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1Back to top Go down   Troubleshooting guidance requested Empty Troubleshooting guidance requested Mon Apr 23, 2012 1:52 pm

C_Mick

C_Mick
Silver member
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Re. refurbishment of (1986) K75S

Having received a new Motobatt AGM battery today I fitted it and checked what does and doesn't work.

Troubleshooting guidance requested K75S_battery

Works
Indicators and switch that cancels their operation
Parking lights
Brake lights (front and rear brake operation)
Main headlight beam "flash" switch
Kill switch
Starter motor button and motor itself (engine turns over)
Horn
Instrument panel lights (all seem to be working)

Doesn't work
Engine turns over but wont fire up
Headlight main beam and dipped beam

Relevant background
Bike had stood unused for 5+ years without any recommended laying-up procedures being observed and with a full tank of fuel. In the past few weeks I have carried out most of the specified service operations and cleaned up the main earth contact points on the frame and some of the circuits' connectors.

Way forward?
For the main concern, 'engine turns over on the starter, but will not fire up' my next step will be to check whether a spark is delivered at the plugs, and if not, follow up with other checks of the ignition system.
I would appreciate some advice on how to proceed if the plugs are delivering sparks but the engine still will not start.

Overall I am feeling very positive about how much of the bike's electrics is working in spite of years of neglect.

Regards, Chris



Last edited by C_Mick on Tue Apr 24, 2012 2:39 am; edited 2 times in total


__________________________________________________
Two wheels good...Four wheels bad...
    

nino

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Chris, if engine wont fire I reccomend first to check fuel pump. When hiting a start button you must hear whining sound of pump. If you hear, but engine wont start its probably clogged fuel filter. After 5 years siting you have to put new one.


Can check the spark but I dont believe thats cause. You probably put new spark plugs

Regards

    

nino

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nino wrote:Chris, if engine wont fire I reccomend first to check fuel pump. When hiting a start button you must hear whining sound of pump. If you hear, but engine wont start its probably clogged fuel filter. After 5 years siting you have to put new one.


Can check the spark but I dont believe thats cause. You probably put new spark plugs

Regards



You can check fuel if remove hose from rail (lower end) and hit the start (not with cigarete in another hand). If fuel goes out, could be electrical

    

Inge K.

Inge K.
VIP
VIP
C_Mick wrote:Doesn't work
Engine turns over but wont fire up
Have you seen the troubleshooting guide at the portal?

You might have wet fouled spark plugs after many starting attempts,
then it won`t start whatever you do, before you have dried them.

BTW. How does the spark plugs look like...colour...wet...dry...


C_Mick wrote:Doesn't work
Headlight main beam and dipped beam
Since your high beam flash signal functioning, the problem would be limited to RH or LH switch assy and both its connectors under the tank.

LH switch assy is the most common source for malfunctions.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

C_Mick

C_Mick
Silver member
Silver member
Thanks for your helpful replies guys and your tip Inge on the chief suspect regarding the faulty dipped and main beam lights; I've just looked at the Troubleshooting Guide and it will be incredibly useful. I'll post some info about how I get on.
Later, Chris


__________________________________________________
Two wheels good...Four wheels bad...
    

C_Mick

C_Mick
Silver member
Silver member
C_Mick wrote:Re. refurbishment of (1986) K75S

Works
Indicators and switch that cancels their operation
Parking lights
Brake lights (front and rear brake operation)
Main headlight beam "flash" switch
Kill switch
Starter motor button and motor itself (engine turns over)
Horn
Instrument panel lights (all seem to be working)
Digital clock

Doesn't work
Engine turns over but wont fire up
Headlight main beam and dipped beam

Relevant background
Bike had stood unused for 5+ years without any recommended laying-up procedures being observed and with a full tank of fuel. In the past few weeks I have carried out most of the specified service operations and cleaned up the main earth contact points on the frame and some of the circuits' connectors.

