idle cutoff R1100S

[bacos]

I am really sorry if this has been discussed, but I don't even know the right term to look for, though I recall various discussions about it.

 

My '99 R1100S has a pretty significant throttle-on/throttle-off cutoff - if I try to feather the throttle down to idle, at some point the motronic seems to just cut off the fuel and I get this really wonderful engine braking that quite often I just really, really don't want happening. Like, say, hard braking before an Alpine hairpin. Having your rear wheel break loose just before you need to start leaning over is NOT fun.

 

It does seem like it's worse than it was, but I also haven't ridden it in 3 years. (It went to the dealer for brake flush/etc and they ok'ed it but what does that really mean. And I will note that when I first got it out, it was chewing fuel like a mofo, down to about 30MPG, I ran a whole bunch of injector cleaner through it and it's better now but it still feels a little off somehow.)

 

As far as I know, it's a stock bike, US spec even though it's in Europe. 89k on the clock. Been like this as long as I've known the bike, which is about 9 years and 33k.

 

Ok, I know some of it is just "yeah that's what it does". And yeah of course if you close the butterflies that's gonna have an effect. However I've been unable to find any sort of useful middle ground of "crack it a little but not have the injectors come online enough enough that it starts trying to make power" either. And the hard part about it is that it's sudden - if the engine braking came on progressively, you could let off the brake as you let off the throttle and transition, but...

 

Has anyone ever come up with any mods to improve the situation?

 

[dirtrider]

53 minutes ago, bacos said:

I am really sorry if this has been discussed, but I don't even know the right term to look for, though I recall various discussions about it.

 

My '99 R1100S has a pretty significant throttle-on/throttle-off cutoff - if I try to feather the throttle down to idle, at some point the motronic seems to just cut off the fuel and I get this really wonderful engine braking that quite often I just really, really don't want happening. Like, say, hard braking before an Alpine hairpin. Having your rear wheel break loose just before you need to start leaning over is NOT fun.

 

It does seem like it's worse than it was, but I also haven't ridden it in 3 years. (It went to the dealer for brake flush/etc and they ok'ed it but what does that really mean. And I will note that when I first got it out, it was chewing fuel like a mofo, down to about 30MPG, I ran a whole bunch of injector cleaner through it and it's better now but it still feels a little off somehow.)

 

As far as I know, it's a stock bike, US spec even though it's in Europe. 89k on the clock. Been like this as long as I've known the bike, which is about 9 years and 33k.

 

Ok, I know some of it is just "yeah that's what it does". And yeah of course if you close the butterflies that's gonna have an effect. However I've been unable to find any sort of useful middle ground of "crack it a little but not have the injectors come online enough enough that it starts trying to make power" either. And the hard part about it is that it's sudden - if the engine braking came on progressively, you could let off the brake as you let off the throttle and transition, but...

 

Has anyone ever come up with any mods to improve the situation?

 

Afternoon bacos

 

The BMW 1100/1150 boxers do have a closed-throttle fuel cut off (shut-off) that happens right around >.4 TPS volts and above 1800 RPM's. Once below about 1800 (+/-)  the fueling comes back on but it can be kind of abrupt at times, you can definitely feel it while riding.  

 

We can get into this in more detail after you ride the motorcycle again.  This time try riding it with the choke on (don't worry it really isn't a choke as ALL the choke does on your motorcycle is raise the idle RPM's, no actual enrichening or added fuel).  If your choke (fast idle is set on the low side it might not have much effect though as it seems to be around 2° (or close) of throttle that the fuel cut-off happens).

See if riding with the choke on eliminates your dropped throttle abrupt decel issue then we can talk about the next move or moves from there. 

 

Also try dropping the throttle as normal then adding a little throttle  back to see it that makes a difference. 

 

You say you haven't ridden it in 3 years, have you done a TPS re-learn since starting to ride it again (especially if it had a dead or disconnected battery?) 

 

 I guess the easy place to start is to do a TPS re-learn--

 

(with choke OFF)

*Remove fuse #5 for about 5 minutes, then re-install the fuse.

Then

*Switch on the ignition switch.

Then

*Without starting the engine, fully open/close the throttle twice so that 
the Fueling Computer can register the throttle-valve position.

then

*Switch off the ignition.

That's it, that re-teaches the Motronic where full closed & full open throttle is in relation to TPS input.

_______________________________________

Does you motorcycle still have the original CCP installed?  

 

Does it still have a factory exhaust system? 

[bacos]

Sorry DR. Got too much into riding and forgot to look at web.

 

Def factory exhaust and default whatever. No changes to bike.

 

The injectors were rather clogged from sitting too long... before I fed it some injector cleaner it ate gas like mad but it felt smoother. 

 

I forgot about the TPS re-learn. It def had a dead battery (obviously).

 

I'm back in the US now and not near the bike. I have one here in the US as well, but there is nowhere here one is going to ride aggressively enough that this ever matters. :( I'll try to see how this one behaves by comparison.

 

 

[BigtowH8]

On 7/2/2022 at 9:26 AM, dirtrider said:

Afternoon bacos

 

The BMW 1100/1150 boxers do have a closed-throttle fuel cut off (shut-off) that happens right around >.4 TPS volts and above 1800 RPM's. Once below about 1800 (+/-)  the fueling comes back on but it can be kind of abrupt at times, you can definitely feel it while riding.  

 

We can get into this in more detail after you ride the motorcycle again.  This time try riding it with the choke on (don't worry it really isn't a choke as ALL the choke does on your motorcycle is raise the idle RPM's, no actual enrichening or added fuel).  If your choke (fast idle is set on the low side it might not have much effect though as it seems to be around 2° (or close) of throttle that the fuel cut-off happens).

