Sam Arora
Forum Replies Created
-
Posts
-
Att Joe: Have you tried logging your IAP readings while running? Trying to think if we have this in common, does your problem disappear after disconnecting the IAP? Could you please help me setup a live data reading? My bike has a Daewoo ECU (08K002) and I have the VAG KKL cable. In the back seat, there is a 4-pn connector, but no 2-pin connector as mentioned in other posts. I appreciate your help!
Please let me know how the fuel strainer replacement works out for you. I am going to pull my filter out once I run out of this tank.
Att Joe:
Have you tried logging your IAP readings while running? Trying to think if we have this in common, does your problem disappear after disconnecting the IAP?
Could you please help me setup a live data reading? My bike has a Daewoo ECU (08K002) and I have the VAG KKL cable. In the back seat, there is a 4-pn connector, but no 2-pin connector as mentioned in other posts.
I appreciate your help!
Update:
With the throttle bodies balanced with a manometer, the bike is def running healthier. But the sputtering problem after warmup is still there! Today I took the bike for a run on the highway and had to stop at an intersection right after. At idle it sounded like one cylinder kept cutting in and out, jumping from 1600 rpm to 2000 rpm. Light turns green, and it struggles to go, until the rpms rise and it kicks back in and stays like that, until you have to come to a stop again.
Just like before, unplugging the MAP to rear cylinder fixed the idle stumbling/bogging, and I babied it back home. I’m going to pull plugs to identify which cylinder is misfiring, although I’m quite confident its the rear cylinder causing problems. What happens when the MAP is disconnected? Does it dump gas and richen up the mixture? Are these symptoms of a rich condition, or is it leaning out?
To build a manometer at home, I used the following:
- 20″ clear vinyl tubing
- flat thick cardboard/wood plank for the structure
- couple zap straps/zip ties
- Some high viscosity fluid (I used 10W-40 engine oil)
Take the flat piece of cardboard/wood and make equidistant horizontal lines across, with your favourite sharpie.
Drill holes on sides, so that you can secure the clear vinyl tubing to this board using zip ties.
Center the vinyl tubing on the board, making a U-shape (loop) at the bottom, and strap it to the board.
Use a syringe or funnel to pour your choice of oil into the tubing, until it sits at the desired level.
I’m having trouble attaching images to this thread, however there are lot of examples on Google, check out some images for inspiration, and good luck!
Update:
I connected the manometer directly to the throttle bodies and started it up. Rear TB was pulling more than the front, which meant that it had a stronger vacuum from the motor and needed more air, so I slowly opened up that TB butterfly until both cylinders matched. It idled at 2100 rpm. So I turned each throttle body down one by one until the idle sat at 1400rpm and it idled very well with both cylinders pulling same vacuum. Here, the idle stopper is set!
Moving onto on-throttle settings, the front TB was pulling more vacuum under throttle (needed more air), so I had to increase the tension on this cable until both TBs responded equally to throttle being pulled. Engine pulled equal vacuum (or close to equal) at idle and on-throttle now, so the cable tension is set!
Now I re-route the vacuum lines back into the ISC and re-introduce it into the air system. Bike starts up right away, idle settles down at 1500-1600, revs freely and seems happy.
Note: If your TBs are set from the factory, do not mess with them! If its already too late and the damage has been done, this method should get you 99% close to it. Use a good quality manometer and a cold pint of your favourite beer, have fun with it. Good luck!
Thank you for the instructions Marcel.
Currently, my bike idles nearly smooth at the following settings:
Front TB: slightly open
Rear TB: closed
If I move either of these a little, the misfires start taking place.
Connected a manometer with the given instructions and the results were not satisfying. The rear cylinder was pulling significantly more than the front and upon adjusting the TB settings on the running bike to bring them closer, the running situation got worse. Still couldn’t get the manometer to match on both sides and the rear cylinder ended up sucking some of the hydraulic fluid and burned it off. I gave up at that point and just wanted to ride back home from the shop. Tomorrow, I am going to try again by eliminating the ISCV, taking vacuum readings straight off the cylinders, because the bike idles just fine with the two vacuum lines blocked off and ISCV bypassed. I will post an update after.
