Engine seems to have a miss while riding

[2015 Blue RT]

My 2015 RT has developed what feels like a slight miss while riding at highway speeds, most noticeable under slight acceleration. It now has about 92k miles, I replaced plugs at 90k. Insulators were brown/tan. No idea if the coils are oem, but that is what it feels like to me. It looks like coils are around $180 each ☹️ so I wanted to ask about the symptoms first. I did a search in this forum for coil but didn't see anything relevant. Thanks.

[dirtrider]

13 minutes ago, 2015 Black RT said:

My 2015 RT has developed what feels like a slight miss while riding at highway speeds, most noticeable under slight acceleration. It now has about 92k miles, I replaced plugs at 90k. Insulators were brown/tan. No idea if the coils are oem, but that is what it feels like to me. It looks like coils are around $180 each ☹️ so I wanted to ask about the symptoms first. I did a search in this forum for coil but didn't see anything relevant. Thanks.

Morning 2015 Black RT

 

We first need to define what you feel in a bit more detail. 

 

Can you actually FEEL the miss in the in way the engine is pulling the bike along? (ie slight surge or slight buck as it misfires?) 

 

Or, is the miss all audio (your can hear it in the exhaust note but can't feel it in the engine pull or in your body?)  

 

[2015 Blue RT]

I can feel it, since I listen to music while riding I really can't hear the exhaust.

[Cap]

Perhaps DR can chime in on this question: do the wethead stick-coils fail any other way than on-off?  On my R1150RT, I had several failed coils, and they would always work perfectly until they failed completely. 

 

With an on-off failure, you can troubleshoot the problem by disconnecting the lead to the coil while the engine is running (roughly) and if there is no difference when you disconnect the coil, then the coil has failed.

 

Cap

[dirtrider]

1 hour ago, 2015 Black RT said:

I can feel it, since I listen to music while riding I really can't hear the exhaust.

Afternoon 2015 Black RT

 

OK, good info__ 

 

A coil starting to go out c-o-u-l-d be the cause, difficult to diagnose a coil until it totally fails unless you have a known-good coil to swap in. 

 

If the problem JUST started then you might try riding until the fuel tank is almost empty then re-fill at another gas station as a first test. A little water in the fuel, or  too much alcohol in the fuel, can at times, cause a light throttle engine miss. 

 

How I typically start looking for a road-load engine miss is to set up a GS-911 to trap engine data while riding, then pay attention to when in the riding sequence (run time/throttle position/engine RPM/ transmission gear) that the worst mis-fire was felt. 

 

Then when back to my shop match up the approximate (run time/throttle position/engine RPM/ transmission gear) to the engine data spread sheet to see if I can spot a reason in the trapped data for the engine misfire.  (probably won't outright  show a bad coil but could point to, or eliminate, other things) 

 

 

[2015 Blue RT]

OK thanks. I tried E10 (10% taxpayer subsidized alcohol) premium gas and found it robbed me of 2 MPG as compared to the ethanol-free I ran in the GSX1100. I've been using an additive called 104+ to help. I also need to see about the fuel and air filters presuming the fuel one is replaceable. This miss seemed similar to problems I've had in the past with coils, so that was my first thought.

 

I have an OBD2 adapter for the bike and an app for my phone. I'll have to learn how to set it up to capture data.

[dirtrider]

57 minutes ago, 2015 Black RT said:

OK thanks. I tried E10 (10% taxpayer subsidized alcohol) premium gas and found it robbed me of 2 MPG as compared to the ethanol-free I ran in the GSX1100. I've been using an additive called 104+ to help. I also need to see about the fuel and air filters presuming the fuel one is replaceable. This miss seemed similar to problems I've had in the past with coils, so that was my first thought.

 

I have an OBD2 adapter for the bike and an app for my phone. I'll have to learn how to set it up to capture data.

Evening 2015 Black RT

 

First thing I would try is to quit using that gasoline additive. Most of those so-called octane boosters use alcohol to boost octane rating.

 

I'm not sure  what it in that 104+ but it can't be good for your closed loop fueling control.  

[Hosstage]

If you pull your plugs, I will bet that they are a bit red from the 104+ additive. If so, I would change them, run good fuel through it, and see if it clears up or if the problem returns.

