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Starting Issue


malcolmblalock

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malcolmblalock

I have a new (new to me) 09 RT that has a quirk on startup. This is the quirk: When I press the starter button, it will fire, and the engine will catch very briefly (half second or so) and then immediately die. Pressing the starter again, it will fire up, the engine catches, and it will run. It happens the first time it is started each day, but only once per day. On subsequent startups during the day, the engine catches and runs as soon as the starter is pushed.

 

I also have an 05 RT. It starts first press, every time, and never dies on startup.

 

I've been around quite a few other 1200s and haven't noted a problem like mine; the others always fire up and run as soon as the starter button is pushed. So, something is different about my 09 RT.

 

Anyone have any ideas on what's causing this? I haven't taken it to the dealer to check out, but it's still fully warrantied.

 

Suggestions or comments are welcome.

 

Thanks in advance for ideas...

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I would look at the quick release fittings on the fuel tank/fuel pump to make sure they are seated and the hoses aren't pinched. Also take a look at the fuel pump controller electrical connections and the o-ring seal. This will at least help to rule out the simple stuff.

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I had this problem and it turned out to be a failing battery. It eventually got worse to when on the first start it would hang, and reset the clock. Push again and start. Until one day, click, click, click. I should have read the symptoms sooner and replaced the battery. Would have saved some grief.

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malcolmblalock

ddreger, thanks. I was wondering about battery; the battery is definitely weak. If it sits out in cool to cold weather overnight, it is very sluggish turning over. Took it to the dealer a couple of weeks ago, had it checked, and they said it was ok. But it had been on a battery tender prior to riding 30 minutes from home to the dealership, so it had a chance to start out with a full charge as well as to charge on the ride there.

 

Will take it back while the warranty is still good, and, if necessary, pester them until they recognize the problem.

 

Hopefully that will solve my startup isssue.

 

If others have thoughts or similar experiences, I'd love to hear from you as well.

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Afternoon siman00

 

My last 2009 RT did the very same thing when new (and) it was cold outside. A start then a quick stall followed by staring just fine the rest of the day. It was just fine in warmer weather and only stalled when cold started in fairly cold weather.

My workaround was to just hold the throttle slightly open when starting the first time in cold weather, then no stall after start.

 

Here is the strange thing, I’m not sure when or why the starting problem went away. By the onset of cold weather on the second year the problem was completely gone.

After the bike got some miles on it the starting problem was just no longer there.

Now that could be due to engine break-in so it had less friction just after cold start, or the fact that I changed from a 20w50 oil to a 15w50 motor oil (less cold oil drag in the engine), or the fact it had been in a few times for warranty repairs (when the dealer’s computer is hooked up to a bike the dealer usually just goes ahead and installs any BMS-K and ZFE updates.

 

In any case if your bike is still low mileage give it some time for the engine to loosen up, maybe try a different engine oil, and next time your bike is in for service ask if there are any computer updates for your bike.

 

I doubt it is the battery as it seems to crank over well enough to get it started, it just stalls once started (not an indication of a battery issue).

 

In the mean time try holding the twist grip open (just slightly) during cold start and I bet you will find it stays running.

 

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In the mean time try holding the twist grip open (just slightly) during cold start and I bet you will find it stays running.

 

Good suggestion. I find that my '05 RT starts much faster if I do this, particularly in cold weather.

 

Jay

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malcolmblalock

dirtrider, I had thought of holding the throttle open just a bit, and it has not helped. On second try, if I open it a bit, it seems to run better.

 

It acts just like a motor with a manual choke. They won't stay running without more fuel. This seems to act the same way.

 

I've read about so many weird things that somehow seem to go back to battery problems, and with my battery chronically weak, I was hoping that the battery was indeed the problem.

 

I know I can work around it, but it shouldn't be necessary. A fuel-injected engine working properly starts first try every try. My cars do this. My truck does this, My Vstrom did this. My 05 did this. Only my 09 won't start on the first try...

 

I may swap batteries just to eliminate or confirm the battery problem.

 

I'm still open to ideas.

 

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Evening siman00

 

A low battery or battery problem would show up on initial engine cranking not once the engien is running. Once it fires the battery is relieved of cranking load so the voltage automatically increases.

