Jump to content
grusgets

Throttle body idle screws. Poor idle and low speed jerkiness

Recommended Posts

grusgets

Hello!

I'm starting this new thread, with the hope to find a fix for my bike's poor idle and low speed jerkiness. I've made a few posts on another thread, but after dirtrider's recommendation, I'm making a new start here. Bike in question is a 2004, R1200GS, first generation of hexheads, with servos,, made for the European market (just in case it makes any difference), with 66.000kms on the clock. I think it was introduced in 2005 in the US. 

So, long story short, years ago, I moved my throttle body idle screws from their original position, with no obvious reason and as a result, idle and above idle speed became messy.

Here are some info about what is changed, repaired, modified or eliminated. The bike runs on a modified BMSK. Both ignition and fueling are remapped. Rev limiter is moved higher. Remapping took place from distance. I mailed my BMSK, and it was sent back modified. The bike was never dynoed. Headers and muffler are changed to aftermarket Remus. Headers are of larger diameter, with no connection tube. Muffler has its silencer installed. There is NO cat. Air filter is K&N. Air box and airbox snorkel are NOT modified. L/H side chain tensioner is replaced with the "better design" one. All sensors are installed and they report back. Engine runs on 10w-60 fully synthetic oil. Spark plugs are NGK iridiums, 15,000kilometers/4 years old. Valves were done on May, 2,000kms ago. Rocker arm end play is towards the lower end but not minimal. Both lambda sensors are installed and presumably work normally. Tuning guy assured me he did not eliminate them. Please note that remapping of the BMSK was performed after I moved the idle screws, and it did not make idling worse. The same guy said that his mod will not affect idling. He was not aware of my messy idle screws, and I never told him. I didn't want to complicate things.  

Bike is strong and I am satisfied with the modifications done. It is gentle with gas and oil consumption is minimal. Although strong however, engine is noisy, and I cant say that it runs great either. I can't even remember it being "smooth like butter" or "purring like a kitten" (borrowed expressions), perhaps because of me messing with the idle screws. I really don't know. Maybe an unbalanced condition, will promote strange noises. For example at very hot idle, I will hear both timing chains slapping on their guides. At steady throttle, and at "some" rpms, resonance noises will emerge from the valve train. Also, with engine at low rpm and operating temperature, and ONLY under load, it will rattle, from its center. It will do it more intensively when leaving from a traffic light. With a pillion it will be even worse. I'm just trying to give an overall picture of the engine here.   

Concerning the throttle bodies, the bike will always run better, but not perfect, after a cold start and during the first couple of minutes. It will change gears more quietly, it will idle sweeter, more powerfully, and it will not rattle. As it warms up, things will eventually get worse, noisier and clankier. Idle will "loosen", and throttle response will decrease. When leaving from a stop, I always have a feeling that something slightly holds me back (wheels turn freely of course). The worst is crawling with 1st or 2nd gear in the traffic with a pillion, at idle and above idle speed. Really terrible. I always slip the clutch and try to keep the speed and the rpms up. Sometimes it really sounds like a small diesel engine. And if I let it cool for, say 15-20 minutes, it is a totally different bike. Crazy!

 

In my other thread, Dirtrider had made me some questions which I think should be posted here as well for reference. The lines in brackets were added later. 


Are the o2 sensors still active & being used for fueling control?

Yes, they are still there and active, as far as I am told.

 

What is your current hot engine base idle RPM?

Can't be sure about this. Numbers play around 1100 and 1200.

[The numbers I am referring to, are displayed on the screen of my phone through the Motoscan app]

 

Have the base idle screws on the throttle bodies ever been moved?

Definitely yes. 

 

Is the blue TB idle screw indexing paint still intact? 

Blue paint is not visible. Not at all!

 

What are your cold start stepper counts?

I don't remember unfortunately. Around 120 I think. I can have that piece of information soon.

[I checked this today morning. From cold start at 28.5C, stepper counts were 144, on both sides. Soon after, with 39C, steps dropped to 139]  

 

Do the stepper counts ever go independent? Or are they always reading the exact same counts?

They always show the same reading. Always!