[2015 Blue RT]

OK, thanks. I'll look them over this weekend. I'll try a tank of the ethanol free w/o the additive and see how it runs. Everything I've read (to include user reviews) about the 104+ says it is compatible w/ converters and O2 sensors, so I hope that is not the cause.

[Hosstage]

I just know the few times I used it my plugs turned red. I'm not saying it affects the O2 sensor or the cat (none on my bike), I just know what I observed.

[dirtrider]

14 hours ago, 2015 Black RT said:

OK, thanks. I'll look them over this weekend. I'll try a tank of the ethanol free w/o the additive and see how it runs. Everything I've read (to include user reviews) about the 104+ says it is compatible w/ converters and O2 sensors, so I hope that is not the cause.

Morning  2015 Black RT

 

It might be compatible with your o2 sensors (as far as harm to them goes) but that doesn't mean it will fuel correctly when that stuff is burned in the combustion process.

 

Alcohol  is compatible with the o2 sensors but once it gets much above 12% the closed loop feedback starts to effect proper fueling control. 

 

I wouldn't bother pulling spark plugs, just run a few full tanks of non-additive-containing-fuel through that motorcycle to see if the misfiring decreases or goes away. 

 

BMW Wethead  motorcycles are designed & calibrated to use E-10 fuel (the fueling control automatically compensates) so BMW doesn't recommend using any fuel enhancing additives. 

 

About the only thing that I can (personally)  recommend to use (& even then use very sparingly) is to put a little Techron in once in a while as that keeps the fuel injectors clean so they have a nice crisp spray pattern.  (BMW offers their own version of a Techron fuel additive so it is obviously tested to not effect fueling control)

[Paul De]

2 hours ago, dirtrider said:

(BMW offers their own version of a Techron fuel additive so it is obviously tested to not effect fueling control)

Haha, I think the BMW formula is fill their labeled bottle with Chevron's Techron formula and charge a few bucks more.

[dirtrider]

40 minutes ago, Paul De said:

Haha, I think the BMW formula is fill their labeled bottle with Chevron's Techron formula and charge a few bucks more.

Morning Paul

 

Yes, that pretty well sums it up. Looks the same & smells the same.  I just haven't been able to figure out if it is standard Techron or Techron concentrate.  

[Skywagon]

DR...I pretty much exclusively run Chevron fuel in my bike.  It has Techron.....In your opinion is that too much Techron?  I do the same for my cars.  Even though it cost a little more I've never had a water or injector problem that I know of...Nope in case someone ask I don't work for or own stock in Chevron.

[Paul De]

Right.  Whatever Chevron formula BMW has in their bottle isn't a problem because Techron is one of the few additives that actually works well as advertised.  My only problem is I have to buy it from BMW or Chevron as an extra cost additive because there are no Chevron gas stations anywhere near me where you get a little bit with every gallon.

[dirtrider]

1 minute ago, Paul De said:

Right.  Whatever Chevron formula BMW has in their bottle isn't a problem because Techron one of the few additives that actually works well as advertised.  My only problem is I have to buy it from BMW or Chevron as a extra cost additive because there are no Chevron gas stations anywhere near me where you get a little bit with every gallon.

Morning Paul

 

You should be able to find Techron (& Techron concentrate) in about any auto parts store. 

[dirtrider]

6 minutes ago, Skywagon said:

DR...I pretty much exclusively run Chevron fuel in my bike.  It has Techron.....In your opinion is that too much Techron?  I do the same for my cars.  Even though it cost a little more I've never had a water or injector problem that I know of...Nope in case someone ask I don't work for or own stock in Chevron.

Morning David

 

If you use Chevron most of the time & buy mostly top tier gasoline then you shouldn't need any extra Techron. A little Techron goes a long way. 

 

I use Techron occasionally in my motorcycles,  especially after traveling for a few days in the back country where the only fuel available is from mom & pop stations with who-knows-what fuel quality and/or how old it is.

 

 

 

 

[Skywagon]

DR...sorry my question wasn't clear.  I buy Chevron premium for my bike.  Should I occasionally buy some fuel without Techron?

