BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down   Ignition Problems Empty Ignition Problems Fri Apr 29, 2011 12:04 pm

Gardell

avatar
active member
active member
85 k100RT 102,000 mi, Very rough running when started, I kept it running while I pulled off plug caps 1 and 4, there was no change in engine. Plugs were wet, with new plugs I get weak or often no spark. Number 1 plug wire measures 3.5 k ohms and the others are 5.5-5.7 k ohm.

No signs of any external arcing when running at night. The coils are both open (> 2 meg ohms) between the high volt sides.
I have seen on this site where this should be 12.6 k ohm, I wonder why it runs at all. Also they are open between the high volt and ground, is this normal?
Do I need new coils and wire(s) or is the problem somewhere else?

New Hall sensor a few years back but I will try checking it with a LED when I get home.

Nice weather today, getting desperate, I am about ready to leave out 2 plugs and take it for a ride anyway.

    

2Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri Apr 29, 2011 1:39 pm

japuentes

japuentes
Life time member
Life time member
Hi there,I had the same problem by december. Looks like the coil serving cil 1 4 aint working, if the engine is running and both coils measure the same, guess failure is due to dirty contacts. Clean all the low and hi conections, hig ones may need some fine grinding paste to clean de cup inside, dirty primaries are also known to cause this failure. Hope this helps
Best regards
JAP

    

3Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri Apr 29, 2011 2:58 pm

ReneZ

ReneZ
Life time member
Life time member
Change the coils around and see if the problem shifts with it, then you have your answer.


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Ignition Problems Rain
BMW K1200GT - 2003 (ZK01223)
    

4Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri Apr 29, 2011 4:01 pm

Gardell

avatar
active member
active member
I did clean all the low voltage leads on the coil (several times) the high voltage looks shiney and clean. I also swapped wires several times and sometimes get spark and sometimes not so something seems intermittent. I will have to try again this evening. I think I will pull all the plugs, short them all with some bare copper wire to a good ground and then try switching the neg low volt wires.
I always seem to have constant 12V to the + side but do not know how to see if the neg side is pulsing as it cranks over.
The spark always seems thin and yellow, not the fat blue spark I am used to on other older antique engines around the farm, but the dealer said this is "normal" for BMWs with electronic ignition?

    

5Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri Apr 29, 2011 6:22 pm

ReneZ

ReneZ
Life time member
Life time member
Not so - you should get a good fat blue spark!


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Ignition Problems Rain
BMW K1200GT - 2003 (ZK01223)
    

6Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri Apr 29, 2011 6:46 pm

charlie99

charlie99
VIP
VIP
hi gardell ....
yes it is correct that the primary and the secondary are not connected at all .
and yes it has been confirmed that good coils secondary measures in the region of 12 k between the outputs
did you use paper clips to probe the high tension stack/terminals ?

its important that both plugs be fitted and be good when looking at this test .
because the output of the high tension is double ended ....meaning that when the spark initiates it needs to have the same gap to earth at both ends .
it seems a wierd setup to me, but thats the way its designed and nowhere near a strange setup in motor bikes at all.

if you were to only look for 1 of the plugs spark ....(leaving the other plug off or fouled ) might contribute to not seeing spark at all .

? could it be time to change the plugs anyhow ?


it would be highly adviseable to open up under the tank and clean up the ignition computer (ignitor) terminals /connections and the under seat computer connections with deoxit .

whilst under the tank clean the earth points on the frame nearby and confirm that the main earth (just near the batery ) is also clean and not corroded .
i beleive that the negative of the pair feeding the ignition coils is the "switched " side of this circuit , so it would be important that all these paths have a good ability to switch high currents without losses.

hope this helps

    

7Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sat Apr 30, 2011 8:15 am

Gardell

avatar
active member
active member
Thanks for added info on how the ignition works, it now makes more sence some of the inconsistency I was seeing the other day. I will check with new BMW plugs (10$ each). I am also planning on pulling the tank off and cleaning everything with deoxit, I found it for sale at a local radio shack.
My multimeter has a long and narrow enough tip to probe to the bottom of the primary sockets on the coils and no sign of corrosion in there, it still measures open, so I am thinking of getting some used coils.

    

8Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sat Apr 30, 2011 8:27 am

charlie99

charlie99
VIP
VIP
good idea mate ...i think og replaced his recently ....with good results

dontcha wish you could get inside and fix the the problem ?

there is a spark plugs thread currently running gardall ....ngk plugs have a positive result .... and dont cost the earth ..d8ea or d7ea for the standard ones ...dont forget to ask for the ferules if not fitted


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OIgnition Problems Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

9Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sat Apr 30, 2011 8:56 am

Gardell

avatar
active member
active member
I saw the info on plugs, bought the NGK (about 2.50$ at autozone) but they did not have and did not know where I could get the ferules, I could only find 2 in the junk bin here so I picked up the official BMW plugs on the way home. I may make a few of the ferules on the lathe.