Regards, Chris

I've been busy this morning, so time for an update: having dismantled the handlebar switches and cleaned electrical contacts I got the headlight main and dipped beams to work OK. Success! Regarding the engine not firing up, I checked the functioning of the fuel pump. I could hear it whirring for a short while after I pressed and released the starter button. Then I pulled plug #3 and checked for a spark when I operated the starter. There was one. But to make absolutely certain I replaced all 3 with new Bosch plugs I had in stock. I examined the pulled plugs and on 2 of them the ceramic core and electrode looked to be dry. (I had previously dried the plugs out over a gas ring.) So I can add to my list:

Works
Fuel pump
Coils HT leads and spark plugs (spark delivered)
Headlight main beam and dipped beam

Doesn't work
Looks like fuel is not being delivered to 2 cylinders (going by 'dry' appearance of spark plugs).

Would I be correct in thinking that I should remove the fuel rail and injectors and get them serviced - or am I jumping the gun? Replies appreciated.

Chris



Last edited by C_Mick on Thu Apr 26, 2012 11:58 am; edited 2 times in total


__________________________________________________
Two wheels good...Four wheels bad...
    

Inge K.

Inge K.
VIP
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Since you now got your headlight functioning, I would advice you to install headlight relays, to avoid future problems.

About injectors: use a screwdriver as a stethoscope, and listen if they make a clicking sound when turning the starter.

If they do, they`re probably clogged.

If not, measure injector coils and connectors (should have 12V+ when turning the starter, same feed as fuel pump), opening signal is pulsed ground.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

charlie99

charlie99
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chris ...just a heads up ,,,there are filters built into the top of the injectors ,,,could some gunk have passed the main fuel tank filter and blocked them ?

another thought is to check the ignition coils ,,,we have found that the primary of the coils is about 2.4 ohms and the secondary of the coils is about 10,000 ohms (direct to the output of the ignition coils)

reasonably sure of this as most of us have k100 s which use double ended coils not single ended coils as the k75 .

also check the high tension leads ,,they are known to become faulty ,,,i seem to recall that about 5000=10,000 ohms per meter is a pretty common reading . so a lead of about 45cm should be about 2500 - 5000-ohms or there about plug top to coil connector

i mention this as you say one is wet ...and the others dry ...could the wet one,... not be firing ?

hope that helps


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

9Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Tue Apr 24, 2012 11:03 am

nino

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Chris, did you change the fuel filter. If it is clogged engine would not start for shure. Did you check if fuel come to rail? Before remove rail with injectors, check the electric contact on injectors, clean it and spray with something like wd 40. Usually injectors are bulletproof, my advice is to check everything around before removing them.

Clogged filter stoped me in the middle of 6 km tunnel.

Regards

    

10Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Tue Apr 24, 2012 8:07 pm

CanberraDave

CanberraDave
Gold member
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After sitting for around 1o years I replaced the fuel pump and all the mounting hardware in the tank. Old one was perished from old fuel. On my first attempt to start I had fuel at the fuel rail and spark at the spark plugs. Only thing in between was injectors. Removed them and had them in an injector cleaner for three days. They could not be revived. A mate put larger injectors in his K and gave me his old ones. Put them in, hit the button and she fired on the second turn over. If you can't get your injectors to work and can't find a second hand set, you can get new ones from here at a reasonable price - http://www.euromotoelectrics.com/BMW-K-Parts-s/60.htm

I think the problem with mine was that some of the perished rubber from the fuel pump mount got into the injectors where it sat for some time and made them un recoverable.

Hope this helps and best of luck.


__________________________________________________
Canberra Dave
00 R1100RT
6/89 K100RT (RIP)
VIN # 0097704

What happens if you get scared half to death twice?

    

11Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Tue Apr 24, 2012 11:50 pm

club_c

club_c
Life time member
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Mick, I'm also on the injector bandwagon. I've refurbed two K100's, both had clogged injectors. Quickest way to find out is pull the injector rail with the injectors attached. Have a fire extinguisher handy. Touch the starter button a time or two. If no fuel spurts out, injectors are clogged. In both cases they were trash. The chemicals in the old gas seals them shut forever. I used refurbed Ford ones on the one bike, and a used set on the second one, good success on both accounts.


__________________________________________________
"There's never enough time to do it right, but there's always time to do it over."