All my 1200 BMW boxers have cranked like they have a weak battery when the engine is really cold.

 

Try opening the throttle slightly more to see if that will help it stay running on cold start. Also hold the clutch lever pulled in to take the thick trans gear oil drag off the engine on cold start.

 

If you have over 10,000 miles on that bike and it still won’t stay running on initial cold start take it in to the BMW dealer and leave it overnight so they can cold start it themselves.

Might actually have problem like a failed or disconnected AIT air temperature sensor or not have the latest computer update in it or even have low starting fuel pressure, maybe an air in fuel line problem, or a malfunctioning idle stepper motor

 

If it still starts then stalls, you might do a test by turning the key on for about 5 seconds (do not start), do this 3 times then try cold starting like usual. That will run the fuel pump 3 times and purge any air out of the fuel lines. If it then starts better tell your dealer this as that might help point them to air in the fuel lines on initial starting.

 

These new BMW boxers do run mighty lean just after cold start to prevent converter damage so all has to be right including cold engine parasitic drag for them to stay running.

 

Like I said in the post above my 09 did the same thing when new so what you have isn’t something new. The only thing I can’t tell you is what happened to mine to make the start/stall go away other than what I mentioned in at post. But mine would stay running if I held the throttle open far enough on initial start.

 

 

 

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I had a similar starting issue with my 07 RT after its 600 mile service. It started fine before that in December and January cold Colorado weather. After the service it would not start unless I held the throttle open for about 20 seconds. I made a movie of the bike's behavior and put it on a USB thumb drive and gave it to the dealer so they could see what it did. That helped a lot so they could see what I was talking about and share it with others. After initially trying to explain it away (they said I wasn't holding the starter button long enough), they kept messing with the software with no results. The dealer had the bike for a least a month of time on several separate occasions trying to fix it, and supposedly they were in touch with BMW Germany to try to diagnose the problem. They also replaced the fuel injectors among other parts. Finally they gave up and said they were unwilling to do anything more. So much for warranty! I was disappointed in their lack of diagnostic skills beyond looking at what their computer tools said. I did not see much logic in the way they approached the problem either. They just kept updating the ECU software, which I don't think has anything to do with the problem. How could it if two bikes running the same software don't have the same problem? It must be something else.

 

The problem only happens when the bike sits overnight in cold weather, like < 50 degrees. If its started once during the day even in cold weather it seems to start fine after that. During the summer months the problem goes away entirely, and the bike starts just fine even from sitting overnight.

 

My theory is that there is an air temperature sensor not functioning properly, so the engine always thinks it is hotter than it really is and does not supply a rich enough mixture for a cold start. I don't think the sensor is broken but just miscalibrated like many thermometers can be, off by several degrees. So it does not show as failed but nonetheless feeds incorrect data to the ECU. I suspect it is the air temperature sensor that is planted in the air intake box housing. That part costs $25 for a new one, and it seems it is a very common part, used in all BMW motorcycles and also all their cars. Part number 13621739510. I'll be trying a replacement in the next month or so and I'll let you know if it works out.

 

Bill in Denver

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Morning Bill

 

Before spending the money on a new AIT (air intake sensor) you have two simple options. One is to disconnect yours and use a simple ohmmeter to measure the resistance across your OEM sensor.

At about 62°f you want to see around 7.25k ohms and at 40°f you want to see about 12.7k ohms. (just in the ball park is plenty close enough)

Those intake sensors seldom if ever fail and when/if they ever do they usually go open or shorted not out of calibration.

 

There is a little issue that can crop up and that is if an AIT connector terminal isn’t making good contact or disconnected. The fueling computer needs to see a temperature reading within the range it knows is believable or it will just substitute a nominal (usually around 70°F) generic value for starting and engine operation.

 

If you do have a failed, disconnected, or other air intake temperature problem I can’t believe the dealer didn’t find it as the intake temp is plain as day on the their test computer and on an overnight cold start should match (or be mighty close anyhow) to the oil temperature sensor on cold soak pre start.