[They show the same count when they are connected. If I unplug one, its number will freeze, and the other stepper will continue to move around]

 

Are the throttle cables tight & not allowing the TB throttle shaft arms to firmly sit on the base idle screws?

No, both throttle cables are pretty loose.

 

I would really appreciate any help.

George

Share this post


Link to post
Share on other sites
dirtrider

Morning  grusgets

 

Thanks for starting a new thread, this way we can keep your thread going & separate.

 

I'm trying to understand your problem (what you posted above sure helps). But I'm still having a difficult time understanding the problem's root-cause issue.  We might have to poke around on it a little until we have a good  understanding. (I wish I could ride that bike as that would allow an instant understanding)

 

The hot engine stepper counts are a bit high but I don't think this has anything to do with your issue.

 

It doesn't sound like your base idle screws are set correctly but that is an idle thing only & probably isn't your  rough ride-off problem (or at least not the main contributor).

 

The other thing  making this more difficult is that you have a very early 1200 bike (I'm sure your early 1200 has no fueling computer updates so we don't know if your problem was addressed in later BMS-KP  firmware updates.

 

In just reading your above, the first thing that came to my mind is a lower stick coil (or coils) is not functioning correctly. The 1200 will run OK at speed with a lower stick coil not working but they idle badly & the launch from a stop is usually rough & jerky with sometimes internal engine rattles.

 

So lets start off with 3 things___

 

Can you see if the engine will run on JUST the lower spark plugs (It won't idle without adding throttle but should run on the lowers only (just unplug the upper coils then see if it will run on the lowers only)-- If it doesn't sound right or has problems running then (carefully) feel the front exhaust pipes to see if BOTH are hot & about the same temperature.

 

Second thing__ (with all 4 coils operating again) --  Your early 1200 should have (2) cylinder head temperature sensors (one on each cyl head). Can you see (in the GS-911 data if both are close  to same  temperature with engine running for a while & idling (post each side  temperature  here? ).

 

 

Have you done a proper TPS re-learn?  If so what is your hot idle TPS GS-911 reading?  If you haven't done a TPS re-learn then do that BEFORE taking the GS-911 TPS data. (if you don't know how to do a TPS re-learn then let me know & I will post the procedure)

 

 

 

    

 

 

Share this post


Link to post
Share on other sites
grusgets
2 hours ago, dirtrider said:

Can you see if the engine will run on JUST the lower spark plugs (It won't idle without adding throttle but should run on the lowers only (just unplug the upper coils then see if it will run on the lowers only)-- If it doesn't sound right or has problems running then (carefully) feel the front exhaust pipes to see if BOTH are hot & about the same temperature.

I tried that and the bike idles and revs exactly the same with the upper plugs either connected or disconnected. Disconnecting the upper plugs will make no difference. I did not ride it. I tested it on its center stand.

 

2 hours ago, dirtrider said:

Second thing__ (with all 4 coils operating again) --  Your early 1200 should have (2) cylinder head temperature sensors (one on each cyl head). Can you see (in the GS-911 data if both are close  to same  temperature with engine running for a while & idling (post each side  temperature  here? ).

Yes it does have two temp sensors indeed, one on each side. And luckily enough, today they are spot on. A week ago i can remember seeing them at least 6 degrees celsius apart. But i have moved the idle screws since then. 

 

20190906_165612.jpg.a7eaab5ee0362ea8438f4c317ba99986.jpg

20190906_165634.jpg.09c40b6028f596a6dcfb4160c5b73c2b.jpg

 

 

 

 

 

 

 

 

 

 

 

2 hours ago, dirtrider said:

Have you done a proper TPS re-learn?  If so what is your hot idle TPS GS-911 reading?  If you haven't done a TPS re-learn then do that BEFORE taking the GS-911 TPS data. (if you don't know how to do a TPS re-learn then let me know & I will post the procedure)

Yes I have. Every time I move the L/H idle screw or charge my battery or store for winter, I do a tps re-learn. I don't understand what GS-911 TPS data is. I don't have a GS-911. I use the android app called Motoscan.