1988 K100RS SE VIN 01477554
    

12Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Wed Apr 25, 2012 2:55 am

C_Mick

C_Mick
Silver member
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Thanks for the informative replies guys - you have given me some useful leads to follow and more reasons for spending more time in the garage. I have a very basic understanding of auto electrics and I'm on a steep learning curve to find out more. I'll post later with details of how I get on.

Regards, Chris


__________________________________________________
Two wheels good...Four wheels bad...
    

13Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Thu Apr 26, 2012 10:13 am

C_Mick

C_Mick
Silver member
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This afternoon I resumed work on the problem 'engine turns over on the starter but won't fire up'. I wanted to eliminate a blocked fuel filter as a possible cause of the engine not starting. So I disconnected the short rubber hose on the delivery side of the filter, pressed the starter button and watched as a stream of fuel flowed out. Then I removed the filter completely to compare the flow without a filter attached - there appeared to be no difference. So it looks like fuel under pressure is being delivered to the fuel rail and is being recycled back to the tank. From the appearance of the plugs when they were pulled a couple of days ago (2 appeared dry, 1 was wet) it looks to me that 'faulty fuel injectors' is a likely cause.

So I can add to my list:

Works
Fuel is being delivered under pressure to the fuel rail and recycled back to tank.
(Fuel filter is not blocked.)

I followed Inge's suggestion: holding a screwdriver against the injector bodies, using it as a stethoscope and listening for a clicking sound while the engine turned over on the starter. I wasn't sure whether I heard 'clicking' but maybe my ear isn't properly attuned (my wife says I'm going deaf anyway).

I decided I would follow the advice of 'club_c':

" Quickest way to find out is pull the injector rail with the injectors
attached. Have a fire extinguisher handy. Touch the starter button a
time or two. If no fuel spurts out, injectors are clogged..."

I applied reasonable force in trying to pull the rail and injectors bu abandoned the attempt as I was concerned about the possibility of damage to parts. So I decided to remove the rail completely, then remove the injectors.

Where I'm at now:

I was unable to detach the fuel lines from the fuel rail - they are 'stuck' in place
Instead I disconnected the fuel delivery line at the tank (and then removed the tank)
Removed the 2 bolts securing the fuel rail
Removed metal clips securing fuel rail to injectors
Tried to ease fuel rail from tops of injectors - but without success
Couldn't see how to remove the metal clips securing the electrical connectors to the injectors.

Specific advice / info needed:

How to detach fuel rail from tops of injectors
How to remove metal clips from electrical connectors on injectors

Thanks in advance, Chris


__________________________________________________
Two wheels good...Four wheels bad...
    

14Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Thu Apr 26, 2012 7:37 pm

Rick G

Rick G
admin
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How to get the injectors out and fuel rail of. It can be difficultwhen they have never been disturbed but just keep working at it and a bit of carb cleaner or degreaser down next to them may loosen the bond. It tool Charlie almost an hour to get all 4 out at the workshop weekend. Of course we all gave him heaps...................of moral support that is and kept him well supplied with beer.
Don't be affraid to be a bit heavy handed they like it rough these Ks.
And you need to speak french or german to them sternly


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

15Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Thu Apr 26, 2012 8:35 pm

Inge K.

Inge K.
VIP
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C_Mick wrote:Specific advice / info needed:

How to detach fuel rail from tops of injectors

As you have removed the metal clips, it`s only the tension from the O-rings that keeps the injectors in place (at both ends).
And as Rick says they can really tight, if they haven`t been disturbed since the last part of the alu age.


C_Mick wrote:How to remove metal clips from electrical connectors on injectors

Use a needle pointed instrument to pick them out of the recessed groove.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

16Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Thu Apr 26, 2012 9:33 pm

C_Mick

C_Mick
Silver member
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Thanks fellas, that gives me the knowledge to complete the next 2 steps. The injectors haven't been removed since the bike left the BMW factory. It seems I have been too gentle with "Heidi" so far.
Regards, Chris

@ Inge: I'm not clear how to go about testing / measuring the electrics relating to the injectors. I have a multimeter but my knowledge of electrics is basic.