 

One other thing you can do as a quick test is just disconnect the intake air sensor in your air box then insert a plain ¼ ohm 15K resistor between the terminals in the wire harness side plug. If it won’t start and stay running on a 15K resistor then your cold start problem definitely lies in another place.

 

I see in your post above you mention that the same intake air sensor is used in all BMW cars and motorcycles. I can’t speak on the car side but while it is true that the fuel injected motorcycles do use (an) intake air sensor the resistance value string is MUCH different between the 1200 hexhead and the old oil head (not even close at sub 40°f temps). They are also not interchangeable on their mounting as the oil head uses a threaded screw in sensor and the hexhead uses a “O” ring seal with a plastic snap in trigger retention system.

 

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Don_Eilenberger
Evening siman00

A low battery or battery problem would show up on initial engine cranking not once the engien is running. Once it fires the battery is relieved of cranking load so the voltage automatically increases.

 

While the voltage increases - the actual alternator output with a cold engine, idling, is likely to be below 12.6V (where the system is now running off the alternator.) If you have a weak battery - the system voltage may drop to the point where the ECU decides to protect things and shut the engine down.

All my 1200 BMW boxers have cranked like they have a weak battery when the engine is really cold.

 

Try opening the throttle slightly more to see if that will help it stay running on cold start. Also hold the clutch lever pulled in to take the thick trans gear oil drag off the engine on cold start.

Good idea since the increased RPMs will allow the alternator output to exceed the battery voltage. Thing is - the stepper motor controlled idle adjusters should make this adjustment for you. That seems to be the case with my bike - I've never had to increase idle speed manually to get it to continue running (and I ride down into 30F sort of temps..)
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Evening siman00

A low battery or battery problem would show up on initial engine cranking not once the engien is running. Once it fires the battery is relieved of cranking load so the voltage automatically increases.

 

While the voltage increases - the actual alternator output with a cold engine, idling, is likely to be below 12.6V (where the system is now running off the alternator.) If you have a weak battery - the system voltage may drop to the point where the ECU decides to protect things and shut the engine down.[

All my 1200 BMW boxers have cranked like they have a weak battery when the engine is really cold.

 

Try opening the throttle slightly more to see if that will help it stay running on cold start. Also hold the clutch lever pulled in to take the thick trans gear oil drag off the engine on cold start.

Good idea since the increased RPMs will allow the alternator output to exceed the battery voltage. Thing is - the stepper motor controlled idle adjusters should make this adjustment for you. That seems to be the case with my bike - I've never had to increase idle speed manually to get it to continue running (and I ride down into 30F sort of temps..)

 

 

 

Morning Don

 

If the battery were that weak it wouldn’t start to begin with as the heavy starter cranking draw would make existing battery voltage even lower than after key release. After cranking key release the system voltage would HAVE TO increase not decrease.

 

On the ECU shutting the engine down- The ECU would do just the opposite. If it sees falling system voltage it increases the injector pulse width to make up for slower and less active pintle lift due to lower injector supply voltage. It also adds counts to the IAC steppers to try and increase the idle RPM to increase alternator RPM (Per BMW this went into to the 1200RT sometime in the 06-07 time frame).

 

The ECU always tries it’s darnedest to keep the engine running within a safe operating parameters. As long as the steppes don’t run out of travel and the fuel pump has enough voltage to keep making pressure it will try to stay running. Now that doesn’t mean it can always react fast enough to do that therefore an engine stall.

 

 

 

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malcolmblalock

I'll try to clarify the symptoms again. Overall, the battery acts weak when starting the bike from sitting overnight. If I have the battery tender on, it spins the engine just fine. A little more sluggish when really cold (30 degrees or so), but that would be expected of any battery. If I don't use the battery tender, it will just barely turn the engine over enough for it to "hit" and start very briefly (1/4-1/2 second, my estimate). Then the engine dies. When I hit the starter button again, the engine catches and it starts. It runs sluggishly for maybe 15 seconds, and then runs fine after that. It acts like an engine with a choke, and the choke not in use.

 

So, there are two issues in my mind--weak battery and won't stay running on first start. Subsequent starts are fine 100% of the time until the next morning when it repeats the same thing.

