Author Topic: Engine dies on the run. Wait a few minutes, and it runs again. Likely suspects?  (Read 21264 times)

Offline BlitzenGruv

  • ^ Proficient Motobricker
  • Posts: 218
  • My first BMW. Been riding old British forever..
My check of codes reveals 1133, bottom HES. Though the engine is running on all four cylinders.
Q1: Will cleaning the connectors solve this?
Q2: Does it take two 'cycles' of driving to clear the codes, as with OBD on a car?

I don't wish to ride with the chance of being stranded again.
  • Crossville, TN
  • '92 K100rs, 16v, '71 BSA Lightning, '72 Triumph Bonneville, '72 Triumph Trident
You say I'm schizophrenic, but I don't believe we are.

Offline Al

  • ^ Motobrick Curious
  • Posts: 97
Blitz, that's funny because I had on 1976 Bonneville years ago. IT had been rode hard and put away wet when I got it. But I had no problems with the switches. Other Lucas devices gave grief- like the headlight needing a tap in  the middle of the night to turn back on. Maybe I was just lucky.


I would have thought for what BMW was charging for these bikes back in the day that they would have been little more robust and sealed from the weather. Heck, they may have even put in a headlight relay.
  • Manitoba
  • K75RT
Four wheels move the body. Two wheels move the soul.

Offline bizzaro

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  • co pilot
BlitzenGruv,
Thanks. I have pretty much worked through the likely suspects, and things people have brought to my attention.  As I don't have a fault code tester I used the warm bike/hair dryer on the exposed HES method to check the HES.  Made sure it it got damn hot. The the motor idled like a champ and revved great till I shut her down after 10 to 15 minutes of pouring on the heat to the HES with the cover off on a warm engine.  Where did you get your fault code tester/analyzer.  I am growing tired of throwing darts.  A fault code reader would go a long way toward narrowing down my issues, now and in the future.  I definitely have the Brick Disease! :yow :hehehe I JUST CAN'T STOP!!!

I have cleaned up all my connections including the Motronic, and the kill switch.  I didn't take apart my ignition yet, though I did spray it with electrical cleaner. (I don't think that is the problem). I am pretty sure something is causing he fuel pump to cut out occasionally. Relay is fine....I switched it out for the horn/fan relay.  I am thinking it could be the pump is dying (do/can fuel pumps run intermittent when they go?), the motronic is maybe faulty, or there is a short I can't pin down.

In my wrenching I did find some stuff the P O had done that needed to be addressed.   :nono
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline wally.fisher

  • ^ Motobrick Curious
  • Posts: 94
BlitzenGruv,
Thanks. I have pretty much worked through the likely suspects, and things people have brought to my attention.  As I don't have a fault code tester I used the warm bike/hair dryer on the exposed HES method to check the HES.  Made sure it it got damn hot. The the motor idled like a champ and revved great till I shut her down after 10 to 15 minutes of pouring on the heat to the HES with the cover off on a warm engine.  Where did you get your fault code tester/analyzer.  I am growing tired of throwing darts.  A fault code reader would go a long way toward narrowing down my issues, now and in the future.  I definitely have the Brick Disease! :yow :hehehe I JUST CAN'T STOP!!!

I have cleaned up all my connections including the Motronic, and the kill switch.  I didn't take apart my ignition yet, though I did spray it with electrical cleaner. (I don't think that is the problem). I am pretty sure something is causing he fuel pump to cut out occasionally. Relay is fine....I switched it out for the horn/fan relay.  I am thinking it could be the pump is dying (do/can fuel pumps run intermittent when they go?), the motronic is faulty, or there is a short I can't pin down.

In my wrenching I did find some stuff the P O had done that needed to be addressed.   :nono

My bike started cutting out intermittently after cleaning the connectors, grounds and all I could find it continued, last resort I stripped out the ignition, problem solved.
The contacts. Are enclosed in a plastic housing mounted at the bottom of the switch, no amount of electrical cleaner will enter this housing, it must be removed to clean the contacts.