[dirtrider]

9 minutes ago, Skywagon said:

DR...sorry my question wasn't clear.  I buy Chevron premium for my bike.  Should I occasionally buy some fuel without Techron?

Morning David

 

No, keep doing what you are doing. Chevron doesn't use that much & it is well mixed in. 

 

The only time I have seen Techron cause any issues is when a rider  adds way too much at every fill-up (like adding a lot with only a 2 gallon fill-up). 

 

Or when using in a motorcycle that has been sitting for long periods & the first heavy dose of Techron breaks a lot of varnish loose & plugs the fuel filter.   (nothing wrong with using Techron to clean an old skunky fuel system but that probably should not be done just prior to leaving on a long road trip) 

[2015 Blue RT]

7 hours ago, Paul De said:

Haha, I think the BMW formula is fill their labeled bottle with Chevron's Techron formula and charge a few bucks more.

LOL, having owned a Corvette, I'm familiar with that concept. We called it the Corvette tax.

 

I put 6.02 gallons of ethanol-free 93 octane (looks like I picked the wrong week to buy gas with the Ukraine invasion spiking oil) in this afternoon (range showed as 35 miles). In the 15 mile ride home, I didn't notice any significant change. For the missing/surging it still gets decent mileage, around 47-49 with rural riding @ 60-65 MPH. This problem seems to be more noticeable the faster the engine turns. On an open stretch, I opened it up to around 5K RPM and it was far more prevalent. I'll try another tank of this next week and see how it does.

[LAF]

23 hours ago, dirtrider said:

Morning Paul

 

You should be able to find Techron (& Techron concentrate) in about any auto parts store. 

I have used Yamalube Ring Free for 25 years in all my cars and bikes.  It was $80 a quart last time I bought it.  I was told many years ago it was concentrated Techron and have used it since.  Cheaper then Auto Zone and I mix it with Startron to treat 5 gallons.  I use some old Stabil bottles that you squeeze and fill the side tube to pour in the tank.

 

I run wide band O2 sensors with a PC 5 and never had a problem in the 8 years I been running it in the RT and GS.  In my 05 Road Glide when I put new heads and cams and pistons and throttle body in everything was pristine except a slight build up on the tops of the pistons.  I always used Yamalube in it. 

 

I don't believe Techron to be the issue. 

 

I never have or will use a Octane booster.  I see no need.  Back in the day when you had a hot car or bike you would go get AV gas in 110 octane.  Also you could pull into a Amoco gas station and pump strait leaded gas at 98 octane. 

 

I wonder if that octane booster threw the bike into a hissy fit?

 

A 2015 does not have any knock sensor in it.  So while there is a bit of wiggle room for the built in maps on the bikes, there is no way it is going to be able to do anything with the extra octane. 

 

I have run nothing but premium unleaded in my 07 LT, 15 RT and now my 17.5 GS and never had a problem with additives.  

 

I wonder if it is just water in the gas.  A slight miss is a hard one but I would start with new fuel as suggested.  And do have a look at your plugs.  While not something that happens a lot the coils have a very distinct feel when seating so make sure that is not the case here,  and remember after checking your plugs that the coils seat properly.

 

Hope it is a easy fix and please let us know what you find.

[2015 Blue RT]

Never made it through the first tank of gas, the bike stranded me at work today & the wife had to pick me up. It ran fine coming in, sat all day under the cover like it usually does, then when I went to leave it started & then immediately died. Check engine light is on. Now it just cranks and doesn't start. I'll run a scan on it tomorrow to see what I can learn about it & will haul it home on my trailer.

 

I have to say I'm REALLY disappointed at this. I could understand if it was a sub $1K used older model bike, but after paying $6K for this I expected a lot better so far as reliability.

[Cap]

You’re disappointed because it ran great for 92,000 miles?  
 

I’m sure you’ll get it figured out, and running great again.  And it will cost you about the same as we all spend to keep our bikes running great, from time to time.

 

Cap

[2015 Blue RT]

The only important mile is the one ahead. For me, I've only had about 2K miles, and per the topic of this thread I can't say it was 100% running great all that time (nor can I vouch for the other 90K miles).

