So I'm slowly chipping away at my 93 K1100LT restore/conversion project. I've got most of the electrics figured out now, but when I go to start the bike I only get a few pops from the exhaust followed by a hiss/pop from what seems to be the forward most fuel injector. Could this be due to a battery issue? Seems to me like it is probably electrical, but I'm not sure where to start trouble shooting. Any advice would be great! Hope to have a runner here soon.

Christian

I think if it was the battery being flat you would here the starter clicking and no engine turnover. The hissing/popping sounds like you might be losing compression. Check the injectors are fitted correctly. Are you getting a spark & good fuel supply to the cylinders?

GMcQ

We need a little more info than pop/pop, to help you with the troubleshooting.

Do you have spark at all plugs....be shure to have good ground at the plugs
when testing...or you could fry the ignition output stage.

Does fuel reaching all of the cylinders...

What does your sparkplugs look like...colour....wet...dry.

Does the vacum/ventilation/oil separator hoses at the rear of the TB's look
healthy w/o leaks.

Is it a early or late -93........if it's the early version, you have a ignition amplifier
at left, front of the battery....as shown in the drawing.

The bike is early 1993 and it has the ignition amplifier on the battery box (no clue what that was until Inge K. enlightened me!!!)

So I have replaced the plugs with NGK DPR7EA-9 plugs. The Bosch plugs I pulled did have signs of carbon deposits, but were overall tan and also wet which is why I suspect the ignition side of things to be weak. I am going to test with an inline spark tester as soon as I have a chance to work on the bike again. I am also considering flushing the tank and replacing with known good fuel rather than trusting the residual which is currently in the tank. Other thoughts lean towards the Motronic unit since the wiring harness wore through on the back tire under the previous owners watch. Not sure how to test this though and want to rule out all other options before I look into the Motronic. Have replaced the entire ignition system wiring harness since.

Thanks for the help guys and I will keep you posted as I work through my troubleshooting!!!

Christian

The plugs should be DR7EA the P means a projected electrode and will raise the combustion chamber temp.
I have seen holes in pistons that were caused by projected electrode plugs. Mind it probably wouldn't hurt a K11 but if you were riding hard on a hot day it would increase the chances of detonation and so damage to the Nicasil bore.
I am currently waiting delivery of an Ignition Amplifier for my K11. Had to buy one to test as I couldn't even find someone else with one I could borrow.
Make sure you use heatsink paste under it before bolting it down or the heat will kill it.

So update is that plugs looked wet definitely smelled of gas. The color looked good not black. Puffing a lot of smoke but no light off. I've also tested the injectors manually by applying 12v directly to them. They all clicked as they are supposed to. I have also cleaned electrical contacts. Not sure what to try next....

probably something you have already checked but if I am correct the water temp sensor ( behind radiator certainly in a K100) is disconnected or faulty the info to the ECU can cause an incorrect fuel mixture....checked the coil/ht lead resistance?

What I know to be true is that you need good spark and a suitable fuel /air mixture for good combustion....vacuum leakage, and dodgy fuel are not condusive to a good mixture...too lean or too rich is not good...here is a thought...have you tried "start you bastard" which is a cold temp starter fluid like ether...I know you can get engines to run with no fuel with this product sprayed into the air box ( filter removed). this would indicate that the ignition side of the house is acceptable, and cleans stuff too...When I picked up my sons bike in a number of boxes helped him put it together this is how we started in for the first time...and after that some fine tuning.



good luck mate

Good advice. I purchased some starting fluid to see if I can get this bike to show me a sign of life. I re-gapped all the plugs and checked the spark. Looks nice bright blue so hoping to eliminate the ignition system as the problem.

I also bought some sea foam to see if that helps. As you guys can probably tell my troubleshooting has now resorted to dumping chemicals into my bike . Will post results.

Looks like one of the exposed wires was to the water temp sensor so that may have caused some problems too. Will post my results!!!!