Share this post


Link to post
Share on other sites
dirtrider

Morning  grusgets

 

As a rule I like to see the cylinder head temp readings be slightly different. They almost never match exactly so when they read the EXACT same it usually points to the BMS-KP using one side reading for both sides (not a big deal as on later 1200 bikes BMW eliminated one cyl heed temp sensor & used just one side to feed temp to both sides). 

Or, it could be telling us that one side is not working correctly so the BMS-KP  substituted the working side input for the non working side. (keep an eye on the cylinder had temps to see if they vary slightly side to side) 

 

I haven't ever used Motoscan myself but have worked with a couple of  riders that were using one.  It complicated things as some of the data they got from the Motoscan didn't match what I expected to see from a GS-911 or dealer computer. 

 

I guess if that is what you have then we will have to work with it.

 

I'm still not exactly sure what we are dealing with here as you have the  idle screw/idle discrepancy with linked stepper counts (this is one issue to deal with)

 

But then you also have the launch problem  & engine rattle issue.  

 

I'm not sure that your idle problem is linked to your launch/rattle problem.  

 

Let me think on this for a bit, I will post more later.

 

 

 

 

Share this post


Link to post
Share on other sites
dirtrider

Afternoon grusgets

 

More thoughts____

 

What does your Motoscan show for TPS position data? Does it have a TPS setting option?  

 

Messing with the L/H base idle screw can change the TPS  base position vs idle/above idle  lift off.

Share this post


Link to post
Share on other sites
grusgets

It only has one option, under analog outputs, which is called "relative throttle angle".

It will go from 0,00% to 100% with engine either on or off. On idle it is showing 0,00%.

 

1 hour ago, dirtrider said:

Messing with the L/H base idle screw can change the TPS  base position vs idle/above idle  lift off.

I know, but I have already messed with this screw. It can't get any worse, right?

Share this post


Link to post
Share on other sites
Ponch

What's the total mileage on the bike? Just curious. 

Share this post


Link to post
Share on other sites
grusgets
4 hours ago, Ponch said:

What's the total mileage on the bike? Just curious. 

66,000kms

Share this post


Link to post
Share on other sites
dirtrider
18 hours ago, grusgets said:

It only has one option, under analog outputs, which is called "relative throttle angle".

It will go from 0,00% to 100% with engine either on or off. On idle it is showing 0,00%.

 

I know, but I have already messed with this screw. It can't get any worse, right?

 

Morning grusgets

 

Again, I don't know how the Motoscan reads the TPS info but the full sweep of 0-100% sounds like you are getting full TPS authority. (I guess we have to assume that your TPS is OK unless we see something later that points back to it).

 

We still have to verify that the lower spark plugs are operating correctly (very important for proper idle, just above idle, & launch). Once up to mid engine RPM & above then the lower spark plugs are pretty well out of the picture & make little to no difference. 

Share this post


Link to post
Share on other sites
grusgets

Should I try again to set my idle screws to a new position and see what happens? I may have a way to roughly bench calibrate them with some vacuum and a homemade manometer. If I get them closer to the "correct" position, and see that rattle or jerkiness of the motor decreases, it will be a good sign. If not, I can try setting them to another position, and then again to another, and so on.  

Share this post


Link to post
Share on other sites
Ponch
6 hours ago, grusgets said:

Should I try again to set my idle screws to a new position and see what happens? I may have a way to roughly bench calibrate them with some vacuum and a homemade manometer. If I get them closer to the "correct" position, and see that rattle or jerkiness of the motor decreases, it will be a good sign. If not, I can try setting them to another position, and then again to another, and so on.  

In the original TB pulley replacement post, dirtrider has procedure for setting the screws. 

Share this post


Link to post
Share on other sites
dirtrider
16 hours ago, grusgets said:

Should I try again to set my idle screws to a new position and see what happens? I may have a way to roughly bench calibrate them with some vacuum and a homemade manometer. If I get them closer to the "correct" position, and see that rattle or jerkiness of the motor decreases, it will be a good sign. If not, I can try setting them to another position, and then again to another, and so on.  

 

Morning  grusgets

 

Eventually you will probably want to do that BUT if you keep trying to get ahead of things & jump around then I am wasting my time trying to help you.

 

WILL THAT ENGINE RUN ON JUST THE LOWER SPARK PLUGS??????????????????????????????????-- this is the next thing to verify.