__________________________________________________
Two wheels good...Four wheels bad...
    

17Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Thu Apr 26, 2012 10:43 pm

charlie99

charlie99
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in the "how to" section is a great introduction to multimeters ....by k-bike ....a well writen piece ...have a search for it



http://k100rt.aforumfree.com/t725-using-a-test-meter-volts-amps-and-ohms


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

18Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 12:27 am

club_c

club_c
Life time member
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Take a look at this lengthy thread. I had blocked injectors but it took a while to confirm that.

Blocked injectors testing


__________________________________________________
"There's never enough time to do it right, but there's always time to do it over."

1988 K100RS SE VIN 01477554
    

19Back to top Go down   Troubleshooting guidance requested Empty fuel injectors Fri Apr 27, 2012 1:53 am

lesso

lesso
active member
active member
i run my bike with idle switch unplugged if connected bike wont start . could this be the case.

i,m a complete novice but that was the problem i had

    

20Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 2:56 am

charlie99

charlie99
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idle switch? where exactly is that switch that you are talking about ? sorry ...i just cant visualise it ....maybe its an expresion -discription thing ...but willing to help if i can .


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

21Back to top Go down   Troubleshooting guidance requested Empty idle switch Fri Apr 27, 2012 3:13 am

lesso

lesso
active member
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look at left side of bike from the unit under the seat follow the leads to the butterfly switch. which is located on the back of the the injecters. one lead then goes under the seat. just unplug and see if it starts. . it,s in haynes manual in 6.3 chapter hope that helps

    

22Back to top Go down   Troubleshooting guidance requested Empty butterfly switch Fri Apr 27, 2012 3:20 am

lesso

lesso
active member
active member
sorry the proper name is butterfly switch

    

23Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 3:26 am

charlie99

charlie99
VIP
VIP
ah! ...sorry ...i was confused ...that would be the "throttle position switch"

yes it does affect the computers when closed ....and fully open

the purpose is to indicate to the ignition system ..when you have closed the throttle ...or when you have the throttle fully open .

we have seen on a few occasions this part being faulty ...quite rearely in fact ...but does happen ..

mostly from corrosion and water intrusion i expect ...the connector to this is a little tricky to undo ...but armed with a tiny screwdriver ...the locking clip that surrounds the connector can be released .....be carefull with this as it could fly off ....never to be found again


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

24Back to top Go down   Troubleshooting guidance requested Empty buttefly switch Fri Apr 27, 2012 3:31 am

lesso

lesso
active member
active member
thanks i intend to just renew rather than strip it down. strangley the bike runs ok with it disconected a minor back fire when slowing down but ok.

    

25Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 3:39 am

charlie99

charlie99
VIP
VIP
thats good thing to find ...i would really suggest hanging onto it ...and possible passing it to someone experienced in measuring those things ..auto electrician perhaps ...i have a feeling - suspect that the wide open throttle switch position may be come corroded and be effective (shorting out ) when not actually in the wide open throttle position .....the purpose is to richen up the mixture when in this position ....


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

26Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 4:06 am

nino

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Life time member
Life time member
Chris, my bike didnt start only once in more than ten years. The reason was a moisture in electrical contacts to injectors. Before measuring remove contact with some micro screwdriver and check contacts. If you find any kind of green residues (usualy on the top of injector), clean it and try to start.
If you remove rail and injectors change the rubber rings (8 - 4 on the top on rail, 4 at the bottom in cilinder head)
Looking forward to hear what was faulty.

Best regards

    

27Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 4:19 am

charlie99

charlie99
VIP
VIP
we really recomend a contact cleaning product ..in here on the forum ...we have found that "deoxit" is a really good product to search for .....not only does it clean the electrical contacts it "conditions" them for better conductivity and working operation ...


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

28Back to top Go down   Troubleshooting guidance requested Empty butterfly switch Fri Apr 27, 2012 4:44 am

lesso

lesso
active member
active member
will look product up

thanks

    

29Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 5:05 am

mike d

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Life time member
Life time member
Apparently it is used in the music industry for cleaning contacts, so a decent musical instrument shop may have some, otherwise Google. It's quite an expensive product.