Sea Foam and starting fluid seemed to have little impact. Still getting smoke out of the tail pipe, but no light off. Looks to me like cylinder #3 is black on the plug compared to the other three. I also installed a fuel pressure gauge. When I turn the bike on I get the 36 PSI that I'm supposed to, but the pressure falls off quickly thereafter. If I press the starter button the pump will bring it back to 36 PSI. Not sure if this is normal. There are no external fuel leaks. I've had plenty of time with a toothbrush and engine cleaner to polish the bike up just hoping to have a brilliant idea while I sit there scrubbing away to get this thing started.....

Because a picture is always worth more here's what the fuel gauge setup looks like. Very pleased with the quality and price of this product.

So still haven't had that moment of divine intervention yet to help me get this bike going. The good news is that I have since removing the ABS system performed a brake bleed and it works great! So much more simple to do as well. Probably get about 100 pounds off the bike with all the ABS wiring, modulators, etc...!!!

I decided to go ahead and do a compression test today just for fun. Every cylinder showed me around 165 PSI +/- 2.....except for that time I forgot to hold the throttle wide open and almost had a heart attack when I saw 120 I'm sure I will make plenty more mistakes like that on my way to completing the restoration.

I pulled the plugs again and found them to be black and wet this time. I presume some sort of rich mixture problem here. I also checked for spark again and this time I saw nothing on any of the 4 cylinders. Strange....this is over the course of a day. I checked resistance on my coils primary and secondary and got the 12.65Kohms and 0.5ohms as per the repair manual.

I also had another new issue where my Acewell gauge would actually stay on when I returned the kill switch to the off position. It would remain on even with the ignition off. If I put the bike into run mode with the ignition off the fuel pump would come on and remain on until I cycled things a few times.....something seems a little sticky. When I removed the Motronic control unit the ignition and the Acewell unit worked as advertised. I broke open the Motronic just out of curiosity and it looked to be in great shape...no moisture....no visible issues. I have a replacement on order just in case, but not sure what to check next......



So there she remains in the garage can't wait to get this thing running! Just about everything else is coming along nicely.

so close but yet so far....you are winning mate as everything is a learning experience.....you watch it will be some tiny little gremlin...such as a fuse or lose wire ...

You are probably right. I have been pretty diligent about checking wires, cleaning contacts, and keeping an eye on those fuses as that is about the extent of my electrical expertise!! The baby is asleep so no more starting attempts until tomorrow :-)

Hey guys,

So during the starting cycles I noticed some smoke coming from the ground on the transmission case by the coils and battery box (left side). It appears as though the hottest wire is the long ground that goes to the central ground location under the tank. The battery ground felt cool to the touch, but the ignition coil grounds felt warm....could be heat spreading from the long ground wire. So as this is happening while attempting to start are there any obvious places to start looking?

Clearly I have high resistance in that ground for some reason?

Have you got piddly little brown wires connecting to the coils?

I believe it was either a mod or a change that the earths were beefed up on the coils to uninsulated braded wire

They are black insulated ground wires that look to be similar in size to most of the rest of the wiring on the bike. Certainly not what you are describing. Should I change them?

just double checked yours is the K1100 not the K100 so not 100% certain about the earth for your coils (That was me missreading) .... Also reread your post...

The Earth in question is the same on both models what it is suggesting is that with repeated starting of the starter motor there is lots of current being drawn down that one cable. Under normal conditions this wouldn't be a problem as 1-2 seconds later you would release the start button and the starter motor is no longer drawing a current.

I wouldn't worry about it too much however (in the same sentence) as you have seen smoke that means that damage has been done probably to the insulation only. You need to check the wire is all intact and be aware that it will heat up with repeated attempts to start it.

I upgraded all of the main earth wires on my K and there are aftermarket one's available.

I think I will go ahead and replace that ground cable just to be on the safe side. I thought that repeated starting attempts might heat things up a little!!!

1-2 seconds to start sounds amazing cant wait to figure this thing out!! Just pulled my plugs again and all four are pretty darn wet and black...

Just noticed that no-one has commented on your Fuel pressure reading...

I thought the pressure regulator is just that it should regulate the pressure of the fuel being allowed to pass and hold it at a constant level.