 

I'm disappointed since this expensive (to me) bike stranded me within about 3 months. Out of all the bikes in my signature, only 1 has done this- the second ($900) GS1000G, and that was due to user error.

 

I'm also disappointed that I had to pull my wife 90 miles out of her way when she was on her way to a weekly event with friends.

 

As for cost, if it is bad coil(s), they are around $190 each from what I can tell. That is robbery. I pay less than that for 6x AC Delco brand stick coils.

 

I'm hopeful the MotoScan I purchased will interface OK via the adapter cable and Bluetooth adapter so I can read the code(s) triggering the check engine light. Having read through some similar no start threads here, there was always an event (such as being dropped) that lead to the no start condition. This just happened out of the blue.

[dirtrider]

1 hour ago, 2015 Black RT said:

The only important mile is the one ahead. For me, I've only had about 2K miles, and per the topic of this thread I can't say it was 100% running great all that time (nor can I vouch for the other 90K miles).

 

I'm disappointed since this expensive (to me) bike stranded me within about 3 months. Out of all the bikes in my signature, only 1 has done this- the second ($900) GS1000G, and that was due to user error.

 

I'm also disappointed that I had to pull my wife 90 miles out of her way when she was on her way to a weekly event with friends.

 

As for cost, if it is bad coil(s), they are around $190 each from what I can tell. That is robbery. I pay less than that for 6x AC Delco brand stick coils.

 

I'm hopeful the MotoScan I purchased will interface OK via the adapter cable and Bluetooth adapter so I can read the code(s) triggering the check engine light. Having read through some similar no start threads here, there was always an event (such as being dropped) that lead to the no start condition. This just happened out of the blue.

Morning  2015 Black RT

 

Be a little careful with the MotoScan data that you get, I'm not familiar with the MotoScan itself as I only use a GS-911, but  have worked with a few others that have used the MotoScan to send me data and for some problems/faults  the fault codes that they sent me didn't line up with BMW fault codes for the same failures.    

[2015 Blue RT]

Thanks. I can't drop $300 0n the fancy reader right now. The Motoscan gave me "Fuse active electric fuel pump 21F5E2". Reading some posts online this seems to indicate a failing or failed fuel pump. On a K1600 forum, a member had similar miss symptoms with that code. I'm towing it home today so I'll have some time to look into the problem.

[dirtrider]

47 minutes ago, 2015 Black RT said:

Thanks. I can't drop $300 0n the fancy reader right now. The Motoscan gave me "Fuse active electric fuel pump 21F5E2". Reading some posts online this seems to indicate a failing or failed fuel pump. On a K1600 forum, a member had similar miss symptoms with that code. I'm towing it home today so I'll have some time to look into the problem.

Morning  2015 Black RT

 

That code would make some sense as it does seem to fit your problem. Just don't get so focused on that specific code that you miss something else.

 

Did that bike sit for quite while before you bought it? I'm not sure on the 1200 wethead but the BMW 800 uses an alloy fuel pump that isn't anodized  & those can stick & cause no starts if stored with alcohol-fuel. (I put a small amount of 2 cycle oil in my 800GS fuel tank for last few rides before winter storage to lubricate the pump & prevent sticking).  I also winter-store with non-alcohol fuel   in the tank. 

 

 

 

[2015 Blue RT]

Unfortunately I don't know how long it may have sat, but 87k miles in 7 years is a good sign in that respect. My 1992 GSX had a lot of sitting issues when I got it, to include a corroded fuel tank. It only had 8k miles when it was 20 years old.

 

I need to find out if the RT lc uses a fuel pump controller and how I can diagnose it. I've found a bypass cable that's supposed to make it ridable but have more research to do on the problem.

[dirtrider]

50 minutes ago, 2015 Black RT said:

Unfortunately I don't know how long it may have sat, but 87k miles in 7 years is a good sign in that respect. My 1992 GSX had a lot of sitting issues when I got it, to include a corroded fuel tank. It only had 8k miles when it was 20 years old.

 

I need to find out if the RT lc uses a fuel pump controller and how I can diagnose it. I've found a bypass cable that's supposed to make it ridable but have more research to do on the problem.