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Offline bizzaro

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But my starter engages when it shuts down, and it sorta coughs and sputters a bit. Wouldn't an ignition failure at the key shut everything down? The starter, lights, and all?? Like dead?
  The last time it "shut down", it usually just stuters on the run and kicks back in, The fuel pump was definitely not coming on. Even when I wigged the key around in the ignition.(And the four pin connection and wires to the fuel pump).

I guess the ignition has to be done sooner than later.  Damn. I still have the theft proof bolts that I will have to drill out.  PITA.  :dunno2:
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4475


You can just use a test light and count the pulses.
Regards Martin.
Motronic Fault Codes ~ author frank warner- BMW ...
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline bizzaro

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Thanks Martin.  Damn, the right side of the pages in the PDF are chopped off. 
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4475

Seek and ye shall find, it's available elsewhere. :dunno
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline bizzaro

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  • Posts: 583
  • co pilot
yea, been trying google searches etc. It'll turn up. Thanks again.  Got it off his website.....
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline Laitch

  • Faster than a speeding pullet
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Thanks Martin.  Damn, the right side of the pages in the PDF are chopped off.
Coming in good on my Mac, biz. Maybe it's how your pages are laid out.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline bizzaro

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  • Posts: 583
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HMM. Maybe if I print it, I will get the whole page.  It is probably the new and wonderful Windows 10. (NOT)  One day I will afford a MAC!. (though I thought a PDF is what it is?)

 Hey, I saw one of those oversized scooters, a P C go by my house the other day.  Blew my mind.  I have never, ever seen one, cept for the photo you put up here!  I was like.............what the hell is that.....................holy shit its that ugly freakin bike Laitch posted! :mbird Is that a Honda?
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline Laitch

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HMM. Maybe if I print it, I will get the whole page.  It is probably the new and wonderful Windows 10. (NOT)  One day I will afford a MAC!. (though I thought a PDF is what it is?) . . . holy shit its that ugly freakin bike Laitch posted! :mbird Is that a Honda?
A PDF is what it is—as many a thing also is.

Anyway, the PC is my dream bike. :Rabia: It has the perfect initials for Vermont.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline White Dog

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  • Posts: 230
Has anyone mentioned testing the coils?  I had a car once with a bad coil and when it got hot, it quit.
  • Basement Garage
  • '95 K75 ABS.
'95 K75 ABS Red
'96 R1100RT Burnt Orange
2008 Goldwing Black
2014 CB1100 Std. Black
Reside in NC

Offline Laitch

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The the motor idled like a champ and revved great till I shut her down after 10 to 15 minutes of pouring on the heat to the HES with the cover off on a warm engine.  Where did you get your fault code tester/analyzer. 
Has anyone mentioned testing the coils?  I had a car once with a bad coil and when it got hot, it quit.
There is a description of an HES test using a 12V LED and also a description of a test for coil function—as White Dog mentioned as a possible fault—if you scroll down through this document. Don't rule out either until you've done these tests, or until the bike starts up and runs well for some random reason. :giggles
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline bizzaro

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Ah yes the coils.................I still believe it is fuel related, but I need to check all possibilities................... Are coils on the K prone to failure?
Thanks for the link Laitch. I am running the K11 4 valve if that makes a difference?  Off to work now.  I probably won't be able to poke around till Friday.............................. :eek: Damn.  I will post the resolution...................or frustration............................whichever comes first! :2thumbup:

Really Liatch, the PC 800? I thought you had taste!? :mbird And seriously. I didn't even know they existed till your post. Then out of the blue one drives by!  What is the message there? 
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline Laitch

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I didn't even know they existed till your post. Then out of the blue one drives by!  What is the message there?
You must hunt down the owner and offer him your K1100 in trade.

You're right about the troubleshooting guide, biz, it has limited application with your bike.  Still, all points of failure—coils included—must be investigated in sequence while you wait for that PC to return.  :hehehe
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline gone_ape

  • ^ Proficient Motobricker
  • Posts: 135
  • 94 K75RT (Now Standard)
You can see from this pic of a part of the previously uncleaned ignition switch it's nasty......and that's just half of it!!!

