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Strange chugging problem


photojournalyst

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photojournalyst

On my 95' R1100R (45K) sometimes when I start up and get it out on the street the engine will bog down, no matter how much or how little gas I give it. It'll slow painfully down (not good when merging with traffic) maybe twice within a mile of starting up, and then it won't do it again. Usually happens when the bike is cold, but sometimes when it's warm too. I also noticed, and this might be unrelated, but there is a chirping sound accompanied by a little surge every once and a while when I'm riding in first gear, never in any other gear. Might these be related? Any thoughts?

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Could be many things and I am sure others will offer ideas. Starting with the easy stuff first, assuming your servicing is up to date like plugs, TBS, air filter, fuel filter, I would really check the connections for the oil temp sensor between the sensor and the Motronic. If there is an open circuit in this connection the Motronic will default to 168f oil temp which will be way too lean when you start a cold engine, but will be not noticed when the engine is warmed up. Even if it is warmed up outside but the engine is cold you might experience a loss of power due to lean running (engine management thinks it is warmed up). This scenario will affect cold engine performance.

 

One other thing is make sure the rubber stub pipes between the cylinder heads and throttle body are in good shape and the bands are snugged at the throttle body. Air leakage here will also cause lean running. The stub pipes are likely cracked and dried out given the age of your bike. I replaced them on my 96 and the difference was remarkable

thumbsup.gif

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Check plug-leads and spark plugs as the conditions you describe put extra demand on the ignition system. It could be one of many things causing this but failing ignition leads or plugs are fairly easy to inspect and diagnose.

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photojournalyst

I checked the rubber thingies between the tb and the cylinder, and there are is some cracking, but I don't know if there are any holes. I'll get some ($38 apiece, cheap) and replace them, see what happens.

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Sounds like the O2 sensor could be going bad and not providing a "clean" signal until sufficiently warmed up by the exhaust gasses. Try unplugging the ccp to see if anything changes.

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photojournalyst
Sounds like the O2 sensor could be going bad and not providing a "clean" signal until sufficiently warmed up by the exhaust gasses. Try unplugging the ccp to see if anything changes.

 

what is the ccp? I know what the o2 sensor is, and where, but this is a new term for me.

 

thanks!

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what is the ccp? I know what the o2 sensor is, and where, but this is a new term for me.
Cat Code Plug. In the fuse box. Sets the fuel map. Do a search here for 'LPB" (Little Pink Bastard) and you'll find a bunch of info.
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photojournalyst

I'm going to sound ignorant again, but do I unplug the thing and then run my bike, or just re-seat it and then run?

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Short version - By changing to different CCPs, (or making your own) or none at all, then going through the throttle range reset procedure, you change the mapping.

 

Long answer - do a search of this board and you will find dozens of threads with the details. I don't have a link to one of them just now, maybe someone else will pop in with one if you can't find it with a seach.

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I'm going to sound ignorant again, but do I unplug the thing and then run my bike, or just re-seat it and then run?

Sorry, should have explained further.

 

Pull the plug and run the bike to see if the problem goes away.

 

Under normal operation, the O2 sensor provides continuous feed back on the amount of unburned gasses in the combustion stream allowing the Motronic to adjust and maintain the correct mixture for varying conditions (altitude, temperature, load, etc). Unplugging the Catalytic Code Plug (ccp) tells the Motronic to ignore inputs from the O2 sensor and set mixture based on the CO potentiometer, a simple variable resistor that allows the user to set optimum mixture for most common riding conditions. However, US spec bikes do not have a CO pot (because they come with an O2 sensor). Absent a CO pot, the Motronic defaults to a preset factory mixture setting.

 

If your O2 sensor is going bad, pulling the ccp will disable it and you should be able to tell if the symptoms go away. It may be a long shot that it’s the O2 sensor in the first place, but since the check is so easy to do (just pulling a plug in the relay box), there’s no reason not to. You can run the bike fine without the plug however, as the mixture is not being continuously optimized by the Motronic, mpg will decrease slightly. Also, since the default mixture is usually set somewhat rich, the plugs may slowly foul over time.

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photojournalyst

I'm going to pull it for my ride this weekend and see what happens since the throttle body pieces are a few days out (special order my butt).

 

Thanks!

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photojournalyst

Haven't had time to mess with the electronics. I just got the plastics bits today, so I'm going to do them both at the same time. I'll post results.

 

Thanks again for the help!

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photojournalyst

Holy hell batman.

 

Rubber thingies replaced. Didn't do crap, actually, bike might even run a bit worse. Not a happy camper.

 

Went to the bar. Came back (after lots of cola and oj, never drink and ride kids!) and decided on a whim to yank the pink plastic. Yanked it. Impression?

