intermittent miss, 02 R1150RT...suggestions for possible cause

This is my first post as well as my 1st BMW. Bike has 49K miles. It has this momentary miss at highway speed. I have ridden as long as 45 minutes and as little as 15 minutes before it dose it. Has never stopped, the miss is so quick that I can't get a look at the tack or lights to see if anything changed.

The bike starts fine, runs well and never seems to have a problem if always working the throttle.

I have replaced the fuel filter, checked the valves, replaced the spark plugs, & hall sensor. Balanced the TB and adj. idle. Spark plug wires seem to be ok, tested coil (as much as one can...) I also took apart the side stand switch to see if it was bad, but all test don't seem to suggest it is the problem. Clean air filter.

Checked for shorted wires at the ignition switch, and generally all over the bike.

The previous owner installed a Battley R259 fuel control and O2 sensor. I have it turned to "off" but not disconnected.

Any feed back would be great as I am about worn out w this situation.

Thanks for reading.

Is this an early R1150RT with the single central coil under the gas tank?

If so, an intermittent failing coil would be my feedback. You'll find used coils around for about $45-$65, or a new coil from BMW. The miss will get worse, put you to the side of the road briefly then restart; eventually it will give you a no-spark, tow it home.

Morning Gravelpounder

At hiway speeds that sort of takes it out of (above) the range that TB balance will effect the runability.

If it doesn't act up as long as you keep moving the throttle that usually takes the ignition coil & spark plug wires out of the equation.

As a rule if you get good runability at moving throttle but not at steady throttle then you are looking for a closed loop issue (like o2 sensor or possibly that added fuel controller)

The early R259 fuel control units were noted for moisture intrusion then sporadic engine operation. (even turning it off won't always remove the issue)-- So try completely removing it from the bike.

The other thing that comes to mind is that someone has routed the o2 sensor pig tail too close or along the R/H spark plug wire (that can drive the Motronic fueling computer crazy at times due to RFI influence)

Another thing to check is that the o2 sensor wire hasn't now, or at one time, dropped down & become burnt on the exhaust system (this can screw the steady throttle fueling up)

The 02 BMW 1150 engine ran quite lean for the single spark heads so were marginal for closed loop operation even when all is well with them.

If you can find it you might try a tank of non alachaol gasoline. (at least see if it makes a difference)

Another thing to look at is the rear of the catalytic converter. A crack can form back there & allow air to be sucked into the exhaust system. While that won't really effect engine operation it can make the exhaust sound like the engine is misfiring at speed (missing sound will go right away if you open the throttle)

You might also try riding it with the o2 sensor disconnected as you might have a defective or poisoned o2 sensor. Or just install a new correct o2 sensor.

I have owned a couple of early (single spark) 1150RT's & they all ran very lean for the single spark combustion process.

Back then we pretty well used the Techlusion to help the light-throttle steady-road-load operation but now there are much better devices available. (like the AF-XIED)

Added: have you done a TPS re-learn? That teaches the Motronic the throttle min & max position. This should be done if the battery was disconnected or run down. (see TPS re-learn below ***)

If that bike sat unused for a time before you bought it you might also remove the fuel injectors & send them out for cleaning & testing (modern gasoline gums up injectors pretty quickly if the engine sits unused for a while) or at least try adding some extra Techron to your fuel tank).

Another thing to look at (test for) is fuel flow out of the fuel return line-- The older BMW 1100/1150 had high pressure hoses inside the fuel tank that were prone to pin holes & splits. A major hole or crack/split will stop the engine dead in it's tracks but a small hole or crack can lower the fuel pressure just enough to effect high speed engine operation under road load.

*** To Do a TPS re-learn--

(with choke OFF)

*Remove fuse #5 for about 3 minutes, then re-install the fuse.

Then

*Switch on the ignition. (do not start engine)

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 TPS where closed & open throttle is.

D.R.

Thanks for the reply, I have new O2 sensor to install, after disconnecting the current one. I didn't experience the miss...(although a short test ride)that led me to suspect that might be the problem. Sure changed way characteristics of the bike...I didn't like it w/o the O2 sensor.

Will check the TBS too

Thanks again

Dan

Morning Dan

One thing that I forgot to mention in my above post is make sure that your bike still has the original CCP in the fuse box --some riders removed it thinking it would help runability)

--(it did on the 1100 but not on the 1150, makes the 1150 run worse)

Most 1150 single spark US bikes came with the pink CCP installed.

Added: once you disconnect the o2 sensor (for a test) you should also remove fuse #5 for a while (at least 1/2 hour) then do a new TPS re-learn. That will remove the adaptive values that the fueling computer learned (& stored) from the old o2 sensor's input.