    

10Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sat Apr 30, 2011 9:06 am

Guest

avatar
Guest
Ferrules? Every spark plug known to modern man has one screwed to the end of it if it is removable, same thread, same diametre, all of them. Kids. They hire kids to staff the shops and unless they grew up with it or someone took the time to be patient with them they often don't know a bloody thing. Get a ferrule from a pile of used sparkies down the junkyard. I have twenty in the corner of one of my tool boxes.

    

11Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sat Apr 30, 2011 10:37 am

Gardell

avatar
active member
active member
So I put the new plugs in the wires (with all other wires connected) and measured between the plug inner posts they are open between #1 and 4 they are open between plugs 2 and 3, supporting what I measured the other day that coils are both open.

Next I connected the threaded area of each plug to each other and to ground (12 ga solid copper wire) and cranked her over. First I see a nice bright spark on all 4 cylinders Very Happy . After several seconds cylinder 1 starts missing and after about 10 seconds cranking there is no spark on cyl 1 or 4. Numbers 2 and 3 still look good.

Actually it seems you only need to connect the threaded part of plugs 2 and 3 togather to get a nice spark, they do not need to be connected to engine ground. Makes sence from what charlie99 posted.

I switched the low voltage wires and get same thing. Switching high voltage leads and I still get no spark from the one coil. Sure seems like one bad coil, a little strange both coils read open between the high voltage sides.
I am going to go ahead and clean everything under the tank while I try to source some new or used coils.

    

12Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sun May 01, 2011 7:57 am

ReneZ

ReneZ
Life time member
Life time member
You do have your multimeter at the right setting don't you?? Don't ask why I'm asking Embarassed


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Ignition Problems Rain
BMW K1200GT - 2003 (ZK01223)
    

13Back to top Go down   Ignition Problems Empty Re: Ignition Problems Sun May 01, 2011 1:23 pm

Gardell

avatar
active member
active member
Yes I have checked coil output resistance multiple times, I was a little worried that it is only a 15$ multimeter so I checked it with another. I cleaned all the connectors under the tank and same thing, good spark for 5 or 10 seconds.
Question on checking the hall sensor with a LED, can this be done by just cranking the engine and looking for the LED to go on and off or do I need to remove the sensor and put something metalic in the gap? I have checked most of the other voltages and resistances on the ignition and injection computers. Guess I have to just wait for parts now, I should go cut some firewood anyway.

    

14Back to top Go down   Ignition Problems Empty Re: Ignition Problems Wed May 04, 2011 5:32 pm

ReneZ

ReneZ
Life time member
Life time member
There is a bit of info somewhere to build a simple tester where you test the signal from the sensor. Not to difficult. However, if your plugs keep on sparking the Hall sensor is OK as that one triggers it. If the spark is there, but changes, then the park producing parts are suspect; could be the injection module, the coils, the plug wires or the plugs themselves or the wiring between the module and the coils.


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Ignition Problems Rain
BMW K1200GT - 2003 (ZK01223)
    

15Back to top Go down   Ignition Problems Empty Re: Ignition Problems Thu May 05, 2011 8:13 am

Gardell

avatar
active member
active member
I got the new (used) coils and wires in the mail yesterday, the coils measure 10 k ohm across the high tension side. By mixing old and new I found 4 wires around 5.4 k ohm. Getting a very nice and stable blue spark on all cylinders (it was thinner and white befor). I am pretty sure the problem is solved but still need to reassemble everything. Thanks guys, What an excellent fouum.

At this point I am not sure I am going to test the hall sensor because I cannot find a connector that will allow me to hook up the diode tester without the risk of shorting something out.

    

16Back to top Go down   Ignition Problems Empty Re: Ignition Problems Thu May 05, 2011 10:23 am

charlie99

charlie99
VIP
VIP
give it time gardell .....you will find a reason and the enchouragement , and advice if you need it......... from your new friends .

good result on the spark mate .......i hope that this is a turning point for you and the k .......slap it together and go for a ride mate ...sometimes ...just the thrill of acheiving a repair, can put all things in a different spotlight ,,,,,enjoy brother !!!!

    

17Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri May 27, 2011 4:47 am

K-BIKE

avatar
Life time member
Life time member
Well done Gardell.
Regards,
K-BIKE

    

18Back to top Go down   Ignition Problems Empty Re: Ignition Problems Fri May 27, 2011 8:10 am

Gardell

avatar
active member
active member
Thanks again everyone for the help, Bike is running great with the new (used) coils and wires. It feels great to have the information available to troubleshoot this myself instead of dropping another 1000$ at the dealer. Sometimes it is hard to believe I have had this bike for 26 years and 103000 miles.

    

19Back to top Go down   Ignition Problems Empty Re: Ignition Problems Wed Jun 01, 2011 3:28 pm

Adiwan Djohanli

Adiwan Djohanli
Silver member
Silver member
Ignition Problems 502531 Ignition Problems 212902


__________________________________________________
Adiwan Djohanli
Jakarta-Indonesia[i]
    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum