Hi all
I just stripped my bike and fitted a new temperature sender unit, the one for the fan and fI computer, and a sender unit in place of the drain plug.
I cleaned all connectors again, checked all resistances etc from temp sender and air flow meter and everything is fine.
set idle to about 1000 rpm then set the idle switch so i could hear the click and everything is running great.

Now when i press the start button the bike starts and ticks over superb without having to touch the throttle and it revs nice, the temperature gauge is working too.

Now the problem.
I took it for about a 10 mile spin and the new gauge started to go to 120 degrees, i put some petrol in and when i got home it wasnt running very well, when i stopped and started it, it wouldnt idle running very rough, so i let it cool and tried again but still no good.
i removed the spark plug coil cover and the hall censor covers to check and now it wont start at all.
I removed the thermostate and tried it in some hot water and it didnt move, so looks like the water wasnt cooling down.

Would overheating burn out the hall censor? is there a way of checking them with a meter instead of the led test?
Also i checked a spark plug against the earth of the engine and im not getting a spark.

This is so annoying as the engine was running sweet when i put everything back together.

Sorry for the long post but thought it would be best to explain everything i have done.

There is an overheating protection on the bike. It'll run untill too hot, but once you've stopped here she won't start until cooled down.
Further, stupid question, but we've all been there - is the ecu plug properly seated?

Yes everythings seated properly, i had left it over night to cool but it still wouldnt start. i can smell fuel but im not getting any spark from the plugs.
Am in the process of getting the l.e.d test rig made to check the hall sensors.

No spark from any of the plugs? The hall sensor triggers two pulses, for the 1-4 and the 2-3 cilinders and it would seem odd if suddenly both sensors (there are two on a plate) pack it in. Have a look at your injection ecu, the little box fwd under the tank the connector is OK. I know I'm going on a bit about connectors, but those are 80% of the problems with these bikes.

Thanks Renez, i have checked all connections and all seem fine, the strange thing is it was starting but running really rough, as if it was only firing on a couple of cylinders until i took the cover off the hall sensor, then it just wouldnt start anymore.

I took this cover off originally to run the cable through for the temp gauge but the cover went on ok and it ran great until it overheated.

I cannot believe the price of the hall sensors, why are ours so expensive, on ebay other bike sensors are aroung £20 ours are like £190. doesnt make sense.

If it ends up the sensors are gone i have found this place has some, http://www.chenyang-gmbh.com/ for 10 euro each. will replace them myself, has anyone had any dealings with these or know anything about them?

badgerdid wrote:... why are ours so expensive, on ebay other bike sensors are aroung £20 ours are like £190. doesnt make sense.

If it ends up the sensors are gone i have found this place has some, http://www.chenyang-gmbh.com/ for 10 euro each. will replace them myself, has anyone had any dealings with these or know anything about them?

Welcome to the world designed to extract $$ from people who are not in the know... I understand that these sensors are a common and made by someone well known. They are cheap as components, but VERY expensive as OEM parts.

Someone like CF will be able to give you a full account of this, I am sure. I have feeling that if you look at the CF's rebuild pages you will find that info. Above all do not spend 190 for them!

The sensors reference # is 2AV54.
If you search on Google, you will find plenty of suppliers.
The first Google result that I looked at is a company selling them for $15.00
check there!

I totally agree with ReneZ about the sensors. Unless you had a major short circuit, I cannot imagine that you burned 2 sensors at the same time.
The problem should be somewhere else.
when you turn the ignition on, do you have the temperature light glowing?

Hi, well i tested the sensors today with the LED and they seem to be working fine? lights up then when i put the feeler gauge in between the light goes out.

I dont have the temp light come on with the ignition, only the normal lights, oil and battery etc. i dont think i have ever had that light come on.

Im wondering wether to change the temp gauge back, could the new one have failed with it getting hot? i read somewhere if its not working properly it wont start, but then the meter reads about the right ohms for the ambient temperature.

I also wonder if i may be going down the wrong path, i only think it overheated because of the temp gauge i fitted went to 120, but how do i know if this is working right as it isnt a default bmw gauge, but its the bmw sender unit from motoworks, will they read right?

What is the max temp on your gauge? There are two types (basically) ones that go from 40 to 120 and ones that go from 50 to 150. The sensor is to be used with a 40-120 gauge.
The reason for asking if the red light comes on when you put it on contact is no doubt concerning the ECU not allowing the bike to start if it gets a signal that it is overheated.
With regards to your doubt about the overheating. If there is sufficient cooling liquid in the system, when it heats up, after the thermostat is fully open and it continues to warm up the fan will come on and some time later the red overheating light. If heating up continues then, due to expansion or cooking, the cap will open its overpressure valve and the system will 'blow of' through the hose into the container on the right side next to the battery (if the hose is tight). You would notice this through bubbles in the sight pipe and sometimes spray coming from the tank lid. Hope that helps a bit.