Mike

    

30Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 6:49 am

C_Mick

C_Mick
Silver member
Silver member
Inge K. wrote:About injectors: use a screwdriver as a stethoscope, and listen if they make a clicking sound when turning the starter. If they do, they`re probably clogged.
If not, measure injector coils and connectors (should have 12V+ when turning the starter, same feed as fuel pump), opening signal is pulsed ground.

I have spent a few hours revising basic electrical concepts and how circuits function. The references were helpful. To measure injector coils and connectors as Inge suggested it would help me to know where the probes of the meter must go. As I have removed the tank and I'm working on pulling the fuel rail and injectors is it possible to test the injector coils and connectors by providing current direct from the battery? Replies appreciated as always.

Chris


__________________________________________________
Two wheels good...Four wheels bad...
    

31Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 7:05 am

Rick G

Rick G
admin
admin
You can use 12 volys but dont hold it on there very long just brush it past and listen for a click. When you get the plugs of the injectors there are two small metal tags inside the square part the plug goes in. polarity does not matter.
If you measure thr resistance it will be around 16 ohms but I have seen them as low as 13 ohms.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

32Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 12:22 pm

C_Mick

C_Mick
Silver member
Silver member
I struggled with the fuel rail, trying to pull it away from the tops of the injectors by hand and after several minutes it came off. I then attempted to pull the fuel injectors from their ports but it seemed more force was needed than I could apply with my hands. I came up with an idea for a "puller":

Troubleshooting guidance requested K75S_C_Mick-patented-jnject

A looped cable tie goes round the base of an injector where it starts to widen out...

Troubleshooting guidance requested K75S_puller-in-use

With this simple tool I was able to apply plenty of force and the injectors popped out of their ports like champagne corks (well, nearly)...

Troubleshooting guidance requested K75S_fuel-rail-and-injector

Having opened the metal clips securing the injector connectors (thanks Inge) I set my multimeter to to ohms and put a probe on each of the injector coil terminals. The reading was a consistent 17.3 ohms for each coil.

So I can add to my list:

Works
Injector coils OK (reading of 17.3 ohms for each injector coil)

Now I'm waiting to hear if there are further tests I can do on the injector electrics while the tank is off and the fuel pump connector pulled apart. As always, replies appreciated.

Best regards, Chris



Last edited by C_Mick on Fri Apr 27, 2012 1:27 pm; edited 1 time in total


__________________________________________________
Two wheels good...Four wheels bad...
    

33Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 1:03 pm

charlie99

charlie99
VIP
VIP
hey ..great problem solving chris ...

um.... i havent read yet that the injectors are anything else but the right resistance ....the real problem is the magnetic operation of the valve internally . but the diagnostic strain in all of us demands that we check things to be correct ...and confirm that someone hasnt replaced things with dodgy components .


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

34Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 1:15 pm

Inge K.

Inge K.
VIP
VIP
Since you now got the injectors off,......and confirmed that the coils seems to be OK.

Check connectors for corrosion (also at injectors), measure if you got 12V+ in all connectors while starter button is pressed....and pulsed ground in the opposite (it`s easier to read pulses with a analogue meter, if you got one).

If OK, reconnect them and hold them in your hand one by one while pushing the starter button, then you should feel if they click or not.

Also check the that the inlet in each injector is clean.

Next would be to reconnect hoses and pump, and look at the spray pattern.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

35Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 1:40 pm

C_Mick

C_Mick
Silver member
Silver member
Inge K. wrote:Since you now got the injectors off,......and confirmed that the coils seems to be OK.

Check connectors for corrosion (also at injectors), measure if you got 12V+ in all connectors while starter button is pressed....and pulsed ground in the opposite (it`s easier to read pulses with a analogue meter, if you got one).

Can I do this with the tank still off? Does it matter which probe goes to which terminal of the connector? (Digital multimeter only.) Connectors seem to be free from corrosion. Don't understand bit about pulsed ground.

Inge K. wrote: If OK, reconnect them and hold them in your hand one by one while pushing the starter button, then you should feel if they click or not.

Also check the that the inlet in each injector is clean.

Next would be to reconnect hoses and pump, and look at the spray pattern.

The injector inlets look a bit dirty - as do the outlets. Is it possible to do any DIY cleaning on them? Otherwise I think I'll be OK with this step.

