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Discussion Starter · #1 ·
Haven't had a need to call out to the forum for a while with a problem, but might need some help with this one.

Rode the LT to get its annual registration check today, then home, then to the supermarket and parked in an underground parking area. All up no more than 10kms distance. Bike started fine each time.
Go to leave the supermarket carpark about 30 mins later, and the bike won't start... turns over OK, but refuses to fire. Check the stop switch isn't actuated... sidestand isn't down as its on the centrestand. It did this once to me a couple of months ago, in same underground carpark.... at that time I bumped it down the next ramp but it wouldn't start... but then it key-started OK.
So tried the same trick today, but no luck... will not fire up... tries to.. sometimes get a low rumbling like its almost running but won't kick into life. So left it and caught a bus home.

Keep the LT on trickle charger at home, but haven't been riding a lot and mainly short distances when I do.
Installed a new Motobatt AGM battery 12 months ago, voltage reads around 12.7. Filled with fresh fuel about a week or so ago.

Went back tonight after wife got home with car, took a spare "charged" battery and jumper leads.... same deal. Thought it was going to rumble into life a couple of times, had a couple of small backfire "bangs"... but still no dice. So tonight I've given up.

I'll take my little bike back down tomorrow with a laptop and GS911, and some tools, spare battery etc, see if I can figure out whats gone wrong, but would appreciate some tips on things to look for, besides the obvious like:
  • not in gear,
  • stop switch off (I rarely use it anyway)
  • sidestand not down (maybe I'll flick it up and down and make sure that switch isn't stuck?)
  • listen for fuel movement (although I've never been able to hear it before)

What aren't I thinking of... its almost like there's a kill switch activated......???? (There's no alarm on this bike)

And it's not in an easy spot to get hauled out of without the help of a couple of hefty mates (we've been in lockdown for a COVID breakout in Sydney for 48 days straight now, so that isn't happening anyway), certainly probably couldn't get it on a trailer down there... and van wont fit down there either... I get it moving or it ain't moving. :(

Any tips appreciated... I'll check in, in the morning. Cheers guys!
 

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I would remove the fuel cap and look for swirling in the tank when the key is first turned on. If you see swirling, then you likely have a u-hose failure. That would be my first check since it is an easy check and a common failure mode. If not that, then you are at the basics of checking for spark and fuel and both require some work on the LT.

I am not that familiar with the alarm and immobilized details as I disabled my immobilized right after getting the LT and I rarely use the alarm, but John Z will probably chime in with details there. I am not sure if an alarm fault still allows cranking or disables everything.
 

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Wrencher Extraordinaire
2005 K1200LT
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Nope, Matt nailed the #1 most often cause of sudden LT death, fuel pump hoses. The alarm will not even allow cranking.
 

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Not in Reverse is also a requirement. I park on a slope at work and put the bike into reverse to hold it on the slope as I use the EHCS.

With key-on, and after the self check, is the temperature light on?
From sailor - "If the RED engine coolant warning on dash is not ON , then the EFI system is offline and one of the items above is not OK (or the EFI system fuse is burned)"
 

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Haven't had a need to call out to the forum for a while with a problem, but might need some help with this one.

Rode the LT to get its annual registration check today, then home, then to the supermarket and parked in an underground parking area. All up no more than 10kms distance. Bike started fine each time.
Go to leave the supermarket carpark about 30 mins later, and the bike won't start... turns over OK, but refuses to fire. Check the stop switch isn't actuated... sidestand isn't down as its on the centrestand. It did this once to me a couple of months ago, in same underground carpark.... at that time I bumped it down the next ramp but it wouldn't start... but then it key-started OK.
So tried the same trick today, but no luck... will not fire up... tries to.. sometimes get a low rumbling like its almost running but won't kick into life. So left it and caught a bus home.

Keep the LT on trickle charger at home, but haven't been riding a lot and mainly short distances when I do.
Installed a new Motobatt AGM battery 12 months ago, voltage reads around 12.7. Filled with fresh fuel about a week or so ago.

Went back tonight after wife got home with car, took a spare "charged" battery and jumper leads.... same deal. Thought it was going to rumble into life a couple of times, had a couple of small backfire "bangs"... but still no dice. So tonight I've given up.

I'll take my little bike back down tomorrow with a laptop and GS911, and some tools, spare battery etc, see if I can figure out whats gone wrong, but would appreciate some tips on things to look for, besides the obvious like:
  • not in gear,
  • stop switch off (I rarely use it anyway)
  • sidestand not down (maybe I'll flick it up and down and make sure that switch isn't stuck?)
  • listen for fuel movement (although I've never been able to hear it before)

What aren't I thinking of... its almost like there's a kill switch activated......???? (There's no alarm on this bike)

And it's not in an easy spot to get hauled out of without the help of a couple of hefty mates (we've been in lockdown for a COVID breakout in Sydney for 48 days straight now, so that isn't happening anyway), certainly probably couldn't get it on a trailer down there... and van wont fit down there either... I get it moving or it ain't moving. :(

Any tips appreciated... I'll check in, in the morning. Cheers guys!
I had one with a bad solder connection to the pump in the tank. It had come loose completely.
After removing the pump a good solder job and back to normal.
 