Hi Joe,
Thank you for the update. I followed your instructions and checked out my ISC valve. I removed ISC from the airbox and turned ignition “ON”, it unscrewed itself completely and flung the parts because of the spring pressure. I put it all back together and re-installed it.
fyi, According to a Hyosung tech on Facebook, our bikes have one TPS on the ‘front’ throttle body if you look in between the two throttle bodies. It indirectly reads both TBs because the second TB is supposed to be synced to the first TB from factory (bad design but that is how it is). I zeroed out (closed) both the throttle bodies and started the bike (based off of ISC only). It started and idled rough, did not respond well to throttle. Then I bypassed the ISC temporarily, by blocking off the two vacuum tubes, to make the bike idle and respond to throttle based off of throttle body settings only (like it was before I found out the ISC bypass). With the front throttle body closed and rear throttle body slightly open, seems like we’re back in sync (or close to it) the bike idled well and responded to throttle like it should (I should just leave it here and enjoy the riding season, but curiosity is a bitch).
At this point, I lock the TB settings right there and introduce the ISC back into it. The bike starts, revs high for a few seconds and then settles down around 1600 rpm. Now I’m riding it normally, with some occasional sputtering/bogging when taking off from lights. It does not stall, idles well and I am givin’ her the beans.
Next plan is to finalize and fine tune the TB sync using a manometer (using a T-fitting with ISC vac lines) and checking ISC operation on/off throttle (I think my ISC is not responding fast enough when I go on throttle and try to take off).
Hope this helps!
Regarding your question about the fuel filters for our pumps, there are brand new replacements available on Ebay, that can be installed without replacing the pump. Check link below: https://www.ebay.com/itm/161494487889?fits=Make%3AHyosung&itmmeta=01HW3FJGZVNMV5P4P6M7RAW72A&hash=item2599d25351:g:3rUAAOSwDthiIWeq&itmprp=enc%3AAQAJAAAA0BLOBSeT%2BNNUM73lPj14WcgjCK%2BSphXINUci%2Fk8kwybi6TS9DAc%2BFkD8v8%2BjoXn9sNSyUnU7ntfpPPoKuOI7VkPbXzMBH%2BqrtXMQvrMZZ%2B%2Fof7QFWBFu1bnMQ%2BRWKian%2Fj3F6Yi1dQ8fjzg%2Fz32wmAP3HhJovy1fgjsc8r%2BGKtRJ4DR%2Ba%2FD3XAVCjopjY8mshXcGjzEHOcErST2oceAkzllwFcuLDwD65ARkU0dWcAMJ44hJfkuTHMGyMJpZob8Def6H6ljpQkiqW0kP2psfYdE%3D%7Ctkp%3ABk9SR4SQyu_gYw
I took those two pipes and plugged them into the ports next to the ISC. I had to reset the throttle settings and close both the plates because the idle was going too high from the ISC and previously set throttle settings. Now the bike starts up right away and idles around 1600rpm, but the cylinder that was causing problems earlier cuts in and out, making the idle bounce to 1800 intermittently. The bike is not okay under load, bogs sputters and cuts out. I think I have made some progress by bringing the bike back to factory setup, but also back to square one at the same time 😆
That is some good insight Joe. My bike is the 250 FI version. You’re right that I have two separate pipes running from the airbox into the engine side of the carbs. However, in my setup, the two nipples coming out of the ISC stepper motor are open and not connected to anything and the pipes coming from each carb are plugged into two separate nipples on the airbox that are blocked off from factory. Is this the same on your bike? (Did someone f up on my bike in the past?)
Basically, those two ports on the engine side of the carbs are blocked off at the airbox in my setup. The carbs are also cable driven, so there is independent adjustment possible on both. Due to this, both carbs can be at different positions at a certain rpm. While the bike is idling, and you change settings on each carb, you can hear the idle go up or down, rough up or smoothen out etc. To align them by ear, I zeroed out both carbs and started from scratch (the bike wouldn’t start at this point because there is no air getting into the cylinders) and then proceeded to open them up one rotation at a time on each side until the idle sounded healthy. The bike is running well for the most part right now with the IAPs plugged in, except some random bog/sputter when I open it up too quickly.
