• Welcome to the BMW R18 Forums. Member registration disables ads and allows you to post and share. Register Here.

Hard starting

  • <i class="fa--xf fal fa-check "><svg xmlns="http://www.w3.org/2000/svg" role="img" aria-hidden="true" ><use href="/data/local/icons/light.svg?v=1758297946#check"></use></svg></i> Discussion starter Discussion starter harleyel47
  • Start date Start date
Last edited:
Been done here already btw

laennecr

Thread 'NOCO NLP30'

Did a search and found old posts so here is a new one. Battery died hard today, leaving me to push the Classic - with sidecar - 10 blocks home 😳. Figured it was faster than a tow or getting a trailer. Literally a pain in the ass 😭.
Replaced the OEM, 4 year old AMG battery, with a LiFePO4 NOCO NLP30 ( https://no.co/nlp30 ). Fit perfectly and so far so good. I’ve been using a NOCO NLP20 in my R9t for two years now with zero issues. Anyone else? BTW…. the substantially lighter weight made the actual installation MUCH easier.
  • Like
 
How did this turn into a battery thread, from a hesitation to start thread? Back on track...

First start, cold, engine turns over but will not start at all after about 1500 miles, after being shut down on a hot engine the last time. Starting the engine, not letting it warm up, (kept Cold), then shutting it off, then trying it again 24 hours later, it turns over and starts right up immediately.
 
Pork Rind said:
How did this turn into a battery thread, from a hesitation to start thread? Back on track...
Click to expand...

oh come on, it was quite natural and close enough

Pork Rind said:
First start, cold, engine turns over but will not start at all after about 1500 miles, after being shut down on a hot engine the last time. Starting the engine, not letting it warm up, (kept Cold), then shutting it off, then trying it again 24 hours later, it turns over and starts right up immediately.
Click to expand...

You lost me.
When/how, after ´cold engine not starting at all´ did you get to starting, not warming up??? So it did/does start from cold?!
 
Petrus said:
oh come on, it was quite natural and close enough



You lost me.
When/how, after ´cold engine not starting at all´ did you get to starting, not warming up??? So it did/does start from cold?!
Click to expand...
https://www.r18forums.com/threads/hard-starting.365/page-3#post-58184

An aged battery problem causes turnover speed problems, critical with fuel injected engines.

This is a turnover no start problem and seems to be related to the next time you start after cooling down 24 hours from a hot engine condition shutdown, vs a cold engine condition shutdown.
I am familiar with the problem, it happened on my test ride of a 2022 R18 B in Sturgis SD in 2023 on a 2022 model.

It also happened on a 2023 R18 B 7019 optioned bikes that the YouTube gal Her Two Wheels bought, while filming. She has since deleted and re edited that video, since she was a BMW Ambassador, but hers was problematic too. She traded it in this summer, after trying for months and months to sell it herself, privately, and took a hard $ hit on trade in, from what I've heard, didn't sit well with her.

Batteries aren't the problem.

I have my own theories on it. I suspect there is an inline fuel pressure sensor to the injectors, that at start up, send a reading parameter to the ECM software what the fuel pressure is when the ignition gets turned on. If the engine is put away hot, the fuel pressure leaks down to an inadequate start and run level. Hitting the starter rotates the crank enough that something is now feeding from the fuel pump fuel pressure to the injector line that is at an adequate level. The starting fuel pressure level when first turned on is in "Memory" by the ECU. Once you quit trying the start button to turn the motor over, the ECM takes a new fuel pressure reading. Since the motor has now turned over, the fuel pressure is now correct and within parameters to now allow the ECM and crank sensors to fire spark to the engine. The ECM if the fuel pressure is inadequate, is doing a no spark to the ignition system. If fuel pressure is adequate, the ECM does allow spark to the ignition system. Even if fuel pressure was low in the fuel injector system, the engine would at least "pop", albeit the motor wouldn't fire up. There is something that's either leaking down the fuel pressure after sitting, and ECM parameters when it sees low or no fuel pressure isn't providing spark. ANY bike with a fuel injection system and a battery with enough juice to spin the motor over, will fire up on the first engine revolution, if all parameters are met by sensors feeding the ECM.

The bikes always fire right up after the turnover with no start, the next time you press the start button.

Maybe this is BMW replicating the Harley Davidson Hard Start conditions on the R18 ? LOL!
 
Last edited:
What I responded to still makes no sense:
You shut it down hot and then when cold it does not start.
Right. We are at does not start when cold no?!
Ah well... never mind.

As a generic observation, valve play can shift a bit when the bike is being run in and it can affect starting.

Back to the battery, a higher cca will kick the engine a round a bit harder which increases compression end temp just that bit, making the mixture easier to ignite. So yes a newer, different battery can make for easier starting.

The cr thus the heat source being the same, this is about that with a cóld engine the inlet tract and de large aluminium combustion chamber absorb heat amd heat is a prerequisite for ignition.

On a side note I find it going against my old skool grain that the lighting of many modern vehicles cannot be switched off for starting.
 
Petrus said:
What I responded to still makes no sense:
You shut it down hot and then when cold it does not start.
Right. We are at does not start when cold no?!
Ah well... never mind.