Thanks in advance, Chris


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36Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Fri Apr 27, 2012 3:32 pm

Inge K.

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C_Mick wrote: Can I do this with the tank still off? Does it matter which probe goes to which terminal of the connector? (Digital multimeter only.) Don't understand bit about pulsed ground.

You don`t need the tank or pump for this, as it`s only the electric signals.
If you don`t get 12V+ in the first, try the second........if you don`t find it in any, you have found your problem.
In the opposite from where measure 12V+, you should find the pulse signal.
Set the instrument to resistance (ohms) and look for a change between infinity and 0. (probably you just see a change).

C_Mick wrote:The injector inlets look a bit dirty - as do the outlets. Is it possible to do any DIY cleaning on them?
Inlets is the most importent, you could try carb cleaner.
Others in here might have other suggestions......
If you don`t achieve expected results, send them away for professional ultrasound cleaning. ...... Shocked Alby`s chance for worldwide service Rolling Eyes ...

I would advice you to change all the O-rings, and a careful cleaning of the injector seats in the cylinder head before remounting.


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Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

37Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 7:40 am

C_Mick

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Re. refurbishment of 1986 K75S

Having verified all 3 injector coils are OK I went on to check the voltage is being supplied to the injector connectors:

Inge K. wrote: You don`t need the tank or pump for this, as it`s only the electric signals.
If you don`t get 12V+ in the first, try the second........if you don`t find it in any, you have found your problem.

Test for voltage at injector connectors
Meter set on 20V DC, black probe touching frame earth, red probe on a connector terminal, I pressed the starter. The reading fluctuated considerably but at the higher range e.g. 10.5V to 12.5V. A similar result was achieved for all 3 injectors. (It may be worth noting that a similar fluctuating reading was obtained when I touched the red probe to the other terminal on the connectors.)

Test for injectors opening and closing
I put the injectors back in their connectors and held each in turn in my hand while I pressed the starter. I felt a rapid pulsing vibration from each injector. I double checked using a screwdriver as a stethoscope (thanks Inge) and this time I heard rapid clicking as the injectors opened and closed.


Test for 'pulsed' resistance at injector connectors
Inge K. wrote: In the opposite from where measure 12V+, you should find the pulse signal.
Set the instrument to resistance (ohms) and look for a change between infinity and 0. (probably you just see a change).

I haven't done this yet as I'm a bit confused by the fluctuating voltage reading I got on the 'other' connector terminal.
But in order to do the test am I right in thinking the black probe remains touching a frame earth point and the red probe, the 'pulse' terminal of the connector? Should the ignition be switched on and the starter button pressed, as previously?

Many thanks in advance, Chris

BTW my list can be updated:

Works
All 3 injector valves are opening and closing properly.
Injector terminals free from corrosion
Voltage is being supplied to the 3 injector connectors.

Doesn't work / Faulty
Engine breather hose - rubber is cracking.
Rubber fuel line recycling fuel to the tank (rubber perishing in places).



Last edited by C_Mick on Sat Apr 28, 2012 8:26 am; edited 1 time in total


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38Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 8:03 am

charlie99

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I would advice you to change all the O-rings, and a careful cleaning of the injector seats in the cylinder head before remounting.

yes indeed +1


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

39Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 8:23 am

C_Mick

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@ Charlie, thanks for your comment, I'll definitely replace the o ring seals. Cleaning up the injector ports is slightly more problematical as the gunge goes right down to where the injector seal sits. I'll give it some thought...

Chris


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40Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 8:43 am

Inge K.

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The how to test the coils and electric connectors, was meant to be carried out if one or more of wasn`t functioning.

As you now have verified that all the injectors works, it`s not needed to carry out any further measuring.

About fluctuating voltage in both terminals inside the connector, I`ll guess you have measured in one connector while the other injectors still connected?, all of them have to be diconnected when doing this test.

Next would be to reconnect the injectors to the rail, hoses and pump, and look at the spray pattern. (point the injectors away from the bike).
You should see a fine mist, and no small drops.

The injectors inlet is allready cleaned, I`ll guess?

And get that breather hose changed, if you got a leak here
you will get problems with the engine running.