To fine tune it from here, I am making my own manometer using clear vinyl tubing, a long flat piece of cardboard, and some suitable fluid for the liquid inside. There are a lot of DIYs out there on how to make one at home, and its quite easy. It works off of vacuum and you plug it into the port on the engine side of the carbs to check which way the liquid is getting pulled more. It gives you a good visual of what’s going on in each carb/throttle body because doing it by the ear alone is inefficient and inaccurate.
This is what a homemade manometer looks like: (https://www.irv2.com/forums/attachment.php?attachmentid=112936&d=1448751314)
The voltage test checked out according to the instructions in the manual, so I came to thinking that sensor and wiring are good. My friend, who is a Honda technician, was hanging around around that time. I swapped the two IAP sensors around and problem stayed on cylinder 2! This guided us to think that something else is making the IAP sensor trip.
We had eliminated the possibility of vacuum leaks and fueling issues so fiddled around with the throttle body adjustment a little bit to adjust AFRs and the stalling/sputtering at hot idle disappeared. Idle came down to 1500 rpm. The issue has now moved to sputtering at take off, which disappears once the bike gets moving and goes above 5k rpm. Next move is to sync the throttle bodies (TBS) properly by using a throttle body synchronizer (manometer) to adjust throttle bodies at (1) idle and (2) 4000rpm. I will update you on how that works out.
If your throttle bodies are not in sync, engine may backfire, sputter, stall and misfire at different rpms, and this gets significantly worse as the engine warms up. That is one thing that you can check on your Hyosung if everything else checks out as should be.
Regards,
Sam
You’re right, I have two IAP sensors. The idle and low throttle sputtering disappears when I disconnect the right side IAP (IAP 2) and the FI light comes on. However, IAP 1 does not produce the same result when disconnected, FI light comes on and it ends up killing the engine anyway.
I will check the voltage on the sensor and the connector side soon.
It is hard to swap the sensors around because the sensors are in a very tight spot and requires removal of some fuel lines to access the 8mm bolt holding it in. It is a good idea though, and I will be trying it if the bike is apart.
I do have a VCDS cable (Blue FT32) that I use to scan my Audi, but I could not understand how I could use that cable to read data from my Hyosung.
Thank you for your input!
Regards,
Sam
Update: I received the new MAP sensor today and unfortunately the problem still persists! For these few days I have been riding with the sensor disconnected and it rides great! I am so confused, don’t even know what to check next.
Sam
Update: In my scenario, it was one of the MAP/IAP sensors. I disconnected them one at a time, and after disconnecting the one on the right side, my idle dropped down to 1500 and the misfires disappeared! Ordering a new one now. Part number is 28084560. Hope this helps someone! I will update again after installing a new MAP/IAP.
Hi,
Quick update on coils. The ohm readings are reasonably within spec.
Primary: (Recommended) 3.5 ~ 5.5 Ohm [3.1 Ohm measured]
Secondary: (Recommended) 20 ~ 31 K Ohm [32 K Ohm measured]
On to the engine temp sensor now.
Reading about your last attempt, I am assuming your bike is carbed. The symptoms that you have described could also be an issue with ignition timing. I am not sure how ignition timing is calculated in a carbed bike. Does your bike have an ECU? On a different note, these could also be symptoms of ISC lines being disconnected and throwing off the AFR.
I have sourced GV650 coils off of ebay, which are a little longer in size but have the same orientation of connectors and come with new plug cables and caps. (http://surl.li/sfsix)
I was unable to remove the temp sensor from the bike last night, for lack of a better tool. Once I get it removed, I want to check the voltage being produced by the sensor under different temperature settings and compare them to the default values given in the repair manual. Today I am doing a resistance test on my old coils and will update you on that soon.
Sam
Hi,
I have run into the exact same issue on my bike recently. I have new coils on the way, but also looking at diagnosing engine temperature sensor at the same time because the idle difference between cold start and warmup is very significant. Cold starts are super smooth and after warmup it struggles to stay alive and eventually stalls. Any update on your issue would be super helpful!
Regards,
Sam
