charge. (Bambu) Writing the programmes yourself – I used OpenSCAD – takes less time than searching for the parts online. The petrol- and oil-resistant, heat-tolerant and elastic materials are available, and there are hobbyist 3D printing shops just round the corner.
3. When faults are unclear, there’s a concern that the ECU might be faulty. The Daewoo one – like many other parts – is no longer available from spare parts suppliers. If it really is broken, there’s no need to give up on the motorbike. There are companies that repair them. This is said to take 2–3 weeks and cost about the same as a new one.
4. I’ve been told that you can convert an EFI model back to a carburettor model. The EFI models have the same cylinder heads as the carburettor models. If you don’t have a carburettor model to strip for parts, the Hyosung wiring loom would be the most important item. Everything else can be purchased as generic parts if Hyosung does not supply spare parts. -
I prefer carb models , less stress BUT it means you have to keep the carbs clean all the time and the intake pipe rubbers need spares.
EFi is good for “snappy” throttle and fuel management , and we have metal intake pipes!
If you ever get hold of a carb model that is crashed , buy it as a donor and rebuild all its carb parts , then when you are ready , transfer everythingg over (for your EFi bike not even the tank or stator or air box or speedometer is compatible with carb models)
If you keep it EFi, the best investment is Ester Oil , Cleaning once a while with WYNNS FORMULA GOLD product , a true MOSFET regulator, your ECU will last longer! , install a volt meter to keep an eye but you need to find a way not to cut wires on the harness, the volt meter should be its own harnesss to the battery with a ON/OFF switch at the handlebar , that’s it.  Invest in good japan coils or get new OEM Hankuk/Daewoo Korea coils as spares  , don’t get unknown ones unless you trust them , we don’t even sell unknown coils for EFi anymore, it’s all Japanese only, then use NGK caps , Laser Plugs  (not IX ones) – We should have a good healthy sparking system
BMC air filter in italy is OK if you keep the DB killer inside exhaust and exhaust can is about 400mm long , then it wont lean out at higher speeds, least you don’t spend money every 5-10k miles replacing stock filters when you can get a better free flow lifetime filter.
Ofcourse good brakes and tyres are more important!
-
The whole hassle is starting all over again: the bike wouldn’t start, even though the battery was replaced a week ago. It started straight away when I jump-started it from the car battery. Voltage at idle (1600 rpm) is 14.2 volts, and at 6000 rpm it’s 14.1 volts! The regulator is noticeably warm after a ride. Where could the fault lie?
The FI light comes on occasionally whilst driving. Nothing happens in town traffic with varying revs. After accelerating and settling into a constant speed, the FI light comes on. Not always, but often. It then goes out again when you shift down to lower gears. When driving steadily in higher gears, it stays on for 20 minutes or more.
Although the system displays code C41, the problem appears to be electrical in nature, as when jump-started with a car battery, the engine starts immediately and no fault message is displayed. -
-
-
FI = Fuel Injection System
=> Pump , Relays , Injectors , Coils , Caps , Plugs or connectors losing signal due to oxidized pins ,  –
Sometimes a full bottle of Wynns Formula Gold Petrol inside the tank helps clean things up , if nothing changes , then it is electrical faults in the Injection System
Regulator is fine, it’s not part of the injection system.   The ECU will be the final hurdle , I can’t confirm if it is the fault or not but it can happen to a dodgy ECU (Daewoo ECU’s are just very sensitive) , it means now spending time with service manual to check the injection system parts to make sure they are within OEM values before thinking about replacing them or not , or it may need cleaning. The service manual usually has a procedure on how to test each EFi sensor.
-
- You must be logged in to reply to this topic.