Jump to content
IGNORED

rough running


ed may

Recommended Posts

Hi all, I have a minor issue that has been going on for some time, probably 5-10 thousand miles/ a  few seasons.  After about an hour of riding, the engine seems to run a little rougher, most noticeable around 3000 rpm in 4th, 5th and 6th. (left mirror vibrates a lot when it happens too)  I can also feel it on the center stand just bringing the rpms up to 2500-4000.  Seems to idle almost the same as when it's running smoother.   Not very obvious, but it's there.   I have scanned for codes in the past and again yesterday after a long ride and no codes.  It's an 06 RT with 28k on it.  I change oil regularly.  I adjusted valves at 25k, (didn't seem to make a difference).  4 new spark plugs and a throttle sync with ballance tool(was ok) and new air filter at 15k (2013).  So it doesn't seem to change if I shut off the bike for a few minutes.  If the bike cools off, it's better.  I scanned the engine data yesterday when I got home and was running rough.  Can someone please tell me what to look for as far as "additive trim" and "Multiplicative trim" values at different rpm's and idle?  The Lambda numbers I assume are supposed to fluctuate above and below 500mv?  (I'm an ex Chevy tech, so I know a lot about these numbers but not sure what's normal for this bike.)  Going through my records, I see I should probably do a throttle sync with the vacuum tool, but I don't feel confident that will fix it.  Should I be looking at any other 911 data?  Any recommendations?  Thanks!  PS, I have attached pictures of the scan data when it was running rough.  Some pictures are off idle rpms and some are at idle.  Pictures are in sets of 2 (one of the top of the data stream and one scrolled down to the bottom of the stream.   

20200516_180434.jpg

20200516_180455.jpg

20200516_180541.jpg

20200516_180558.jpg

Link to comment
1 hour ago, ed may said:

Hi all, I have a minor issue that has been going on for some time, probably 5-10 thousand miles/ a  few seasons.  After about an hour of riding, the engine seems to run a little rougher, most noticeable around 3000 rpm in 4th, 5th and 6th. (left mirror vibrates a lot when it happens too)  I can also feel it on the center stand just bringing the rpms up to 2500-4000.  Seems to idle almost the same as when it's running smoother.   Not very obvious, but it's there.   I have scanned for codes in the past and again yesterday after a long ride and no codes.  It's an 06 RT with 28k on it.  I change oil regularly.  I adjusted valves at 25k, (didn't seem to make a difference).  4 new spark plugs and a throttle sync with ballance tool(was ok) and new air filter at 15k (2013).  So it doesn't seem to change if I shut off the bike for a few minutes.  If the bike cools off, it's better.  I scanned the engine data yesterday when I got home and was running rough.  Can someone please tell me what to look for as far as "additive trim" and "Multiplicative trim" values at different rpm's and idle?  The Lambda numbers I assume are supposed to fluctuate above and below 500mv?  (I'm an ex Chevy tech, so I know a lot about these numbers but not sure what's normal for this bike.)  Going through my records, I see I should probably do a throttle sync with the vacuum tool, but I don't feel confident that will fix it.  Should I be looking at any other 911 data?  Any recommendations?  Thanks!  PS, I have attached pictures of the scan data when it was running rough.  Some pictures are off idle rpms and some are at idle.  Pictures are in sets of 2 (one of the top of the data stream and one scrolled down to the bottom of the stream.   

 

 

 

 

Morning Ed

 

With one or two static captures it is difficult to tell much, the trim values will vary with fuel alcohol content  & evap can purging so if they are not way out of line then the adaptives are bringing the fueling back in line.

 

The only things that stands out is the o2 heater being off on sensor 1  but that can come & go so as long as it "can" come on then all is probably OK there. Make sure the heater on sensor 1 can/does come on.

 

The other thing that looks off a little is the throttle position being at 0% with the RPM's at 1989 rpm's. I would think that to get 1989 rpms' you would have the throttle open a bit. (something to look into anyhow)

 

Has your battery been replaced or run flat without doing a new TPS relearn? Might not hurt to do a battery disconnect then do a new TPS relearn after battery re-connection.

 

That warm engine disturbance is not too far out of line on the BMW 1200 bikes, as that is happening at a high enough RPM that it probably isn't fueling related. The BMW 1200 hexhead boxer does have a known (inherent) disturbance  in the 3500-4200 rpm region. 