As a generic observation, valve play can shift a bit when the bike is being run in and it can affect starting.

Back to the battery, a higher cca will kick the engine a round a bit harder which increases compression end temp just that bit, making the mixture easier to ignite. So yes a newer, different battery can make for easier starting.

The cr thus the heat source being the same, this is about that with a cóld engine the inlet tract and de large aluminium combustion chamber absorb heat amd heat is a prerequisite for ignition.

On a side note I find it going against my old skool grain that the lighting of many modern vehicles cannot be switched off for starting.
Click to expand...
It does start when cold, but only when it had a cold shut down and then you wait 24 hours and start it up again. Reread the protocol in the link I mentioned, for what does work, and what doesn't work, for troubleshooting. Something changes when put away and shut off hot, and then started cold, 24 hours later, that causes the motor to turn over but not catch and start running. You can start the motor for just a bit, shut it off, motor still cold, and come back 24 hours later, and it starts right up this time, first push of the starter button. Something ends up missing to complete ignition when put away hot, and then waiting 24 hours and starting up on a cold motor. There's no ignition or something prevents the fuel pressure from the fuel pump from pumping up the injector lines to operating fuel pressure, until the motor spins over from pressing the start button. Or there is a software parameter that is not being met upon startup, under required specifications, to allow ignition to occur.
 
Petrus said:
Not on mine.

Not experienced any starting oddity not related to user behaviour 🫣
Click to expand...
How many miles on it? Any injector cleaner? Ever ran fuel with ethanol through it?

I'm looking for data and not blaming ethanol. My feeling (without checking fuel pressure in the problematic condition) is that it feels/sounds exactly like an engine that has no fuel.

I don't know what BMW does on the fuel side for how much fuel is sprayed with each button press. Given that it has no problem cold/cold and does have a problem hot/cold leads me to believe there is a fuel leakdown issue with a loss in pressure in the fuel circuit. This logically make sense to me why a tiny starter bump on the hot/cold condition allows a second tiny starter bump to get it running. The first one primed the fuel circuit. I've tried it letting the starter run on the hot/cold condition for 10 seconds or so and it feels/sounds like an engine with no fuel. I just don't know what interval BMW has programmed to spray additional fuel. If you held the button down for 60 seconds with the spark plugs removed how many times would the injectors spray fuel in 60 seconds?

Edit: I suppose the lack of ignition would sound/feel the same but I'd expect to have a rich fuel smell unless like @Pork Rind said they've got logic in place to cut fuel and ignition in a corner case condition that's actually causing this problem due to a conditional logic error in ECU microcode.
 
Last edited:
Just a thought as the failure to start up first time has been discussed previously on other topics. All the points flagged here are valid but I believe that if the above were the root cause, then it would affect all R18 engines. Now, for those having issues starting the bike either hot or cold, can you remember if you switched off the bike by using the big red kill switch or the small black power button?
I believe it has been established that switching off the bike using the red kill switch can cause issues when you next start the bike.
I use the bike minimum 3 days a week all year round and there is a gap of 24hrs minimum between usage. I exclusively use E5 fuel and my garage is not heated. During the summer there is no issues obviously but during winter is fecking cold when I go to the garage at 5:30am and my bike starts first time every time. I use the power button to switch on and off. Just a thought.
 
Anibal said:
Just a thought as the failure to start up first time has been discussed previously on other topics. All the points flagged here are valid but I believe that if the above were the root cause, then it would affect all R18 engines.
Click to expand...

Imo the root cause of many a gripe ranging from starting issues to production stop, noisy by desígn, including even overheating of all things, is a barely hidden agenda. My appologies to the ones whom dó have a genuine issue.
 
Petrus said:
Imo the root cause of many a gripe ranging from starting issues to production stop, noisy by desígn, including even overheating of all things, is a barely hidden agenda. My appologies to the ones whom dó have a genuine issue.
Click to expand...

In the case of youtube reviewers, that seems to be universally true of the "5 things I hate about my new diamond ring" type people expecting to drive clicks/views. There were a handful of them (>= 100k-200k subscriber channels) who got free bikes in exchange for keeping them for a couple of years and doing basically paid promotions of the bike while subtly hating on it.

The R18 was widely hated by the youtube crowd for all the wrong reasons. They hated it because it wasn't a Harley, and spent little time with it understanding any real shortcomings. The only real thing to hate on in my experience is the suspension, which can be easily resolved. This hard/no start issue we are discussing has a reliable workaround so it's not the case where BMW failed. For me, it's more about this being an easy annoyance problem that BMW can acknowledge and solve if we can root-cause it for them. From my testing, and the reproducibility of the issue, it's not the case of "oh that's a characteristic of this bike" flat rate mechanic, warranty aversion advice. Bike characteristics rarely show up en masse at 3k miles. Back in the day Ford Pinto cars had engines and interiors that overheated when rear ended at any mileage :)
 
Anibal said:
Just a thought as the failure to start up first time has been discussed previously on other topics. All the points flagged here are valid but I believe that if the above were the root cause, then it would affect all R18 engines. Now, for those having issues starting the bike either hot or cold, can you remember if you switched off the bike by using the big red kill switch or the small black power button?
I believe it has been established that switching off the bike using the red kill switch can cause issues when you next start the bike.
I use the bike minimum 3 days a week all year round and there is a gap of 24hrs minimum between usage. I exclusively use E5 fuel and my garage is not heated. During the summer there is no issues obviously but during winter is fecking cold when I go to the garage at 5:30am and my bike starts first time every time. I use the power button to switch on and off. Just a thought.
Click to expand...