 

Bike is 09 RT. 14,500 miles. First put into service 4/09. I am 3rd owner. Bought originally in Illinois, second owner in Michigan. I bought in August and live in NC.

 

Does this information help?

 

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Evening siman00

 

How does it act on first cold start when started with the battery tender on it all night?

 

How does it start after sitting all night in warm weather?

 

At what temperature will it stall on cold start or at what temp will it stay running?

 

How does it start if you cycle the ignition switch on and off for 5 seconds each, 3 times before cold starting?

 

How does it start if you disconnect the battery (before cold starting) for 30 seconds, then reconnect it, then turn the key on (do not start) then FULLY open and close the throttle twice. Then start the bike?

 

Does leaving it on the side or center stand effect the cold starting?

 

Are you holding the clutch lever in while cold starting?

 

Does the engine stall just as the headlight comes on after engine start?

 

How far do you need to hold the throttle open for it to stay running on cold start?

 

Maybe the answer to the above can help us help you a little more.

 

Like I said, my 09 acted almost exactly like yours is now when new but it went away for one of the reasons I mentioned in my first post.

 

 

 

 

 

 

 

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Used to have the same issue with a COLD GS. I think D.R. has the clue with the throttle relearn". On my GS if it didn't catch the first try I'd turn the key off, then turn it back on and slowly do the throttle 2-3 times, then start it. That never failed me.

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Good logical advice, DR, thank you. If I may ask, how did you find those resistance/temperature values? I couldn't find anything anywhere on that. I was a tad afraid to test the sensor thinking that maybe putting a small amount of ohmmeter current across it would fry it, but since you have done that I will give it a try. And I am sure I could scare up a 15k resistor. What you are saying makes sense though, my bike starts fine with temperatures of 70 degrees or so and above, so even if the sucker is non functional it ceases to be an issue in the summertime because the bike is assuming a correct value.

Like they say even a broken clock is right twice a day...

 

BTW the sensor in BMW cars is the same part number as the one in the RT, and from the pictures it appears to be the same part. I have an R1100R too so I hear you about the old sensor being different, it is.

 

Bill in Denver

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Morning Bill

 

 

I have a run a resistance map of temperature vs resistance on both the 1100/1150 screw in temperature sensor and the later 1200 hexhead temperature sensor. Not at all temperatures but over enough range to get a pretty good map of each.

 

FWIW I was working on an inverse type of intake temperature sensor spoofer (something like the FRK).

 

I way very surprised that the hexhead used a different resistance vs temperature than the older oil heads did.

 

Don’t worry about hurting that sensors with a simple ohmmeter as those things are pretty hardy. They are actually pull down sensors so don’t SEND a resistance to the ECU but rather are fed a very small voltage through and internal ECU resisted circuit and the IAT sensor pulls that down then the ECU looks at the “voltage” on that circuit.

 

The only thing to keep in mind when measuring is if using a cheap or older low impedance meter it can skew the resistance data a little due to meter loading.

 

Even with an expensive high impedance meter I could only get close on resistance vs temperature. I could get a very precise resistance reading but didn’t have the means to get a very precise temperature reading so at the colder end the difference of only a ¼ degree f could be hundreds of ohms. Not a big deal but put some ripples in my data.

 

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DR, you got too much time on your hands! But good for me that you do, thank you for the info. Let me guess, are you an EE?

 

I wish we could compile this information somewhere other than this Q&A discussion format. It would be nice to have testing parameters for all the sensors on the bike, so you could tell whether they were good, bad or something in between. Manuals never seem to go into enough detail for that kind of thing.

 

I am not familiar with one term you used: What is am FRK?

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malcolmblalock

Well, I decided to let the dealer check it out again. BMW Roadside Assistance picked it up yesterday and delivered it to the dealer. Going to check out battery, fuel pump, injectors, and computers. Hope to hear back mid-next week. Will update when I have diagnosis...

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malcolmblalock

Well, the dealer kept the bike for a week, cold starting it daily and checking the computer. He says everything is in specs and that my problem may be due to using more voltage at idle than the alternator can make. I absolutely agree that with Motolights on (which stay on 100% of the time the bike is running) and the Autocom and the Garmin SP 2720 on, I am using more voltage than the alternator makes.