 

The BMW boxer is a basic flat twin boxer so the primary engine balance is inherently balanced. But the large pistons are not directly across from each other so under cylinder firing, or under road load, the engine has a rocking couple type disturbance (basic boxer buzz).   BMW added  a SINGLE balance shaft to counter the rocking couple but that is basically adding weighting off-set imbalance to an inherently balanced engine, so while it does reduce disturbance peaks it doesn't/can't eliminate the disturbance in the 3500-4200 rpm operational area.

 

With your disturbance seemingly getting more harsh (or getting worse) with a hot engine then you might look for things like the exhaust stretching out & binding on the muffler mount. Or even touching the center stand? (center stand up-stop area)

 

On my personal 1200RT hexhead I eliminated one bolt on the handlebar mount on each side then spaced the handlebars up with very thin stainless washers, then added a thicker "O" ring under the handlebars. This added a subtle hinge point & turned the handlebars into somewhat tuned buzz absorbers. I did this early on (before the camhead was released for sale). If you look at the camhead it looks like BMW had also found this same thing as the handlebar mounting is a 3 bolt affair.

 

I also made a set of heavier bar end weights  (these made a notable different in bar buzz reduction). You can find heavier end weights on-line, or I believe the heavier BMW 800 bar end weights will fit.

 

You might see if moving your feet around  the foot pegs (outboard more, or more/less weighting) changes the handlebar & mirror buzzing, if it does then you are probably  fighting with a basic chassis tuning issue set-off by the basic 1200 boxer buzz.

 

Not that  this is a major cause of the BMW 1200 engine disturbance but it can figure in-- look closely to see if your throttle body cams are starting to crack (many are starting to do that). You can look from underneath with a small mirror & strong light or from the top if you slide the plastic covers up the throttle cables. If the cracks get bad enough the plastic cam can crumble off the metal arm leaving the bike un-ridable. 

 

 

 

HoNRCYN.jpg

 

 

Link to comment

Thanks for the feedback dirtrider, as usual, I knew you would be all over this.  First off, I don't think it's part of any normal/inherent vibration, because it seems to change.  First hour or so of riding is great.  It's only after it's hot, and doesn't always seem to be as noticeable or do it 100% of the time.   So I don't think the handle bar spacing or weights are really an issue, or foot position.  I will check the #1 02 heater, exhaust mount for binding, exhaust contacting center stand.  I tried to look at the throttle cams, but not sure how you did that since it's on the inboard side.  I tried, but couldn't see.  I will try again when I roll it out of the garage.  As far as the addaptives go, is there a max positive or negative threshold that I should look for?  I will double check the throttle position at various throttle inputs, I see what you are talking about in that one picture, I think I took that picture while holding it at that RPM for several seconds so that throttle angle data should have been up to date.  I don't recall my battery ever going flat since I put the Odyssey battery in back at 18k, but I did replace the shocks about a year ago when I had that alternator exciter connector pop off causing a battery light, that you nailed.  There is a strong chance that I did disconnect the battery at some point for adding an accessory wire for cell phone charging or even for that shock job. 

***I will do a TPS relearn to play it safe, can you refresh my memory on how to do that???  I vaguely remember it's an output in the 911 engine list. 

Not sure what else to do.  If I am not crazy, it also seems like there is a very mild power loss when it runs like this, but so mild that it may be my perception/imagination.  

Link to comment

On a Hexhead, to reset and calibrate the TPS, you need to turn the ignition on (don't start the engine), let the bike fully "boot", fully twist the throttle 3 times and shut the bike off.

Should be good to go.

Link to comment
6 minutes ago, ed may said:

ok, how about the idle actuator calibration i see on the 911, should i try that too?

Afternoon Ed

 

You can do that but it won't gain you anything as they automatically re-home therefore re-calibrate at every key on. 

Link to comment
33 minutes ago, alexvtr said:

On a Hexhead, to reset and calibrate the TPS, you need to turn the ignition on (don't start the engine), let the bike fully "boot", fully twist the throttle 3 times and shut the bike off.

Should be good to go.

Afternoon  alexvtr

 

That won't do  anything  without a battery disconnect first as it won't go into calibration mode without the BMS-K keep-alive power down. 