I have not been able to test this as I am only just about to order a kit to test the fuel pressure.

If the line is pressurized when the ignition is turned to on then this would suggest a problem if it drops quickly.... I am sure that Bert says his holds it's pressure for over a day...

Wet plugs suggests to much fuel.... which would in turn give a rich mixture.... i would have thought the injectors should be in an off condition until the bike demands them to inject fuel at the same time as the ignition fires.... a dodgy earth could be allowing the injectors to pass fuel when they are not required to...

That was my thought with the pressure not holding combined with black plugs. Could the moronic be the cause of this? I ordered a new one which I am expecting tomorrow as I suspected an electrical short under the previous owner could have damaged it?

Thanks for the replies by the way a second opinion is always appreciated with this thing!!!!

My K100 never held pressure for more than a minute or so but the K75 holds for days. The only difference is that it takes about an extra second to get started waiting for fuel pressure to build. With a K1100 or any 16v the pressure should be there for the start because the pump starts when ignition is turned on and not when the starter is pressed.

The regulator is a passive device so wouldn't be affected by the electronics.... and it is this which would hold the pressure at a constant level. It would be nice for someone to clarify what you should see at each stage ie:

1. Ignition off having de-presurised 0
2. Ignition on 36
3. Ignition on starter button pressed 36
4. Igniton on bike idling 36
5. Igniton off for 1 hour 36

The red numbers are what i would expect to see... 36-38

The switched earth to the injectors which i think is still a common earth on yours is as you say from the moronic... there is only a short amount of cabling between the EFI and injectors and a visual inspection followed by a quick continuity check would prove the cabling is ok.

That answers a chunk of that then Rick the test number 5. could vary between bikes then

I would say the FPR was on the way out but it still ran well just didn't hold pressure because of a tiny weep at its seat.

Fantastic! So would I need a pin out for the moronic harness to do my continuity check? I'm not sure which pin corresponds to which injector/EFI component which has been a cause of delay for me.

I get 36 PSI right way when I turn the kill switch to the run position. Without depressing the starter it depletes to 0 almost instantly. When I depress the starter button ,y pressure gauge goes back to 36 while engaged. Haven't been able to take a look at idle yet as I haven't gotten that far.

Amazing how clean you can get a bike while pondering these issues! Or how dirty it was I should say

Just say that the regulator was kaput ( not regulating down to 36 psi)...you would get 60 odd psi at the injectors which cycle and are flow limited so how would this make it a rich environment?..only if the injectors are ordered to be open all the time....so this would take us back to the "brain" which is controlling this process badly..or the sensors the brain uses are faulty...is this hypothesis valid?

60 psi will go close to doubleing the flow and at very rich opening times for the injectors will make it very rich.

My inline gauge only ever reaches 36 PSI so I don't think I'm getting 60 at the injectors....however because I'm losing fuel pressure so fast my inclination is towards the injectors stuck open?

I've tested them manually and they all fire which took me closer to the motronic. Not sure if that logic makes sense I'm just trying to learn this bike.

I see your point there that a regulator works as a limiter.... so going to 0 would mean the fuel is escaping... only 4 ways it can leak out and that is

Out through the injectors
Back to the fuel tank
From the fuel tank hose
out of the FPR.

The last 2 would be noticeable I would have thought.

Back to the brain... that's the only thing that tells the injectors to open and close other than when they themselves are leaking.

It is possible to use a scope to see if the injectors are being told to open and close. its possible that they could all be leaking it could be proved by taking the rail off with the injectors still on the rail and seeing if fuel leaks when the ignition is on "NO Pressing the Starter"

As Rick added double the pressure and your likely to be passing the Max amount of fuel possible through the injector if the pressure is outside of the working design of the injector it could cause a delay or prevent the injector switching off...

I've attempted to remove the fuel rail and injectors previously. It was taking more force than I was comfortable with the pull the rail and injectors. I had removed the 4 metal clips for removal. Are they typically stiff? I did not want to damage o rings since I didn't have replacements on hand.