But that fuel hose is also importent of course......while you have things apart.




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Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

41Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 8:52 am

Inge K.

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C_Mick wrote:Cleaning up the injector ports is slightly more problematical as the gunge goes right down to where the injector seal sits.

Use some cotton pins, which you use to clean your ears now and then.

Not for reuse in the ears afterwards, throw them away.

What.....!!!!!!..speak louder I can`t hear you


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Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

42Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 9:16 am

C_Mick

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@ Inge, thanks for your comments, An 'old dog' is learning many new tricks Rolling Eyes

Inge K. wrote: As you now have verified that all the injectors works, it`s not needed to carry out any further measuring. About fluctuating voltage in both terminals inside the connector, I`ll guess you have measured in one connector while the other injectors still connected?, all of them have to be disconnected when doing this test.

None of the injectors was connected to its electrical contacts when I did this test.

Inge K. wrote: Next would be to reconnect the injectors to the rail, hoses and pump, and look at the spray pattern. (point the injectors away from the bike). You should see a fine mist, and no small drops...

I'll check out the injector spray pattern next; a new breather pipe, new o ring seals and fuel hoses are on my 'to do' list.

Best regards, Chris


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43Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 10:00 am

Inge K.

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C_Mick wrote:None of the injectors was connected to its electrical contacts when I did this test.
Could be that the overall voltage is fluctuating a bit, due to varying load on the starter motor.


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Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

44Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sat Apr 28, 2012 10:45 am

charlie99

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a digital meter ..while is verry acurate ...is terrible for checking fluctuating voltages ...the numbers just roll over ... giving the user no idea ...

might be a good idea at this point to check the efi trouble shooting thread in the portal page ?

just to get an idea of the flow chart

but with gunk caught in the filters atop the injectors ...could certainly be an issue here

they are finicky to remove ...a correct size wood screw (tech screw) threaded into them and good set of pliers is often needed ...but dont go there unless you have relacements on hand .....carbi cleaner might flush out some of the nasties ....but yes check the spray pattern for flow at a minimum

i would recommend replacing all the rubber leading to the injectors ...from the output fuel filter in the tank at a minimum ...we dont want further flakes of decomposing rubber stuffing up any good work that may be corrected


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

45Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sun Apr 29, 2012 11:10 am

C_Mick

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charlie99 wrote: ...check the spray pattern for flow at a minimum. i would recommend replacing all the rubber leading to the injectors ...from the output fuel filter in the tank at a minimum ...we dont want further flakes of decomposing rubber stuffing up any good work that may be corrected

Thanks Charlie, I will replace the high pressure fuel hoses which connect to the exterior of the tank ( those inside it seem OK). Does it work to buy generic high pressure fuel hose or is it best to buy the BMW parts which are presumably cut and pre-formed to fit exactly?

I've become adept at removing and replacing the tank, but I'd like to check my understanding of the routing re. the 2 spigots shown in the photo below:

Troubleshooting guidance requested K75S_fuel-tank

There is a receptacle (sink) under the tank, in approximately the right position to mate with the 2 spigots; do they go into the sink directly or should there be a short length of hose attached to them?

But back to the troubleshooting:

Today I tested the spray pattern of the injectors, having connected up the the electrics and fuel hoses. The good news is that I observed an atomized spray of petrol from all 3 injectors.

So I can add to my list:

Works
An atomized spray of petrol appears from all 3 injectors when ignition on and starter button pressed.

The bad news is that I'm stumped as to why the engine would not fire up with a spark at the plugs and fuel supplied to the cylinders. I've learned a lot so far, and when I have sourced new o rings I'll put the injectors back in place. Should I wait until then to see if the engine fires up or are there some further checks I could usefully carry out?
Replies appreciated,as always. Chris


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46Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sun Apr 29, 2012 11:57 am

Inge K.

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C_Mick wrote:Does it work to buy generic high pressure fuel hose or is it best to buy the BMW parts which are presumably cut and pre-formed to fit exactly?
The only hose that is pre shaped is the return from the FPR to the tank, but I`ll guess you could use a ordinary high pr. fuel hose also on this one.
I have only experience with the pre shaped ones, scheduled change out (every 8 year).