 

Before you move anything on the base idle screws we need the hot engine curb idle stepper counts as well as the hot engine side to side  manometer column height differences, plus we need to know if the engine is operating in closed loop at the time that you are obtaining the above.  (the above 3 things need to be obtained at the same time & same engine run cycle)

 

If you start jumping around trying things/turning things  then we loose the base line & have no idea on where we are at or what is happening (didn't randomly turning/adjusting  things  get you into this mess?)

 

 

 

 

Share this post


Link to post
Share on other sites
grusgets

Hello dirtrider.

Thank you for your answer.

 

The engine will idle and run with just the lower spark plugs connected, as I have written a few posts earlier.

 

Will try later to upload pictures of the manometer height difference and the stepper count on hot idle. As for the "engine closed loop", are you referring to the O2 sensor closed loop or something else? 

 

Thank you

 

 

 

 

Share this post


Link to post
Share on other sites
dirtrider
1 hour ago, grusgets said:

Hello dirtrider.

Thank you for your answer.

 

The engine will idle and run with just the lower spark plugs connected, as I have written a few posts earlier.

 

Will try later to upload pictures of the manometer height difference and the stepper count on hot idle. As for the "engine closed loop", are you referring to the O2 sensor closed loop or something else? 

 

Thank you

 

 

 

 

 

Morning  grusgets

 

OK, I somehow missed your response above about running OK on the lower plugs, (that eliminates that)

 

Yes, on the o2 sensors &  closed loop.

 

If your Motoscan has a "lambda control factor" column see what that is saying (like a 1 or a   larger number).

 

Best way to see what is happening (closed loop wise)  is to watch the lambda (o2 sensor) output voltages as the engine is running.  If you see the numbers toggling  above & below .500 volts (like 340.1 / 620.3 / 200.8 / 766.4 / 470.7 / 689.6 etc  then that means the lambda sensors are controlling the fueling on that cylinder.

 

 

Share this post


Link to post
Share on other sites
grusgets

Hello dirtrider.

 

I'm back again with some fresh feedback. 

Fortunatelly, Motoscan will show what lambdas are doing. It has a line called "oxygen-sensor control". At hot idle it says "active". if I accelerate the engine it will switch to "not active", the same during deceleration. When rpm stabilize to idle, it will say again "active". I didn't have the opportunity to check it at cold idle. When i started taking my measurements, engine was already at operating temperature. I had to ride to go to my garage.

 

Lambda voltage fluctuated between 0.2v and 0.8v, however one lambda was faster enough than the other. I used torque automotive app to obtain the lambda voltages, because Motoscan was not very straight forward with these numbers. I toggled between the apps in the same engine cycle.

 

Vacuum height difference began at 4", and increased to 5.5" as engine temp kept rising. I didn't measure the internal diameter of the clear hose, but it will fit firmly on the TB nipples if this helps.

20190908_183529.thumb.jpg.ba4f69792473e7e89d350472ae10c108.jpg

 

20190908_183736.thumb.jpg.9130fc59258dcce1f2c6572c96cf7cf3.jpg

 

I took three screenshots with 2 minutes interval, of the stepper count and the cylinder head temp. You can use temperature as the sequence reference.

 

20190909_055216.thumb.jpg.f0f475627f2f854c6654086b2ab64caa.jpg

 

 

20190909_055251.thumb.jpg.d49d6541e7d0a0dfd3fb3fad2f0e5eec.jpg

 

 

20190909_055312.thumb.jpg.e4598c24389a957cca3ecfd6edec5254.jpg

 

 

However, during the time i spent to my garage, there are three other things that i noticed.

 

1) Knock sensor reference voltages had a constant discrepancy of around one voltage during the whole time I had Motoscan connected. 

20190909_055341.thumb.jpg.f02e8a14078b8833e55abf80c9ee4b14.jpg

 

2) When i hot-started the engine for a second time, oxygen sensor control was constantly inactive for a minute or so. Then it toggled to active, without me doing anything.