 

Butter smooth. A different bike completly. Wow. My god. This is why I ride a motorcycle!

 

Now the big question. I have stock muffler and cat, and I'm running a richer (I can smell it) mixture. I don't mind doing plugs, that's the easiest thing in the world. But surely there must be a software solution to this problem? Or I need a new o2 sensor, but at 45k, come on! My M3 had 110k on it before I did the o2, and all I got was 3 more miles per gallon, not problems with the engine running.

 

So what's the next step gang? New sensor? Run without the pink thingie and hope my cat doesn't get too hot? I can take an extra $.40 per fillup on fuel economy.

 

Thoughts?

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photojournalyst

Almost forgot. When I was doing the rubber thingies, I took out the ignition tubes from the jugs to get the wire out of the way. Noticed that the rubber boot at the top of the tube where it meets the wire is cracked, both sides. I'll probably replace these too. Maybe this is affecting things?

 

According to the dealer the TPS was checked before I bought the bike used (6k ago) and a TBS was done at the same time as well. Perhaps I bumped the throttle cables while working on the bike, or perhaps the ignition tubes need replacing.

 

Anybody got a twin max I can borrow?

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Personally, I would replace the sensor, there's a reason for all that fancy electronics and I prefer to keep my system as close to stock as possible. However, there are some who do just fine running without a ccp. Your call.

 

Looks like a new sensor for you bike runs about $150 from Chacago BMW. You might also want to do some research though. I seem to recall past discussions about the BMW sensor being just a standard car O2 sensor that can be had for around $40. Only modification required would be to wire it correctly to match the BMW plug.

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Lots of folks, me included have run their bike without the CCP for years with no problems. You can get a CO potentiometer from BMW which will enable you to change the air / fuel ratio if you are really concerned. Tha is how the European and Canadian bikes come, or so I've heard. Me? I'd just ride it.

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photojournalyst

If there are people that have put a few 20,000 miles or so without hassle, I just might have to pursue that route. I'm going to look into doing a TBS sync. Anybody live in Michigan and have a TwinMax I can borrow? grin.gif

 

Thanks for all the help guys!

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If there are people that have put a few 20,000 miles or so without hassle, I just might have to pursue that route. I'm going to look into doing a TBS sync. Anybody live in Michigan and have a TwinMax I can borrow? grin.gif

 

Thanks for all the help guys!

We've got over 50,000 miles on our LPB-less R1150RT's without problems.

 

With regards to needing a Twinmax, do a search for "+homemade +manometer +ATF, etc." and you should find lots of info on making your own manometer (more accurate and less problematic, IMHO) for just a few dollars from parts easily obtained at your local hardware store. thumbsup.gif

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I've done some research, and I just want to check in with some people, but is this- http://www.powerchutes.com/manometer.asp what we're talking about for the homemade variety? And it's as accurate as a twinmax?

 

That is the type of thing we are talking about. Rightspin - one of our members also has a description of how to make one here.

 

I used 2-stroke oil in mine. As for accuracy, carefully made they will be at least as accurate, if not more so, than a twinmax.

 

Andy thumbsup.gif

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photojournalyst

Cool. First thing first then, valve adjustment and ignition coils, and then for a tbs. This'll be interesting.

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If there are people that have put a few 20,000 miles or so without hassle, I just might have to pursue that route. I'm going to look into doing a TBS sync. Anybody live in Michigan and have a TwinMax I can borrow? grin.gif

 

Thanks for all the help guys!

 

 

I have a twinmax and I live in Michigan. So if you want to use it your welcome to it and I can give you hand if your somewhere close.

P.M me if interested..

Dave thumbsup.gif

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Where about in Michigan are you? Obviously a big state. If you are near Grand Rapids, PM me and I'd be happy to let you use my low tech manometer for a TBA or tools for a valve adjust.

I replaced the rubber piece between the throttle body and the head with very good results recently. The bike had behaved badly before, with unadjustable idle speed, but runs like a champ now.

I may just have to have another Tech Daze, come to think of it!

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photojournalyst

Whoa! Two, count them two people from West Michigan! I live in East Town in Grand Rapids. Got by bike from 60th and Division. I ride everyday working as a stringer for the local AP Bureau and the Grand Rapids Press (and a few others, but they're most of my work) so you might have seen me in the Rallye suit on a gray r1100r.

 

Not to rush things, but I would love to meet. Nevets- I've got to do a valve adjustment and replace my ignition coils before doing a TBS. If I could bribe you with beer or something since I've never done it before, and would feel better working under the auspices of somebody with a bit more experience.

 

PM me for an email, or else I'll simply have to send you me phone number.

 

Local Bimmer people!!!!!! grin.gif

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