See if riding with the choke on eliminates your dropped throttle abrupt decel issue then we can talk about the next move or moves from there. 

 

Also try dropping the throttle as normal then adding a little throttle  back to see it that makes a difference. 

 

You say you haven't ridden it in 3 years, have you done a TPS re-learn since starting to ride it again (especially if it had a dead or disconnected battery?) 

 

 I guess the easy place to start is to do a TPS re-learn--

 

(with choke OFF)

*Remove fuse #5 for about 5 minutes, then re-install the fuse.

Then

*Switch on the ignition switch.

Then

*Without starting the engine, fully open/close the throttle twice so that 
the Fueling Computer can register the throttle-valve position.

then

*Switch off the ignition.

That's it, that re-teaches the Motronic where full closed & full open throttle is in relation to TPS input.

_______________________________________

Does you motorcycle still have the original CCP installed?  

 

Does it still have a factory exhaust system? 

@dirtrider

 

Thanks for you concise explanation and instructions.  

 

I needed the TPS re-learn after an extensive maintenance on my '03 1150RT (single spark): removed, inspect & cleaned fuel injectors (new O-rings), and throttle bodies (no rattle, so I elected not to rebuild, only clean); valve adj, r&r plugs, etc.  Tried to sync the TBs but she was running horrible - like I left a wrench in the cylinder and no adjustments worked to smooth.  I double checked my work - same result. Uffda! 

 

All sorts of  things went through my mind.  Vaguely remembered reading something about the TB re-learn a few years ago; WHEW, I found it.  Now I know what I'm doing Friday - TPS re-learn, sync. 

 

That leads me to ask what is the CCP?

 

 

 

 

 

 

[dirtrider]

9 hours ago, BigtowH8 said:

@dirtrider

 

Thanks for you concise explanation and instructions.  

 

I needed the TPS re-learn after an extensive maintenance on my '03 1150RT (single spark): removed, inspect & cleaned fuel injectors (new O-rings), and throttle bodies (no rattle, so I elected not to rebuild, only clean); valve adj, r&r plugs, etc.  Tried to sync the TBs but she was running horrible - like I left a wrench in the cylinder and no adjustments worked to smooth.  I double checked my work - same result. Uffda! 

 

All sorts of  things went through my mind.  Vaguely remembered reading something about the TB re-learn a few years ago; WHEW, I found it.  Now I know what I'm doing Friday - TPS re-learn, sync. 

 

That leads me to ask what is the CCP?

 

Morning BigtowH8

 

The CCP  is the (Cat Code Plug) that is the little "relay look alike"  that plugs into a socket in the fuse box. It's basic function is to force the Motronic (fueling computer)  to use a specific fueling/spark/emission map. 

 

 

[BigtowH8]

Great news (for me), yet no surprise (from you) using the proper sequence for the TPS re-learn resulted in the 1150 firing up with the enthusiasm of a thoroughbred on Derby day!  Oh, I wanted to ride right then, but there's a few things  of moderate importance yet to reassemble- headlight,  saddle, etc. Preformed TB sync with minimal adjustment. 

I love it when a plan comes together. 

 

So, this CCP thingy... how important is it for the 1150? 

The little I've read on it, it isn't clear if it pertains to my situation as an '03 1150RT (single spark) owner that does experience the surge between 3200 - 4000ish RPMs.

Perhaps you could share some more of your expertise; feel free to share link(s) to appropriate threads where you may have alreadyexplained. 

 

Kudos for the fuse box diagram.  You could get that printed on vinyl sticker and sell it.  (Apparently BMW didn't feel the need to label anything in the fuse box.  Details people,  details.)  Nicely done on the diagram dirtrider.

 

Thanks again for sharing your expertise.  You are awesome. 

[dirtrider]

7 hours ago, BigtowH8 said:

So, this CCP thingy... how important is it for the 1150? 

The little I've read on it, it isn't clear if it pertains to my situation as an '03 1150RT (single spark) owner that does experience the surge between 3200 - 4000ish RPMs.

Perhaps you could share some more of your expertise; feel free to share link(s) to appropriate threads where you may have already explained. 

 

Morning BigtowH8

 

On the BMW 1150RT (Ma 2.4) the CCP is important but just removing it  (like on the BMW 1100 Ma 2.2) doesn't do a lot of good at removing light throttle surging.  Removing the CCP on the 1150 Ma 2.4 doesn't deactivate the o2 sensor like on the BMW 1100 Ma 2.2 systems.

 

Removing the light throttle surging on the 1150 isn't easy, it can be effected or reduced but totally removing it usually takes some sort of aftermarket fuel controller that adds fuel in the lean-surge area. 

 

There is a reason that BMW went to the dual spark engine. 

 

The place to start is to get everything right, valve clearance, throttle body balance, clean fuel injectors, good working o2 sensor, TPS set correctly. 

Verify that it has a good CCP in it (usually the pink CCP in the 1150RT works best) 

 

Then ride the motorcycle for a while to get a good solid baseline. 

 

Once you have everything right & you have a baseline on the surging then you can start trying to remove it.

 

Try things like unplugging the o2 sensor, then remove fuse #5 for about 10 minutes, then do a new TPS re-learn. Now ride the motorcycle for a few days to see if that helps the light throttle surging.  

 

To really effect the light throttle surging on the 1150 Ma 2.4 single spark you might have to add something to help richen the light throttle fueling. Like the AF-XiED .

 

AF-XiED info______     https://www.beemerboneyard.com/bmwafo2sema.html