Morning  2015 Black RT

 

You will have to look on top of your fuel pump pass-through assembly , I'm pretty sure all pre 2016 1200 wetheads had an FPC (FPE). It's that finned thing with a connector plugged into the top of it. 

 

Those FPC's are difficult to diagnose as a standalone as the problems are usually internal & electronic. 

 

In most cases a GS-911 will give an error code for a failing FPC. 

 

You can also by-pass the FPC & run full 12v directly to the pump as a test. 

 

If you have an amp-meter shunt for your multi-meter then you can monitor the pump operating current to try to catch it when drawing too much current. Without a shunt most household multi-meters will blow the (amperage) overload  fuse.

 

Do NOT run the fuel pump when outside of the tank for more than a nano second as the fuel pump is fuel lubricated & fuel cooled  (gasoline passes through the motor interior when running) 

 

 

[2015 Blue RT]

Thanks for the info and more accurate description. I saw Max BMW calls it a "SET: FUEL PUMP, ELECTRONIC" and it's about $260.

 

I think the path of least resistance for diagnosis is to buy the $36 bypass cable and see if the pump operates. If so, then the controller is bad. This apparently can be done with the pump & tank in place. If it doesn't operate, then the pump is bad.

 

Here's what the site says about it:

On 2005 to 2017 BMW R1200GS, R1200GS Adventure, R1200RT, R1200ST, R1200R, F800GS, F800GSA and F650GS-twin motorcycles, the fuel pump controller can fail due to water infiltration or because of a design flaw, limiting heat sinking, leaving you stranded. Using the accessory socket or an SAE battery connector and this cable as a temporary fix, you can bypass the failed controller and get back on the road.

 

There are a number of positive reviews on their site.

 

I'm also looking at an aftermarket fuel pump:

I also found a site called Quantum Fuel Systems that advertises a compatible aftermarket pump for the RT through 7/2016 ( I think my bike was made circa 12/15). Complete with a seal and a Mahle filter, it's about $85, or $70 on eBay. I also found a Kawasaki site where circa 2020 a member that used to install these for track use stopped doing so due to them flowing fuel if the hose was disconnected (no check valve).

 

This company sells on Amazon, and I've read mostly positive reviews when it comes to using these on BMW bikes. I haven't been able to find one specific to the 2014-16 RT though.

[dirtrider]

11 hours ago, 2015 Black RT said:

Thanks for the info and more accurate description. I saw Max BMW calls it a "SET: FUEL PUMP, ELECTRONIC" and it's about $260.

 

I think the path of least resistance for diagnosis is to buy the $36 bypass cable and see if the pump operates. If so, then the controller is bad. This apparently can be done with the pump & tank in place. If it doesn't operate, then the pump is bad.

 

Here's what the site says about it:

On 2005 to 2017 BMW R1200GS, R1200GS Adventure, R1200RT, R1200ST, R1200R, F800GS, F800GSA and F650GS-twin motorcycles, the fuel pump controller can fail due to water infiltration or because of a design flaw, limiting heat sinking, leaving you stranded. Using the accessory socket or an SAE battery connector and this cable as a temporary fix, you can bypass the failed controller and get back on the road.

 

There are a number of positive reviews on their site.

 

I'm also looking at an aftermarket fuel pump:

I also found a site called Quantum Fuel Systems that advertises a compatible aftermarket pump for the RT through 7/2016 ( I think my bike was made circa 12/15). Complete with a seal and a Mahle filter, it's about $85, or $70 on eBay. I also found a Kawasaki site where circa 2020 a member that used to install these for track use stopped doing so due to them flowing fuel if the hose was disconnected (no check valve).

 

This company sells on Amazon, and I've read mostly positive reviews when it comes to using these on BMW bikes. I haven't been able to find one specific to the 2014-16 RT though.

Morning  2015 Black RT

 

Making or buying an FPC (FPE) by-pass cable might not be a bad place to start as you can always carry that even after your system is repaired in case you ever have a future FPC failure. 

 

If you don't presently have a FPC failure code stored then the FPC is usually OK (not 100% but usually).

 

You can also try  both  https://www.euromotoelectrics.com     or        https://www.beemerboneyard.com     as both carry decent BMW replacement parts. 