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Discussion Starter · #6 · (Edited)
Thanks guys... Had forgotten the possible split fuel line scenario... will be heading down to check bike soon, so that'll be first thing!!!
cheers all!


-----------------------

Well, can't see any fuel swirling in there.... and can't get at the computer connector without taking sides off. It'll have to wait till I can find a way to get it out and home. What fun, couldn't have picked a much worse place to stop on me, except maybe outside in traffic if it was raining. :rolleyes::LOL:(y)
 

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Discussion Starter · #8 ·
Haha.... You don't know my bike! There's a big oil can for the rear shock in the way. 🙃
 

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Discussion Starter · #9 ·
Got the bike home with some hard grift and a huge helping hand from my next-door neighbour, who also owns an LT, and his cousin. Greek boys with big hearts. Had to hire an 8x5 trailer and use the neighbour’s car.
Plenty of time ahead to start digging into it…. we’ve been locked down even tighter for another week…. bloody Delta!
 

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Hope it’s not too serious.
Cheers.


Sent from my iPhone using Tapatalk Pro
 
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Discussion Starter · #11 · (Edited)
Tear down day....
For starters... here's what the bike is doing when I try to start it... note that I had started and ridden it several times in the hour immediately before it decided to not fire up.
Once or twice when I was doing this (trying to start it) it backfired a little...


Put the GS911 on the bike and did Autoscan... NO fault codes found.

So started to tear down the plastics to get to the fuel pump and check the hoses... can't see any issues with the hoses or pump visually, all looks OK, apart from the end of the little black nylon? bag (is that some sort of float bag?) has the very end slightly torn, although it doesn't seem to be split open (see pics).

Checked the spark plugs.... a little oily looking, probably from trying to start it numerous times with no luck. Since I had them out, I've put a new set in anyway.

Not sure where to look or test next?
One thing I did notice is up next to the throttle bodies there's a wheel with the cable around it... just wondering if it looks like this cable is out of place as it seems to run over the top of the wheel?
Might it be a cause of the non-start?

Further guidance required from the gurus.... :rolleyes: (y)









 

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Wrencher Extraordinaire
2005 K1200LT
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If that cable over the top was affecting the idle position it would show up with the 911 (DAHIK). It is not correct but that is the cruise control cable so it should routed correctly.

I would put the pump in a bowl of gas and run it to see if those hoses are leaking. If you have the metal QDs they will hold the pressure when disconnected. If that is ok the hook it back up and check fuel pressure.
 

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Discussion Starter · #13 ·
Thx John, thats my task for today then. Yes it has metal QDs.
Assume just 12v applied to the connection is fine to turn it over?
 

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2005 K1200LT
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Yup, Just make sure the polarity is correct or the pump will run backwards and not move fuel. (Negative to the Brown wire)
 
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Discussion Starter · #15 · (Edited)
edit: looking at fuel filter parts list I just noticed that black bag is a strainer... so no wonder fuel was leaking out from there... doh! May have to try this again tomorrow, sitting in fuel. :rolleyes::cautious:
___

Pulled the pump and put it into a small container, but not soaked in petrol (gas). Figured the pump would probably still be full so see if anything leaks out. Applied 12v (on correct +/- pins)... pump ran and I started getting a small amount of fuel leaking into the container. Pretty sure not from any of the the fuel lines, but from that little black bag, either the end of bag itself where the end is seamed but torn slightly, or where it is joined on to the pump unit. Hard to tell.
Anyway, I put the tank back on the bike and reconnected things, tried starting, no go and with the same symptoms as previously.
So I guess I assume there's an issue with the pump unit not feeding enough fuel to the injectors?...... so do I find a new one and install it, see what happens?
Or is there something else I should check before going down that path? Getting toward my mechanical limitations around this issue.
Did a final GS911 scan, and still no fault codes. Also did a GS911 "fuel test"... I could hear the pump running but I knew that worked already.
Thoughts?

ps...tried re-routing that cruise cable on the wheel, but it doesn't want to sit quite right, and I couldn't figure how to get the black box that surrounds the air intakes off to get at it properly. :(

 

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It could also be the pressure regulator on the fuel rail, only way to tell is to measure the fuel pressure.
 