 

Link to comment
14 minutes ago, ed may said:

ok, how about the idle actuator calibration i see on the 911, should i try that too?

Afternoon Ed

 

Yes, you can use that function instead of a battery disconnect.

Link to comment

Afternoon Ed 

 

 First off, I don't think it's part of any normal/inherent vibration, because it seems to change.  First hour or so of riding is great.  It's only after it's hot, and doesn't always seem to be as noticeable or do it 100% of the time.-- They can act like this as oil thins out, clearances open up, exhaust changes shape, etc. Shouldn't  be a big change but they can change slightly. 

 

   So I don't think the handle bar spacing or weights are really an issue, or foot position. -- Just try changing foot placement, foot weighting, & hands on or off of each side handlebar. Don't totally discount this until you eliminate it.

 

I will check the #1 02 heater, exhaust mount for binding, exhaust contacting center stand.-- Just check then eliminate this  as a possible cause.  

 

I tried to look at the throttle cams, but not sure how you did that since it's on the inboard side.  I tried, but couldn't see.  I will try again when I roll it out of the garage. -- Your will probably have to slide the plastic covers up the cables to see much.

 

As far as the addaptives go, is there a max positive or negative threshold that I should look for?-- There probably is but I don't know what the max would be.   As long as your o2 sensors keep toggling across the .450v center then you haven't reached max.

 

  I will double check the throttle position at various throttle inputs, I see what you are talking about in that one picture, I think I took that picture while holding it at that RPM for several seconds so that throttle angle data should have been up to date.--Just something to look at & understand what is happening.

 

  I don't recall my battery ever going flat since I put the Odyssey battery in back at 18k, but I did replace the shocks about a year ago when I had that alternator exciter connector pop off causing a battery light, that you nailed.  There is a strong chance that I did disconnect the battery at some point for adding an accessory wire for cell phone charging or even for that shock job. 

 

***I will do a TPS relearn to play it safe, can you refresh my memory on how to do that???  I vaguely remember it's an output in the 911 engine list.-- You can use your GS-911, or just do the battery disconnect (for about 5 minutes) , then re-connect, then key on,  then 2 full throttle sweeps (fully closed to fully open) using the twist grip. 

 

Not sure what else to do.  If I am not crazy, it also seems like there is a very mild power loss when it runs like this, but so mild that it may be my perception/imagination. -- You could have an upper stick coil starting to go out.  Pretty difficult to find until one gets bad enough to totally quit. Not much to measure as the secondary is isolated, but they usually start to fail by arcing internally & you can't easily measure that. Lower coils are pretty well phase-shifted out of meaningful use by higher RPM's so lowers are usually more of a curb idle problem.   

Link to comment

I think the 911 software/hardware is taxing my laptop a little, so the throttle reading wasn't updating.  (recently updated to Win 10 and doubled my RAM to 8GB, but still not a high end performing computer by any means.)  I looked at it again and it's fine.

With the 911 TPS learn, is it key on engine off?

If I do battery disconnect, is it 2 or 3 throttle twists?  Anything else affected by a battery disconnect?

Maybe I will replace the upper stick coils and consider it  a maintenance  thing due to miles and age, if they are not too expensive.  (was thinking about doing that with O2 sensors too, but I bet they are a bit pricey.  And don't want to start replacing all kinds of stuff that's not needed, (where do you stop!)

 

Link to comment
51 minutes ago, ed may said:

 

If I do battery disconnect, is it 2 or 3 throttle twists?  Anything else affected by a battery disconnect?

Maybe I will replace the upper stick coils and consider it  a maintenance  thing due to miles and age, if they are not too expensive.  (was thinking about doing that with O2 sensors too, but I bet they are a bit pricey.  And don't want to start replacing all kinds of stuff that's not needed, (where do you stop!)

 

Afternoon Ed 

 

1, 2, or 3 throttle fully opening/closing, it really doesn't matter. Book calls for only one but once it sets the learning you can do 50 more & it won't make any difference.

 

2 or 3 is usually a good choice just in case the first one didn't set. 2nd & 3rd is just insurance.

 

Doing the battery disconnect you could (not always do) lose the service reminder dates (simple re-set with GS-911). Probably lose your radio pre-sets also. You will also lose your learned BMS-K fueling adaptions (it will learn new correct ones).  

 

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...