Also no noticeable fuel leaks from the injectors or the regulator as this is the first thing I investigated.

yeah they can be a pain in the arse to remove.... I would be prepared to replace all 8 O rings if you were to remove them..

Figured. As I a expecting arrival of a new brain for the bike tomorrow I might wait until after I've tried that. Local auto parts stores usually have the o rings?

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=40&Ct=FA&SbCt=BA_15_40_FA_50&spPage=2


http://www.motobins.co.uk
this is where I get mine which apparently do ok with ethanol...although I try not to use it...

So is the fan supposed to come on right away when I place the bike into run? I just plugged in the fan today and it kicks on as soon as I place the bike into run. When I press the started button it turns off until I release the started button and it comes back on again?

I'm thinking if the fan is not supposed to come on immediately when the bike is placed to run (cold of course since it's not been run yet) this could point to a temp sensor or the motronic control unit again? Thanks guys!

The fan "will" only come on when the water is getting very hot (can't think what the temp is)

The quick answer is nope it shouldn't come on...

I am not sure what gives the signal for the fan to come on, but am looking now!

Have a look at the electrical diagrams as well.. You will see that the reason the fan stops when you press the starter is due to the load shedding relay doing it's job.

Hope that helps figure out which way to go...

I can see the fan relay and then I also see from the relay a wire going to the Motronic. The other two wires in the loop appear to be ground and to the fuse box. I presume the Motronic is where it gets its signal from, but I'm not sure what the Motronic uses for the fan. Must be the coolant sensor from what I can deduct. I did unplug the coolant temp sensor to see if this would cause the fan to turn off, but it did not. At least this is another clue as to what's wrong with my bike!!!

I wonder if a bad ground somewhere could cause this too?

yeah thats right the coolant sensor that is just behind the radiator, there is a simple resistance check that can be done on it.

I am not 100% but I guess your sensor is the same as the K100 2V in that it is a dual sensor, when you measure the resistance you measure between earth and one pin then earth and the other pin... That way your testing the sensors individually.

the signal going to the motronic is probably just information rather than telling the fan to turn on... I would think the signal to turn the fan on is from the temp monitoring unit...

Perhaps the fan relay is faulty (i.e. already operated).

Mike

Good point Mike thanks I will take a look at the relay as well. I think I will do the resistance check on the coolant temp gauge behind the radiator as well to start ruling out components! The good thing is I feel like I am starting to understand this bike a little better!

Also just saw that my new Motronic unit is out for delivery. Would you guys recommend not plugging that in until I've done further troubleshooting? Or do you think I would be safe to plug it in to the harness to see if that solves all of my problems (wishful thinking of course).

The main inputs to the motronic are the airflow meter, idle switch (TPS), water temp sensor and electronic ignition, and of course a lambada sensor for the exhaust. The o/p is to the fuel injectors...

There would be no harm in doing the tests on the airflow meter to ensure it's performing as it should do.

If I understand correctly the leads should have a fixed level of resistance so it's probably worth checking that they are good showing the right resistance... other than that I would go ahead and drop it into position and see what happens....

I have a feeling the fan problem will still be there however for the purpose of getting the engine to idle that won't be a problem..

So I swapped the horn relay with the fan to see if this was the source of the problem. The fan did not come on with horn relay in place. However, when I put the fan relay in the horn slot the fan came on!!!! I presume that is not normal?!

New motronic unit is in. The fan issue is now resolved by installing the new computer so something was definitely wrong there. Still won't run so I back to troubleshooting more parts.

If you PM me your email address I can send a PDF file with a heap of info about the motronic and fault codes which will give you a far better chance of finding the problem.

Sent with other useful stuff

Thanks got it. I will start assembling that tester once I get the parts for it. Should point me in the right direction!

Update guys getting motronic error code 1133 and that's seemingly the only one that's tripped. Looks like a hall sensor #2 no signal code.....how to proceed?

You can fix by replacing the sensors from this mob
http://www.bbautomacao.com/home_hall_effect_sensor_cyhme56.html

What sensor part # does the K1100LT use?