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Not sure that was a good enough fuel pump test to know if it was working or not or if the filter was clogged or not at least by what you typed in as the test. It runs at 50PSI and can generate higher pressure if dead ended so it should flow a good amount of fuel in a short test. If all that is good, as John said, there is the pressure regulator to look at also.

Just watched your video. It sure dies look like low fuel pressure as it tried to catch.
 

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Discussion Starter · #18 ·
Yeah, realised I hadn't really tested it as per John's suggestion once I started looking at replacement parts list & pics.
I have no idea how to test fuel pressure... but I'll try to check the pump with pump submerged in fuel tomorrow (don't really like playing with petrol like that though).
Likely I'll order a new pump etc and see if that makes a difference... if not it'll have to be taken to a BMW dealer to work through. 😟
 

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Yeah, realised I hadn't really tested it as per John's suggestion once I started looking at replacement parts list & pics.
I have no idea how to test fuel pressure... but I'll try to check the pump with pump submerged in fuel tomorrow (don't really like playing with petrol like that though).
Likely I'll order a new pump etc and see if that makes a difference... if not it'll have to be taken to a BMW dealer to work through. 😟
Given the symptoms described in text AND in the Video, I would approach the problem this way:
It could be Fuel OR Ignition related, but history of potential issues on these K1200LT-RS , combined with fact it came suddenly, I always start by troubleshooting a fuel issue first.

By the way, unlike later frontal 4 cylinders models OR the R1200-R1250 series , the GS911 cannot help you much to check fueling issues as the K1200LT-RS system has a mechanical pressure regulator only (no electric regulator or pressure sensor data). The only place where the GS911 can help is after we have confirmed the steps below with pressure gauge. If needed, we can trace / log data for other sensors and the amount of fuel sent by Motronic (injector time). I have here many logs so as to compare normal baseline for a K1200LT.

I do not believe in buying replacement parts first (like a pump). I would rather buy an fairly inexpensive tool that will give me the data needed to confirm IF indeed I need to buy replacement parts. In this case a "fuel pressure testing kit" can later be reused for another project (car or motorcycle) AND has value to be sold used if not needed later. You might also be able to borrow such kit from a mechanic cheaply. For K1200LT-RS all you need is a spare set of fuel quick connector - plastic or metal types are compatible together if similar click tab design made by CPC.

WE WILL be CHECKING (directly or indirectly):
- the fuel pump is able to furnish proper pressure. In general if we measure acceptable pressure - we do not bother to check exact amount of flow of time although not very hard to do.

- one or several fuel injectors could be clogged OR stay stuck open

- the fuel pressure regulator (at end of fuel-rail): check to see if rail pressure is stable when running and after stopping.

Like any modern fuel injected 4 stroke engine (car or motorcycle), engine will not start of function properly if the whole fuel system (pump , fuel-rail, hoses, injectors) cannot maintain a constant pressure at or slightly above specs. In this case the specs are 51 PSI (+ 10 % is OK).

STEPS:
1) Install pressure gauge as shown: in line with "pressure side" hose outlet - this is the outlet below pump most inboard toward frame. See photo below.

2) Turn ignition ON and wait about 8 seconds for the short pump priming to finish. You should see needle jump pretty fast between 45 and 55 PSI. Wait 15 seconds to see if it stays fairly stable after priming phase.

3) Attempt to start and run it for at least a few seconds (2 minutes if you can). When engine is running the pump is working almost full time and should show a CONSTANT value between 50 and 54 PSI. Stop the engine - ignition OFF.

4) In addition to above, the system must be able to maintain a certain pressure at least 10 minutes AFTER you stop the engine. Ten minutes after the engine has stopped, you should not see less than 44 PSI - otherwise there is a pressure leak either: (A) inside tank at short hoses or at pump, (B) at fuel pressure regulator , (C) one or more injectors is not closing completely. If we detect a problem, this would require further tests....

P.S.: On Amazon for Australia, I found a kit that is almost identical to the one I bought many years ago here in Canada. There are many variations of these "fuel pressure tester" kit - some are more universal than others so as to be used on various car EFI systems.


174780
 

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...
One thing I did notice is up next to the throttle bodies there's a wheel with the cable around it... just wondering if it looks like this cable is out of place as it seems to run over the top of the wheel?
Might it be a cause of the non-start?
.....
As the other John posted (JZEILER), this cable on the most forward pulley of throttle-bodies is for the Cruise-control mechanical unit. Although this could affect the throttle NOT being at proper idle stop (when closed) , thus confusing the TPS data by pulling a bit on throttle mechanism, given the video symptoms, I doubt very much this is the case.

You would need to remove a lot of stuff including airbox to get full access so as to reinstall this cable properly.

HOWEVER, if the fuel pressure testing shows all is well on that side, you may check the proper TPS setting using GS911 without having to do much removal of parts (except TVA - idle actuator unit).
 
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