[2015 Blue RT]

Thanks DR. I saw the Euromotoelectrics place had a far better price ($175) on the FPC than anyone else. If that part checks out as bad, I'll likely buy from them.

[2015 Blue RT]

Not bad for an hour's work, didn't break anything :

Tank removed with controller in foreground

 

I found the instructions on the bypass cable site were for the prior model, but they served as a guide. The main difference of course being you have to pull the tank to access the controller. Another was the controller screw heads are T10, not T20. Accordingly, I would not classify this as a roadside-level repair as it would be for the earlier models.

 

Now as soon as the cable gets here I can try & bypass the controller. The fuel pump access looks to be a similar setup to various vehicles I've worked on if I need to go that route.

 

If the controller is bad (easiest repair), it can be replaced for around $175.

If the pump is bad (more difficult repair), it can be replaced for around $75.

 

EDIT

While I was there, I also looked at the air filter & saw it needed replaced. I have a new one on the way.

[Cap]

On 3/4/2022 at 4:10 PM, 2015 Black RT said:

If the controller is bad (easiest repair), it can be replaced for around $175.

If the pump is bad (more difficult repair), it can be replaced for around $75.

Nice work.  I realize everyone has their own opinions, and we know what those are like… 😀.  Having said that, if it were me, and my bike had 92,000 miles on it, and I had taken the time to dismantle the fuel tank, I would simply replace both parts with new.

 

just a thought, Cap

[2015 Blue RT]

Yeah, that's what I'm leaning towards doing. I went ahead and ordered the pump/filter combo. I changed fuel filters (2 external pre/post pump) on my GSX annually, it seems like I should do this here as well. I was reading that BMW and Mahle had some sort of agreement about the filters until recently, and this was detrimental to DIY maintenance. The KL 315 filters are now available, so that's good. Looks like they can be had for around $22.x shipped.

[2015 Blue RT]

Also ordered the Euromoto pump controller, should be here Wednesday via FedEx. USPS in an outstanding display of the oxymoron known as government efficiency shipped the bypass cable past my town to one about 140 miles away, and it's departed the same facility there twice now. It was due today, but maybe tomorrow. Seems like as good a place as any for one of my favorite YT videos:

 

 

[2015 Blue RT]

Bypass cable (that bypassed me ;)) made it today. Tested & no start. Apparently the pump is bad. That should be here tomorrow. No word yet on the controller being shipped.

[2015 Blue RT]

Pump & controller arrived today. After pulling the pump assembly, it looks like it will be a fairly easy job. I've taken some pics of the process so I will post them below. Right now I'm on hold due to a technical question about the convoluted plastic tubing- it appears you have to heat the ends and then slip them onto the pump & filter. The old filter had a metal clamp on it, and the kit did not come with that type of clamps. I have sent an email to support to see if I need clamps. There was also a rubber hose, but it was not marked (i.e. SAE 30 R10), and it was too short to connect properly. I noticed the plastic tubing was larger (9mm) on one end than the other (8mm). The filter has an 8mm end while the pump is slightly larger. I had to cut off the old clamp  and then slit the tubing on the filter end to get it to pull off so I could remove the filter clamp. I think the screws were T10.

 

The pump was 100% plug and play though, it popped right in to the housing and the electrical connector plugged right in as well. The kit had a selection of sock filters, there was one about the same size as the OEM part. It also connected easily.

 

A couple of other notes- the filter came off with a tug, and there was an o-ring inside it I had to remove and put on the new one. The old pump has a nub on it by the inlet. I had to push on that while pulling the ears that hold in in place away. Sounds harder than it was, but just pulling the ears and pulling on the pump didn't remove it.

 

Here's the OEM assembly removed, the parts kit, the new pump installed, the fuel filter connector, and the housing with the OEM pump removed.

 

[2015 Blue RT]

The manufacturer got back to me & suggested I use their clamps. Not wanting to keep the bike down, I used a couple of small 11-16mm fuel injection hose clamps. I heated the tubing in boiling water for 3 minutes each end and was able to push them onto the pump and filter.

 

 

 

I found the new screws for the controller were the wrong size for the wethead, so I used the old ones.