D.R.

Thanks for the help,

I don't have the pink CCP plug, must has been pulled out by the previous owner. Can I make a jumper or better to go to beemer boneyard for a replacement?

This bike was originally sold new in California, would that make any difference in how the bike was set up for emissions?

BTW the charcoal canister has been removed.

Dan

D.R.

 

Thanks for the help,

 

I don't have the pink CCP plug, must has been pulled out by the previous owner. Can I make a jumper or better to go to beemer boneyard for a replacement?

 

This bike was originally sold new in California, would that make any difference in how the bike was set up for emissions?

 

BTW the charcoal canister has been removed.

 

Morning Dan

There really isn't/wasn't a California BMW 1150RT as ALL BMW 1150RT's imported into the US were Ca. compliant.

Your 1150 probably came with a pink CCP (GS was different)

Yes, you can make a simple jumper-- for the pink CCP you need to jumper A to C to D (see attached picture)

D.R.

Thanks for the help! I report back after jumper & O2 switch.

Really appreciate the help.

I keep trying to remind myself of the passage in the book "Zen and the Art of Motorcycle Maintenance" where the author talked about seeing repair as a chance to learn. How you should turn frustration into an opportunity to learn something about what you don't understand. Right now it'd be nice just to take a mindless cruse...

Dan

Evening Dan

Just remember that after any CCP change, or CCP jumper change, or new o2 sensor install you should remove fuse #5 for about 5 minutes to allow the Motronic to clear it's learned fuel adaptives (learned fueling off-sets).

Then do a new TPS re-learn procedure after fuse #5 re-install.

D.R.

I made the jumper and did a test ride, still got that momentary hesitation 3 time in a 30 minute ride. I read that w/o the CCP the bike would run rich and carbon build up could occur in the head and on the O2 sensor...so,I'll put in the new O2 sensor tomorrow, test ride and see...

Again thanks for helping...

Dan

D.R.

 

I made the jumper and did a test ride, still got that momentary hesitation 3 time in a 30 minute ride. I read that w/o the CCP the bike would run rich and carbon build up could occur in the head and on the O2 sensor...so,I'll put in the new O2 sensor tomorrow, test ride and see...

 

Evening Dan

What you read was probably for the BMW 1100 as removing the CCP on the 1100 (Ma 2.2 system) removes o2 sensor control, on your 1150 removing the CCP does not disable closed loop so it shouldn't run rich & in fact removing the CCP on the 1150 (Ma 2.4 system) shouldn't cause any rich running, just poor running in some RPM zones.

Exactly.

I replaced the O2 Sensor and removed the R259 fuel controller...pulled fuse #5 waited 30 minutes, but fuse back in, turned on ignition, rolled throttle to full open 3 times, turned of ignition, turn back on, bike stumbled to start, had to keep throttle to 2000rpm, very rough running, will not idle.

Do I need to re-balance the TB and idle?

Right now... wishing I had kept my 750 Magna

Evening Gravelpounder

Are both exhaust pipes about the same temp after running for 30 seconds?

You might have the R/H throttle cable out of the adjustment furrel on the R/H TB (sitting on top of the furrel instead of down in it where it belongs) --Verify that both side throttle plates lift off of the idle stop screws at EXACTLY the same time.

A throttle cable out of place is a very common happening after working on R/H side of bike.

If this isn't the problem then try disconnecting your new o2 sensor. Might be something wrong with the sensor, or it is wired incorrectly (was it a plug in sensor or a universal that needed splicing in?)

Did you plug the R/H fuel injector back in after removing the Techlusion device?

D.R

I'll see if I can get an idea of the temp of the pipes.

Thanks again, it really helps to have another head in this game.

Dan

Evening Dan

Don't stress too much over getting it all repaired on the first try.

BMW motorcycles are a different animal than most Japanese bikes so there is a learning curve that usually must be met before little got-ya's quit pestering you.

Once you get the basics of BMW (strange) engineering they are really not difficult to work on. (not difficult, just different)

D.R.

Roger 04 rt

I just finished a 40 minute ride, the 1st sense I purchased this RT and did not experience any intermittent miss!

D.R. you called it...the Rt side throttle cable was out of its seated position, bike started fine after I corrected that and ran very nice.

I held the RPM at about 3000 for some time but I didn't get any surging either...so it was either the O2 sensor or the Fuel controller... anyway I'm crossing my fingers in that the problem is FIXED!!

Thanks for much for your help and guidance.

Dan