  • Austin, TX
  • 94 K75RT (Now Standard)

Offline gone_ape

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  • Posts: 135
  • 94 K75RT (Now Standard)
To aid in removal, only because for some reason my tabs on the housing were brittle and broke off when trying to remove it from the dashpad on my k75rt.......Note the orientation and arrangement of the two locking tabs...once you get the top cap off the switch (there are write ups how to disassemble) look down into the pad to see the slots you can use to insert a pick to disengage the tabs....oh wait you have a k1100...doggone it... the switch is the same, but mounting must be different....pic anyway....
  • Austin, TX
  • 94 K75RT (Now Standard)

Offline gone_ape

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  • Posts: 135
  • 94 K75RT (Now Standard)
One more and I'm done...IF YOU CHOOSE to go down the switch disassembly path....realize these few things:  The white plastic parts inside are brittle....brittle...did I mention they are brittle????  And probably most important...the little set screw holding it all together was installed by Hans with a 3/4 inch drive impact driver ....J/K but that little screw has a dab of paint on it to keep it from backing out and I believe its brass...VERY SOFT....BE CAREFUL or you'll round the slot in the screw and then you're in trouble.......carefully remove the paint and heat it up with a hairdryer to soften things abit...the screw is a PITA to remove!!!!


Second photo shows the length of that set screw and the third shows the (broken) whit plastic brittle brittle tab which the set screw locks into....
  • Austin, TX
  • 94 K75RT (Now Standard)

Offline bizzaro

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Wow. Thanks for all that. The warnings and cautions much appreciated. :2thumbup:
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline White Dog

  • ^ Proficient Motobricker
  • Posts: 230
Gone_Ape,
How do you plan to put the switch back together with the broken white pieces?  As clumsy as I am, I would probably just buy a new switch if I had to, rather than break plastic.  I've never found a glue strong enough to hold plastics back together.
  • Basement Garage
  • '95 K75 ABS.
'95 K75 ABS Red
'96 R1100RT Burnt Orange
2008 Goldwing Black
2014 CB1100 Std. Black
Reside in NC

Offline bizzaro

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  • co pilot
Yes, got a link for ignition cleaning some posts back compliments of Laitch and several folks have endorsed the ignition cleaning. But thanks for your contribution and cautions.


My plan, when I get there, is to smoke a giant bowl of pensive weed, be extra gentle, and not break the switch thanks to gone_ape's warnings! :2thumbup: And if I do, I will find a way to repair or modify it. There is ALWAYS a way.  I am sure BMW has a replacement ignition for $500 or so bucks............. :eek: Not going that route. I would replace it with a toggle first! :hehehe
  • Vermont
  • Current:1994 BMW K1100LT Previous: 1982 Yamaha virago 920,1973 Honda CB550,1976 Yamaha 650 Special
See Ya in the Twisties,
 Bizz

Offline Laitch

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One more and I'm done...IF YOU CHOOSE to go down the switch disassembly path....realize these few things:  . . .
Excellent cautionary post, gone_ape.  :clap:

Here are some supplemental instructions, biz, in case you don't have them yet.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline gone_ape

  • ^ Proficient Motobricker
  • Posts: 135
  • 94 K75RT (Now Standard)
W Dog....i bought another switch from a IBMWR advert.  I as well could not re-glue the plastic bits, which is a bummer... That broken tab can be worked around as you possibly could epoxy the two halves together,
[size=78%]but then future re-cleaning would be nullified....[/size]

Just food for thought....Wanting to use my original key....The used switch I bought was so gummed up I was able to use my original key to disassemble the lock as the tumblers would stick open so it would come apart!!  you do not need a key to clean the switch BTW....
Long story short, I got lucky and was able to swap my lock into the newly purchased assy... you may be able to as well.  And being curious, After cleaning the "new" lock tumblers, they returned to their original function and my key no longer worked.....
  • Austin, TX
  • 94 K75RT (Now Standard)

Offline White Dog

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  • Posts: 230
So which key and tumbler will you be using?  You know you can swap tumblers around if need be or file them flat with the cylinder as long as you have a key in the cylinder.


I don't have any problems with my ignition switch, but knowing it is on the list of things likely to fail ...
  • Basement Garage
  • '95 K75 ABS.
'95 K75 ABS Red
'96 R1100RT Burnt Orange
2008 Goldwing Black
2014 CB1100 Std. Black
Reside in NC

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