 

Got all the parts reinstalled and the tank refilled and it started right up. Now I have to put the tupperware back on and it should be good to go.

[2015 Blue RT]

So after my first 60 mile round trip, the "miss" at higher RPM remains. At this point, I'll just have to live with it.

[dirtrider]

7 hours ago, 2015 Black RT said:

So after my first 60 mile round trip, the "miss" at higher RPM remains. At this point, I'll just have to live with it.

Morning  2015 Black RT

 

You might see if you can get your MotorScan to trap engine data while  riding. (I'm not sure on this with a MotoScan)

 

If you can trap actual fueling control data while riding then we can look at the  Lambda sensor voltages, & Fueling trims while riding  (in)  the engine miss operating range (we might catch something that way).

 

Even something like a stuck exhaust flapper valve can increase higher speed exhaust back pressure giving you a reversion type road-load engine miss. 

[Cap]

Fuel, air, spark...

 

Unless you have a clogged injector, you have fixed your fuel delivery problem.  But after all the discussion of Techron, I assume you have that eliminated as a possibility.  In the process of removing your gas tank, you must have pulled your air filter -- and assuming it was not clogged with a mouse nest (as I have found some times) then your air delivery is probably fine.

 

So, that points to spark.  You replaced your plugs, IIRC.  So, that leaves the coils as a likely culprit for a high-rpm miss.  I know you don't want to throw parts at it unnecessarily... but you could buy one new coil, and swap it in.  Test, swap new coil to other side, test again.  At least that would reduce the cost of the test.  And it is always nice to have a spare coil.

 

If that doesn't eliminate the miss, then there are some other possibilities.  I wonder, for example, have you inspected the timing trigger under the left-side valve cover? 

 

You are very close to having this figured out.  You have the skills, I'm sure you will track it down.  Enjoy, Cap

[2015 Blue RT]

I have been busy with other work, but it seems the problem is getting more noticeable. I connected the Moto Scan app this morning and ran it, didn't see anything unusual while at idle to 3K RPM in the garage (timing, fuel pressure, O2 sensors). I don't see how to capture (record for later analysis) data while riding. I shot a 60 second video (88 MB) of it in the garage and it's too large to attach. I converted it to an audio MP3 file that is 1 MB and is attached.

 

If you listen, it sounds like it is popping or stumbling at idle and as it revs. I tried to run it up to a certain RPM and hold it, but wasn't exact on that since I was also holding the camera.

VID_20220319_104155811.mp3

[dirtrider]

22 minutes ago, 2015 Black RT said:

I have been busy with other work, but it seems the problem is getting more noticeable. I connected the Moto Scan app this morning and ran it, didn't see anything unusual while at idle to 3K RPM in the garage (timing, fuel pressure, O2 sensors). I don't see how to capture (record for later analysis) data while riding. I shot a 60 second video (88 MB) of it in the garage and it's too large to attach. I converted it to an audio MP3 file that is 1 MB and is attached.

 

If you listen, it sounds like it is popping or stumbling at idle and as it revs. I tried to run it up to a certain RPM and hold it, but wasn't exact on that since I was also holding the camera.

VID_20220319_104155811.mp3 1.01 MB · 0 downloads

Afternoon  2015 Black RT

 

I can't tell  a lot from that audio file, it definitely doesn't sound smooth but without a load on the engine they can sound a bit unstable. 

 

We really need road load data on the  lambda sensor voltages, & fueling trims while riding  during the engine-miss operating range to tell much over the internet. 

 

Have you verified the exhaust flapper valve is operating correctly (not just commanded with the MotoScan but verifying that the actual valve operates correctly)? Or just disconnect the cable then wire it fully open then ride the motorcycle. 

 

 

[2015 Blue RT]

I'll have to learn how to do that. I plan on spending some time with my shop manual today.

EDIT- I found it in the Haynes online manual. It's called an exhaust flow control valve. I'll let things warm up a bit before undertaking that.

 

I was also surprised the only test for a coil there (absent a fault code) is pulling the plug and grounding it to the head to see if there is a blue spark. I figured there would be a resistance test, but apparently not.