C_Mick wrote:There is a receptacle (sink) under the tank, in approximately the right position to mate with the 2 spigots; do they go into the sink directly or should there be a short length of hose attached to them?
No hoses is needed on the spigots, it should be one attached to the bottom of the plastic cup...which end out below the RHS footrest bridge.


C_Mick wrote:The bad news is that I'm stumped as to why the engine would not fire up with a spark at the plugs and fuel supplied to the cylinders. Should I wait until then to see if the engine fires up or are there some further checks I could usefully carry out?
No suggestions to other tests at this moment........but is it totally dead, or is it some small signs to a almost start up?
What I have in mind, is what Charlie earlier mentions.....
that it maybe fires on the two cylinders that is dry, but not on the last one.......
do you have a strong blue spark on all three cylinders?


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

47Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sun Apr 29, 2012 1:26 pm

nino

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Hello Chris, just remembered the situation when my bike wont fire up. Reminds me on yours. Everything were OK, spark, fuel, injectors, full battery...I tried for two or three days of pushing the button. Nothing. Finally found that one brown wire (ground) under the tank was interupted. When connected thart engine fire up at once

God knows, check that wires. Good luck

    

48Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sun Apr 29, 2012 2:15 pm

C_Mick

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Inge K. wrote: No suggestions to other tests at this moment........but is it totally dead, or is it some small signs to a almost start up? What I have in mind, is what Charlie earlier mentions.....
that it maybe fires on the two cylinders that is dry, but not on the last one.......
do you have a strong blue spark on all three cylinders?

Thanks for your reply Inge, when I checked for a spark at the plugs I tested # 3 cylinder only and assumed the others would be fine. I will check them all and observe whether a 'fat' blue spark is present. To answer your question, the engine was totally dead, no sign at all of it wanting to start. And thanks for your comment Nino - I'll check if any wire have been dislodged.

(Ideally I should like to have the injectors serviced while they are out, but the nearest facility offering ultrasound cleaning is in Cape Town, approximately 250km away. As the injectors apparently work OK I think I will re-install them, but first replace their o rings.)

BTW in the Troubleshooting Guide I think I read a note to the effect that it could be worthwhile disconnecting the "butterfly switch" when the bike will not start / is difficult to start. I suppose doing so would eliminate it as a possible cause of the problem?

A final question for this evening: the Haynes manual stresses the importance of de-pressurising the fuel line before disconnecting any component part of it. How important is this and how best to do it if I need to?

Best regards, Chris



Last edited by C_Mick on Sun Apr 29, 2012 2:28 pm; edited 2 times in total (Reason for editing : Add information)


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49Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sun Apr 29, 2012 4:15 pm

Inge K.

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C_Mick wrote:BTW in the Troubleshooting Guide I think I read a note to the effect that it could be worthwhile disconnecting the "butterfly switch" when the bike will not start / is difficult to start. I suppose doing so would eliminate it as a possible cause of the problem?

It won`t hurt to try that. But I`ll guess Bert have a shorted full throttle switch in mind on this one, and it would give a richer mixture....and more a hot start problem.



C_Mick wrote:A final question for this evening: the Haynes manual stresses the importance of de-pressurising the fuel line before disconnecting any component part of it. How important is this and how best to do it if I need to?

It`s quite important if you`re fond of cigars.....and like to have one when puzzling around serving your bike.

When disconnecting the hoses when under pressure, you have possibility to spray fuel around where you don`t want it.

What I do when such a task is needed on any fuel injected engine, is to remove the fuel pump fuse and run the engine until it stops.
But you then need a engine that starts, though.


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Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

50Back to top Go down   Troubleshooting guidance requested Empty Re: Troubleshooting guidance requested Sun Apr 29, 2012 7:58 pm

C_Mick

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Inge K. wrote: It`s quite important if you`re fond of cigars.....and like to have one when puzzling around serving your bike. When disconnecting the hoses when under pressure, you have possibility to spray fuel around where you don`t want it.

I think I would still enjoy a good cigar, but haven't had one for over 20 years. I've told my wife I'll start again when I reach 75. Something to look forward to - the cigars I mean... Smile


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