I use the red kill switch when rolling to kill it since the power button does not work in that case. When it's not rolling, I'm about 50% power button and 50% kill switch and almost never just dump the clutch with the brake on to kill it. I would expect to have had the no start problem on the Test A cold/cold condition at some point along the way due to my randomness in killing the bike if the switch or button was causing the issue.
 

Test Descriptions​


Test A: Ambient Temperature​

  1. Start the R18 in the garage and immediately turn it off after approximately 5 seconds.
  2. Let the bike sit for 24 hours in the same conditions (e.g., garage).
  3. After 24 hours, check if it starts from the first button push.

Test B: Operating Temperature​

  1. Start and ride the R18 for a minimum of 30 minutes to ensure it reaches operating temperature.
  2. Let it sit for 24 hours in the same conditions (e.g., garage).
  3. After 24 hours, check if it starts from the first button push or if it requires the two-start method.

Modifications to Test B​

  • Remove the fuel cap and observe the results
  • Remove the evap canister and observe the results
  • Monitor fuel rail pressure with a gauge or use ECU diagnostics
  • Remove a spark plug or use ECU diagnostics to monitor spark
**Note**: Fuel levels, types, grades, etc., do not impact these tests. The hypothesis is that when the R18 is hot, it causes the injector to leak down, leading to air in the system leading to an initial no start condition.

Important Considerations​

Both Test A and Test B require a 24-hour sitting period. Simply heating the R18 and attempting to start it isn't helpful, as it will start right up without the necessary cooling time for the injector to leak down.

Ruled Out Root Causes​

  • New battery
  • Fuel load
  • Fuel octane
  • Fuel grade/type (E10, ethanol-free, 86, 87, 89, 90, 93, etc.)
  • DWA settings

​

Test Matrix​

Test DescriptionMethodologyObservations
Test A: Ambient TemperatureStart for 5 seconds, wait 24 hours, check startFirst button push success
Test B: Operating TemperatureRide for 30 minutes, wait 24 hours, check startFirst button push fail, second button push success
Modification B1Remove fuel capResults
Modification B2Remove evap canisterResults
Modification B3Monitor fuel rail pressure or ECU diagnosticsResults
Modification B4Remove spark plug or monitor spark via ECUResults
 
Last edited:
u20251009 said:
I use the red kill switch when rolling to kill it since the power button does not work in that case. When it's not rolling, I'm about 50% power button and 50% kill switch and almost never just dump the clutch with the brake on to kill it. I would expect to have had the no start problem on the Test A cold/cold condition at some point along the way due to my randomness in killing the bike if the switch or button was causing the issue.
Click to expand...
Not sure I followed the first bit but did you mean you use the red emergency kill switch whilst the bike still rolling, i.e, moving?
The way I stop my engine is by pressing the power button situated on the right handlebar control cluster. By then I have already entered my garage, came to full stop and gear box in neutral. It works. The only thing I have not done at this point is put the side stand down as I like to keep the engine running on idle for about 5 seconds in the upright position. This is to do with an old habit earlier boxer engines had to smoke a bit on the left cylinder due to small amounts of oil entering the cylinder head when the bike was left on the side stand and then switched off.
 
Anibal said:
Not sure I followed the first bit but did you mean you use the red emergency kill switch whilst the bike still rolling, i.e, moving?
The way I stop my engine is by pressing the power button situated on the right handlebar control cluster. By then I have already entered my garage, came to full stop and gear box in neutral. It works. The only thing I have not done at this point is put the side stand down as I like to keep the engine running on idle for about 5 seconds in the upright position. This is to do with an old habit earlier boxer engines had to smoke a bit on the left cylinder due to small amounts of oil entering the cylinder head when the bike was left on the side stand and then switched off.
Click to expand...
Right, the only way to kill the bike when rolling is to use the red kill switch. I do this regularly when pulling up to stop lights. If you are rolling and press the black power button nothing happens.

You brought up a 4th way to kill the bike (which I have done several times) is to let the side stand down while in gear.

Another thing I do at stop lights is to have the bike in gear so it doesn't roll, hold down the red starter switch, then pull the clutch in when the stop light turns green. This works on the BMW and KTM I have but not on my FTR.
 
Seems counterintuitive to switch off the bike when still moving. Even more so using the emergency button.

I put it in neutral and push the black on/off power button. Always, anywhere so also riding it into the garage.

The only thing I very occasionally do on the roll before stopping is going from 2nd to neutral.

Have kicked the side stand out once when still in gear; dubbed the result the geriatric fail safe.
 
You must log in or register to reply here.
Back
Top