[2015 Blue RT]

On 3/19/2022 at 11:37 AM, dirtrider said:

Have you verified the exhaust flapper valve is operating correctly (not just commanded with the MotoScan but verifying that the actual valve operates correctly)? Or just disconnect the cable then wire it fully open then ride the motorcycle. 

 

 

 

 

I located the control piece and managed to remove the outer cable. The bell crank moved freely. I used a coat hanger to wire it open, then went for a ride. No difference.

 

As for scanning, I had the great idea to use the larger screen on my Nexus tablet with a screen recorder app, since it is already installed on the bike. Bad idea apparently, as even when I used the same Google account to install the Moto Scan app, it won't let me get past Lite (free) version. It still shows I paid for the ultimate version, so I have an email in to support.

[dirtrider]

On 3/21/2022 at 6:52 AM, 2015 Black RT said:

I was also surprised the only test for a coil there (absent a fault code) is pulling the plug and grounding it to the head to see if there is a blue spark. I figured there would be a resistance test, but apparently not.

Afternoon 2015 Black RT

 

Trying to do a resistance check on those coils is about useless. The secondary side is isolated without a good resistance path (diode) so you really can't measure that. But even if you could, those coils typically fail with the secondary arcing to the internal RFI shield & no way to test for that.

 

There is one sort-of / kind-of test though. If you have access to an old AM radio (remember those), try tuning that to a open spot (no station) then with it turned on  move it around close to each side firing spark plug. If you hear a lot more static on one side  (in cadence with the spark plug firing) then that side has a good chance of having a failing coil (internal arcing).  

[2015 Blue RT]

I sure do remember them! LOL, now that's a high-tech diagnosis method! I don't think I've had a portable AM radio in like 50 years. The closest I could come to that would be the one in my car, and I can't get it close enough. I do have both a frequency generator and oscilloscope (PC based software) if that could somehow help.

 

Not making much headway with Moto Scan. The developer has told me to synch the Google account on the tablet. I did that, and nothing changed. The odd thing is it also shows as Lite/free on my phone where it worked as Ultimate before. I wonder if I tripped some type of app security feature by having it on two devices?

[2015 Blue RT]

The Moto Scan issue somehow resolved itself. After reattaching the control valve cable, cover, and heat shield, I did a short 1/4 mile ride to see if this idea will work. There are no lamba voltage or fuel trim fields, so I used what appeared to be similar (the app was apparently written in German and translated). The screen cap video can't be attached here, but looking at readings at various RPMs here is what I had:

Top to bottom:

RPM

O2 control factor 1 (perhaps similar to lambda voltage?)

O2 control factor 2

Ignition coil closing time in ms (dwell?)

Ignition timing (degrees)

Duration of injection 1 (perhaps similar to fuel trim?)

Duration of injection 2

 

1200

.94

.87

1.78

14.25

2.46

2.42

 

1500

.95

.86

1.82

13.50

3.34

3.30

 

2000

.90

.92

1.84

21.00

3.42

3.44

 

3000

.89

.87

1.82

29.25

2.94

3.00

 

4000

.90

.90

1.80

48.75 (seems really high)

3.20

3.14

 

EDIT

Read up on narrowband O2 sensor readings, and from what I can tell, the readout here is likely volts. It looks like the voltage range here should be .1 to .9, with .9 being richer and they are most accurate from .4 to .8.

 

I'll try to do an actual road test tomorrow now that I know I can capture this data.

[dirtrider]

Morning 2015 Black RT

 

The Lambda control factor is not indicating Lambda (o2 sensor) voltages, it is basically showing the excess oxygen in the exhaust. Anything under 1.0 is showing slightly on the rich side but your numbers look pretty normal. But you also need to keep in mind that your fueling control only has the ability to control (about to)  plus or minus .20.  

 

Same with the Ignition timing (degrees), I have seen that go to over 50° in some cases but without seeing the captured stream I can't tell you if that  48.75° you show is an outlier or normal. 

 

If you can put your trapped road load data into Excel format then PM that to me, THAT, means a lot more as that way I can see (compare) the entire data streams not just a few stand alone data points.   

 

What we REALLY need is as much data (all the functions that you can trap) as possible but we REALLY need to see that data during, or while, the problem is actually happening.