 

3) The last time that I turned the ignition on, without starting the engine, just before leaving for home (with the Motoscan still connected, and my phone in sight, inside a clear pocket of my tank bag), I'd like to draw your attention here, I observed that the stepper count was 194 at both sides, instead of 204, as it always is. I cycled the ignition off and on, and again the steppers showed a count of 194. I had my both hands on the handlebars at the moment so I spontaneously turned the throttle, and to my surprise i heard the steppers moving. With zero throttle they showed 194, and with tiny throttle opening they jumped to 204. The bike acted like this the whole day, yesterday. 

Watch the video. What you can't see is my hand opening the throttle. You will hear them, move to 204 and then back to 194, two times. At the same time I open and close the throttle two times.

Honestly, I have never noticed this thing on my bike for years! 

 

 

Thank you!

George

 

Share this post


Link to post
Share on other sites
dirtrider
1 hour ago, grusgets said:

Hello dirtrider.

 

I'm back again with some fresh feedback. 

Fortunatelly, Motoscan will show what lambdas are doing. It has a line called "oxygen-sensor control". At hot idle it says "active". if I accelerate the engine it will switch to "not active", the same during deceleration. When rpm stabilize to idle, it will say again "active". I didn't have the opportunity to check it at cold idle. When i started taking my measurements, engine was already at operating temperature. I had to ride to go to my garage.

 

Lambda voltage fluctuated between 0.2v and 0.8v, however one lambda was faster enough than the other. I used torque automotive app to obtain the lambda voltages, because Motoscan was not very straight forward with these numbers. I toggled between the apps in the same engine cycle.

 

Vacuum height difference began at 4", and increased to 5.5" as engine temp kept rising. I didn't measure the internal diameter of the clear hose, but it will fit firmly on the TB nipples if this helps.

20190908_183529.thumb.jpg.ba4f69792473e7e89d350472ae10c108.jpg

 

20190908_183736.thumb.jpg.9130fc59258dcce1f2c6572c96cf7cf3.jpg

 

I took three screenshots with 2 minutes interval, of the stepper count and the cylinder head temp. You can use temperature as the sequence reference.

 

20190909_055216.thumb.jpg.f0f475627f2f854c6654086b2ab64caa.jpg

 

 

20190909_055251.thumb.jpg.d49d6541e7d0a0dfd3fb3fad2f0e5eec.jpg

 

 

20190909_055312.thumb.jpg.e4598c24389a957cca3ecfd6edec5254.jpg

 

 

However, during the time i spent to my garage, there are three other things that i noticed.

 

1) Knock sensor reference voltages had a constant discrepancy of around one voltage during the whole time I had Motoscan connected. 

20190909_055341.thumb.jpg.f02e8a14078b8833e55abf80c9ee4b14.jpg

 

2) When i hot-started the engine for a second time, oxygen sensor control was constantly inactive for a minute or so. Then it toggled to active, without me doing anything.

 

3) The last time that I turned the ignition on, without starting the engine, just before leaving for home (with the Motoscan still connected, and my phone in sight, inside a clear pocket of my tank bag), I'd like to draw your attention here, I observed that the stepper count was 194 at both sides, instead of 204, as it always is. I cycled the ignition off and on, and again the steppers showed a count of 194. I had my both hands on the handlebars at the moment so I spontaneously turned the throttle, and to my surprise i heard the steppers moving. With zero throttle they showed 194, and with tiny throttle opening they jumped to 204. The bike acted like this the whole day, yesterday. 

Watch the video. What you can't see is my hand opening the throttle. You will hear them, move to 204 and then back to 194, two times. At the same time I open and close the throttle two times.

Honestly, I'd never noticed this thing on my bike for years! 

 

 

 

Thank you!

George

 

 

 

Afternoon George

 

This is both good news & bad news.

 

The good news is that your liquid column height is well within reason (under 200mm side to side variance is good & under 250mm  is OK.

 

You do seem to be going into closed  loop with o2 sensors toggling across the center value (so fueling control is working).

 

Stepper counts are just a bit high but should work where they are at (they are not running  out of travel).

 

The steppers following the throttle opening/closing  is normal as that is an anti-stall feature for a sudden dropped throttle.

 

Your steppers are not going independent & your cylinder head temperatures are the same (this is something we need to figure out).