 

The problem with that is that the bike idles for very brief periods between long (3o minutes to 4 hours of running at 3-5K rpm. So, I don't buy the assertion that the problem is due to me using too much voltage with my accessories. He also insinuated that the Gerbings connections made it worse (he didn't ask if I use the Gerbings--I've used the jacket once on a 3.5 hour ride.)

 

He finally suggested that maybe I needed a higher output alternator to solve my problem. He did check the output of the alternator and said it was within specs.

 

I assert that with the stock alternator I have plenty of output to handle Motolights, an Autocom, and the GPS AND MUCH MORE!. My Vstrom managed those items with no problem with a much smaller output generating system.

 

I don't buy any of it at all. The 05 RT never acted like this one, even one time.

 

So, I'll pick it up next week and ride it!

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Well, the dealer kept the bike for a week, cold starting it daily and checking the computer. He says everything is in specs and that my problem may be due to using more voltage at idle than the alternator can make. I absolutely agree that with Motolights on (which stay on 100% of the time the bike is running) and the Autocom and the Garmin SP 2720 on, I am using more voltage than the alternator makes.

 

The problem with that is that the bike idles for very brief periods between long (3o minutes to 4 hours of running at 3-5K rpm. So, I don't buy the assertion that the problem is due to me using too much voltage with my accessories. He also insinuated that the Gerbings connections made it worse (he didn't ask if I use the Gerbings--I've used the jacket once on a 3.5 hour ride.)

 

He finally suggested that maybe I needed a higher output alternator to solve my problem. He did check the output of the alternator and said it was within specs.

 

I assert that with the stock alternator I have plenty of output to handle Motolights, an Autocom, and the GPS AND MUCH MORE!. My Vstrom managed those items with no problem with a much smaller output generating system.

 

I don't buy any of it at all. The 05 RT never acted like this one, even one time.

 

So, I'll pick it up next week and ride it!

 

Why is is so hard for people to say they just don't know? So they just make stuff up.

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That is an unfortunate quirk... but, IMHO at least, one you can live with as it is predictable. You would think BMW could figure it out. I think every vehicle I've owned has had a quirk or two.

 

 

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That is an unfortunate quirk... but, IMHO at least, one you can live with as it is predictable. You would think BMW could figure it out. I think every vehicle I've owned has had a quirk or two.

 

 

It's FM.

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This problem sounds familiar. My 08 RT that is same as your 09 took a crap load to crank in cold weather and didn't like to idle on the initial cold start, sometimes dying, until the second winter of year round use- way too much drag from the very tight motor and a stock battery that is very marginal in ability to deliver enough current to get the starter up to a fast spin in cold weather. With the very lean mixture, trying to open the throttle on the new cold motor simply stalled it unless goosed gently a few times.

 

Good news is it will get a lot better when you get enough miles if yours has the same cause as mine. Cranking and cold idling improve a lot on a fully broken in motor. And the stock battery will have an easier time spinning the motor. Mine starts and runs fine now on starts in 20 degree weather entering its third winter with the original stock battery. I use a Battery Bug to keep an eye on what I consider a poorly chosen stock battery and an Extreme or YUASA charger for maintenance.

 

Ways to address the problem

1) Put the battery on a maintenance charger between cold weather uses even if only overnight. Resting voltage for most chargers is around 13.7V, better than the 13.2 or less you'll have otherwise when you hit the button the first time.

2) When you replace the battery, get anything better than the overpriced stock battery. There are several possible choices.

3) An oil lighter than 20W-50 dino juice is preferrable in really cold weather. Synthetics pump better and may assist starting a little, also - it is believed by racers that syns have less parasitic loss even at same viscosities than dino juice of similar grade- plenty of dyno work seems to support it and virtually all use syns in every piece of the driveline for that property and for increased heat resistance.

4) Keep the clutch in to reduce load

5) I wonder if a BoosterPlug or similar would add enough fuel to help some on a cold start. Only a "maybe", at best, I suspect.

6) Rack up miles when you can. Its the best fix.

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