Matts_12GS Posted March 18, 2011 Share Posted March 18, 2011 Everyone, A friend of mine has this bike and is having difficulty troubleshooting the issue. Seems the bike is fine when cold, runs and works fine but about the time it comes to temperature it starts to stumble and eventually stalls. It has spark on both sides when it stalls, and the HES has been replaced. It seems to me like it's a coil thing since the temperature of the engine affects it but I'm otherwise at a loss. Anyone have any ides? Link to comment
Boffin Posted March 18, 2011 Share Posted March 18, 2011 Everyone, A friend of mine has this bike and is having difficulty troubleshooting the issue. Seems the bike is fine when cold, runs and works fine but about the time it comes to temperature it starts to stumble and eventually stalls. It has spark on both sides when it stalls, and the HES has been replaced. It seems to me like it's a coil thing since the temperature of the engine affects it but I'm otherwise at a loss. Anyone have any ides? I would suspect the O2 sensor, as this is ignored until the engine warms up and then becomes the main source of data for the Motronic. Very easy to diagnose - just disconect it. The connector is on the RH side, up under the nose of the tank. The Motronic detects the absence of the O2 sensor and runs on the base map, just like it does with a cold engine. Andy Link to comment
dan cata Posted March 18, 2011 Share Posted March 18, 2011 +1 on what Boffin said Dan. Link to comment
dirtrider Posted March 18, 2011 Share Posted March 18, 2011 Morning Matt If it has spark on both sides when it stalls that pretty well eliminates the coil (not 100% but puts the coil way at the bottom of the list anyhow) As mentioned above the 02 sensor would be the first place to start looking unless that bike has an early design (re unsealed) Techlusion fuel controller on it. If it has an aftermarket fuel controller on it that would be the first place I started looking. If it has a Techlusion on it then completely disconnect that or at least disconnect the black ground wire and the injector jumper pickup from the R/H injector harness. Some of the early Techlusion units would get moisture in them and cause a stalling problem like your friend is seeing (OK cold but over fuels after engine warm up). Link to comment
Syro Posted March 18, 2011 Share Posted March 18, 2011 Howdy! I experienced the same thing on my 1100RT '97.It actually turned to be the left spark cable which for some strange reason stopped delivering power as it should when got warm.I swapted mine with a used one and everything is just fine! Link to comment
Matts_12GS Posted March 20, 2011 Author Share Posted March 20, 2011 We're looking at this now but nothing certain just yet. Link to comment
notacop Posted March 20, 2011 Share Posted March 20, 2011 Using a heat gun or hair dryer on components can speed up the temp cycle and can help find the offending item. conversely putting a damp cloth or compressed air can cool things back down to prove the failure. Link to comment
Matts_12GS Posted March 21, 2011 Author Share Posted March 21, 2011 Ok, the O2 sensor was replaced with the part number in the parts archive. Seems the folks installing had to cut off the ends and solder them on to the existing connection. Anyways, seems that the sensor cured the problem for a while but it has returned. Any thoughts? I've not looked at it personally, just troubleshooting over the phone third hand. Link to comment
dirtrider Posted March 21, 2011 Share Posted March 21, 2011 Evening Matt If you are sure the connections were soldered that might be a problem. For an 02 sensor to operate properly it needs access to outside air, most 02 sensors get that outside air down through the wires running to it. If the wires have soldered connections that probably blocked the ambient air flow so the sensor can’t respond correctly. If you look a aftermarket replacements 02 sensors they come with posi locks or other crimp type connectors as that doesn’t block air flow. I guess a quick test is to run it with the 02 disconnected to see if that cures the problem. Link to comment
Matts_12GS Posted March 22, 2011 Author Share Posted March 22, 2011 I'll pass that word along. Thanks! Link to comment
dan cata Posted March 22, 2011 Share Posted March 22, 2011 Evening Matt If you are sure the connections were soldered that might be a problem. For an 02 sensor to operate properly it needs access to outside air, most 02 sensors get that outside air down through the wires running to it. If the wires have soldered connections that probably blocked the ambient air flow so the sensor can’t respond correctly. If you look a aftermarket replacements 02 sensors they come with posi locks or other crimp type connectors as that doesn’t block air flow. I guess a quick test is to run it with the 02 disconnected to see if that cures the problem. This is interesting... If it is so, don't the sensors get the air where the wires com out of it? I have noticed that in pics, they have some kind of heat insulator for ~ 10 cm's at the end that they plug into the exhaust, can't them take thai air trough there? Link to comment
dirtrider Posted March 22, 2011 Share Posted March 22, 2011 Morning Dan Some of the very early (1 wire) non heated 02 sensors got their outside reference air directly from the housing that surrounds the top of the sensor. Lots of those sensors had issues as the sensors were usually mounted in the exhaust below the vehicle where they also took in water and salt dust, and plugged with mud. On most the latest design 02 sensors the reference air comes down the wires or on some the sensor has a long rubber sleeve over the wire harness with a sealing bellows between the sensor top and that sleeve so they get their reference air down that sleeve. BMW mounts the 02 sensor very low and under the bike where water, mud, road dust and about everything else can get to it. That sensor wouldn’t last very long if it got it’s reference air from the top of the sensor. Link to comment