 

On the steppers not going independent, once you reach closed loop,  is a puzzler (you do have a very early 1200 bike), way earlier than I have ever worked with so possibly at that BMS-KP firmware iteration that wasn't available yet.  (my guess is that it had independent stepper control but I have no way to verify that other than a guess).

 

On the  cylinder head temp readings being identical?-- THIS is also a puzzler-- Some possibilities on this. With you having a re-programmed BMS-KP it's possible it was somehow updated to use the later firmware. Later firmware ONLY used one side  cylinder head temp reading. If only one cyl head temp sensor is being used for calculations then you WILL (always) have matching cylinder head temperatures. (this is something to look into)

 

This also m-i-g-h-t factor into the steppers not going independent as on the early 1200 bikes I have suspected that the cylinder head temperatures were use as part of the stepper  control feed-back. (never proved just guessed at).

 

I also don't know what you have going on with the knock sensors__ It's possible that you have a sensor or sensor(s) issue, or very possible the pizo knock sensors are picking up (& reacting to) all that engine noise that you are hearing.  

 

I wouldn't adjust anything on the base idle screws just yet as the problem  really isn't pointing in that direction.

 

You might try disconnecting one cylinder temperature sensor,  then reconnecting & disconnecting the other cylinder temperature sensor to see if you can define IF the fueling computer is using JUST one for both sides or using both (as the early 1200 bikes should be). 

 

You might also try running & riding the bike with both knock sensors disconnected (you need to try & understand WHY they are doing what they are doing).

 

This is getting more & more difficult to understand over the internet--  Having a very very early European 1200 sample bike, having a modified BMS-KP, not using a GS-911, doing it over the internet without hearing or riding the bike  is making diagnosing a difficult problem extremely difficult.

 

We'll keep poking along as maybe we will uncover something____  

 

  

 

 

 

 

Share this post


Link to post
Share on other sites
grusgets

Hello dirtrider.

 

I will try to talk to the tuning guy and see if tells me anything that could help.

Question: Is it ok if I temporarilly install on the bike another unmodified BMSK for testing purposes? Any possible problems with immobilizer, ZFE or KOMBI?

 

Thanks

Share this post


Link to post
Share on other sites
dirtrider
3 hours ago, grusgets said:

Hello dirtrider.

 

I will try to talk to the tuning guy and see if tells me anything that could help.

Question: Is it ok if I temporarilly install on the bike another unmodified BMSK for testing purposes? Any possible problems with immobilizer, ZFE or KOMBI?

 

Thanks

 

Morning  grusgets

 

On installing a different BMS-KP unit, I just don't know. The BMS-KP is a coded part (coded to the motorcycle vin). I'm really not sure if it work a little, work at all, or even allow basic functions. It might not even recognize your present coded key as they usually need EWS programming . As a rule when a new BMS-KP is installed it needs a CIP  (coding, individualisation and programming) done.

 

I guess you can try to install the new (used) one, then try to address any problems that show up (might not even recognize the key or start though).

 

 

Share this post


Link to post
Share on other sites
Ponch
16 hours ago, dirtrider said:

 

Morning  grusgets

 

On installing a different BMS-KP unit, I just don't know. The BMS-KP is a coded part (coded to the motorcycle vin). I'm really not sure if it work a little, work at all, or even allow basic functions. It might not even recognize your present coded key as they usually need EWS programming . As a rule when a new BMS-KP is installed it needs a CIP  (coding, individualisation and programming) done.

 

I guess you can try to install the new (used) one, then try to address any problems that show up (might not even recognize the key or start though).

 

 

Is that only done with a dealer level tool or can the GS911 do it?

Share this post


Link to post
Share on other sites
dirtrider
7 hours ago, Ponch said:

Is that only done with a dealer level tool or can the GS911 do it?

 

Morning Ponch

 

As far as I know only a dealer computer. (this is on a U.S. bike). I'm not even sure if a dealer with the proper disk could program in a used (already coded BMS-KP).  

 

The OP here has a non U.S. bike that is a year earlier than I have any documentation on so I don't even show a BMS-KP available.

 

 

 

 

  • Like 1

Share this post


Link to post
Share on other sites

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...