Jim Moore Posted March 22, 2011 Share Posted March 22, 2011 Ok, the O2 sensor was replaced with the part number in the parts archive. Seems the folks installing had to cut off the ends and solder them on to the existing connection. Anyways, seems that the sensor cured the problem for a while but it has returned. Any thoughts? I've not looked at it personally, just troubleshooting over the phone third hand. I've been riding with my O2 sensor unplugged for 80K miles. Tell him to give it a try. Link to comment
Secret Buzzard Posted March 22, 2011 Share Posted March 22, 2011 Don't discount a bad replacement Hall sensor. The guy in Key West from last year had the dealer put a new one in and then proceded to replace the rest of the bike piece by piece until he tried a known good one. Link to comment
Ken Lucius Posted March 22, 2011 Share Posted March 22, 2011 I'm the guy with the GS being discussed in this thread. My old login had disappeared as I haven't been on this forum since selling my RT a few years ago. Anyway, I'm back and appreciate all the input. I very well may have caused the problem with the new sensor by using heat shrink tubing over the external sheath as well as each individual wire. I didn't realize that it needed to breath through the wiring. I'll remove the heat shrink and see if that makes a difference. Results to follow... Link to comment
dirtrider Posted March 22, 2011 Share Posted March 22, 2011 I'm the guy with the GS being discussed in this thread. My old login had disappeared as I haven't been on this forum since selling my RT a few years ago. Anyway, I'm back and appreciate all the input. I very well may have caused the problem with the new sensor by using heat shrink tubing over the external sheath as well as each individual wire. I didn't realize that it needed to breath through the wiring. I'll remove the heat shrink and see if that makes a difference. Results to follow... Welcome Ken A couple of things not to do when replacing an 02 sensor— One is to not solder or otherwise block the wire strands. Two is to not pack the connector full of dialectic grease or silicone sealer. Either of the things above can lead to early 02 failure. Or at least an inop 02 or poor 02 performance. Bosch has a warning against soldering the wires on it’s universal 02 replacement install. Added: You might just disconnect the 02 sensor to see how it runs with it disconnected (won’t hurt anything). If it then runs OK NEXT try removing the heat shrink and solder connections. There is always the chance you have damaged the new 02 so even removing the heat shrink and solder might not cure your problem. Never use any type of silicone sealer on any of the 02 connections unless the silicone tube says 02 sensor safe. Certain silicone sealers can quickly poison an 02 sensor. Link to comment
4wheeldog Posted March 22, 2011 Share Posted March 22, 2011 Another day not wasted.......I learned something. Thanks. Link to comment
Ken Lucius Posted March 23, 2011 Share Posted March 23, 2011 Great info Dirtrider (and others). Earlier today, I vented the outside heat shrink tubing as well as the sheath that covers all of the wiring, plugged the connector back up and went for a ride. After 70 miles of combined city/highway riding, all seems to be well. The furthest I had gotten yesterday was a couple of miles before it would quit running. As was also recommended, I pulled the 5th fuse and did the throttle open-close (three times) routine before starting the bike in an effort to reset the Motronic unit. Tomorrow I think I'll cut the soldered joints out and crimp them in hopes that I got lucky and didn't damage the sensor. I may take a nice ride with it disconnected as well just to see how it runs, since that has served Jim so well. Thanks again for all the great input. Link to comment
Matts_12GS Posted March 23, 2011 Author Share Posted March 23, 2011 Great info Dirtrider (and others). Earlier today, I vented the outside heat shrink tubing as well as the sheath that covers all of the wiring, plugged the connector back up and went for a ride. After 70 miles of combined city/highway riding, all seems to be well. The furthest I had gotten yesterday was a couple of miles before it would quit running. As was also recommended, I pulled the 5th fuse and did the throttle open-close (three times) routine before starting the bike in an effort to reset the Motronic unit. Tomorrow I think I'll cut the soldered joints out and crimp them in hopes that I got lucky and didn't damage the sensor. I may take a nice ride with it disconnected as well just to see how it runs, since that has served Jim so well. Thanks again for all the great input. Ken, Call me after (I can ride after 11) if you want someone to ride along with you while you're testing the bike. Link to comment
dirtrider Posted March 23, 2011 Share Posted March 23, 2011 ----- I may take a nice ride with it disconnected as well just to see how it runs, since that has served Jim so well. Thanks again for all the great input. Morning Ken They run pretty good with that 02 disconnected as that allows a slightly richer light/mid throttle mixture. It won’t help your top speed or help you at hi (above legal) hiway speeds. Short term riding with it disconnected won’t hurt a thing. If you decide to leave it (the 02) disconnected your cat will run slightly richer and hotter due to having to handle more burn off (the 02’s main duty is to protect the cat). It will also eventually ruin your new 02 sensor (remember just because it is disconnected doesn’t mean it quits working). The cat will not plug up but the continued richness it will eventually kill the cat’s ability to control emissions. (only a problem if desire to protect the atmosphere or need it working to pass future state/federal emission testing) I suggest that if leave the 02 disconnected for long term riding you remove your new 02 sensor and replace with a ( threaded plug) or just use the old 02 sensor as a plug. (no sense in ruining the new 02 sensor) Link to comment
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