Further to the above - re the sensor/gauge - 50 Ohm sensor resistance gives a 90 C indication on the 40-120 gauge and about 113 on the 50-150 gauge.
If you measure the right resistance between pins 10 and 13 at the ECU (about 2500-3000 Ohm) it means that the sensor gives the right signal (at outside temp) and should allow the bike to run.
The fact that the spark plugs don't spark has to be something else. Have you had a look at the connectors underneath the coils? If you start (when it worked) does the rpm gauge give indication? I'm starting to wonder if there is an issue with the isolation switch/starter button.

Best thing to do here is start at the beginning and trace the volts down the wires following the diagnostic path shown in CF's excellent fault finding diagnosis step by step process.
Regards,
K-BIKE

Tested today and done the tests at the temperature testing unit and everything worked as it should, the fan starts when i jump 15(45) and A2 and when i go from A3 to earth the temp light comes on, so at least i know there working.

Dont understand now why the gauge showed 120 i just fitted, might need to try another to see if its faulty.

K-BIKE, looks like the step by step process is the only thing i can do now. i checked the coils were getting 12v too and they are receiving 12v on the green/yellow wires.

The only relay that clicks when i turn the ignition on is the shed loading relay, is this correct?

hello guys.
try to see if the brown ground wire directly the rear of the gauge is doing is function, if you have doubts put another one direct to the framme and test.Good luck Badgerdid

best regards
Paulo k100

Any luck yet badger?
Taking a broad view
it appears the bike was fine until you fitted the temp senders
then it all went pear shaped

Providing the EFI temp sensor you fitted is electrically similar to the original
I'd have to echo Rene's point about connectors.
They do get the weather in and I struggled with a simple one I knew affected
the front indicator until I got the sod to work properly.

It may be worth dismissing any assumptions and rechecking them again
Also check the latching terminals dont get pushed back in the connectors when they're
mated up. I've had that happen on some systems and its not always apparent

Good luck with it !

Not yey, cant get to look at it till monday. I am going to test everything is working as should be, connections from ignition control and fuel injection etc.

Well tried another hall sensor and still no look, although i have not fitted the temp relay yet, next is the ignition ecu under the tank, if that dont work then im stuck, will have to take her somewhere to be looked at properly.

Anyone have a ignition ecu spare i can buy?

thanks

Hi,
Did you go the the bike not starting page in the download section and exactly follow the step by step process otherwise you are running the risk of throwing parts at it till it works and if the problem is something like a bad ground up under the tank (number 9) or a bad connection at 5,6 or 3 or to the bar switches then it won't run even if you put new out the box components at the end of the wire I know it's a pain to follow the step by step process without jumping any steps but diagnosis is like that, look at the chart, if your starter is spinning the engine over then go to the next step starting at the first blue box double check everything and then follow the green line to blue box number 2 and then the green line or the brown line whichever applies. Bert has assembled a really good resource there and it works, keep the faith you will get it running.
Regards,
K-BIKE

Well im even more confused now,
a m8 came and had a quick look, we took the plugs out, checked all spark plugs against the engine, no spark as usual so at least we thought its not sparking for some reason thats the problem.

He went so i thought i will put the plugs back so i dont get anything in the holes, tried it and it started?

now its starting again at the touch of the button and ticking over?

strange, i just dont know what it was, what caused it or anything. but at least its running, have not took it for a run yet though, at least i have a lot of spares, lol.

Anyone have any ideas?

The only thing i noticed when i took the plugs out is they were full of petrol, which i would have expected as i had been trying to start it, but other than that i did nothing different.

It may have been that simple that it "flooded". I have only had that once but others may have come across it before as Bert has an interesting method of curing it with a blowtorch.
These bike are not that sophisticated in that if you keep trying to start they will happily keep pumping fuel in so with any luck that is all that it was but keep us posted.

I agree with Phil keep us posted and meanwhile work through every electrical connection and earth with DeoxIT.
Regards,
K-BIKE

badgerdid wrote:The only thing i noticed when i took the plugs out is they were full of petrol, which i would have expected as i had been trying to start it, but other than that i did nothing different.

Just a word of caution: If you had repetitively tried to start the bike without success, it's time to check your oil level.
Yes!
This spring I had a similar problem, but it was my own stupidity (The plug for the Fuel Injection computer was not clipped correctly).
I had to push the starter for 5 minutes before the bike would start and then it would run on only 2 cylinders. I had gas, sparks and no go! When I finally found the problem, I went for a short ride but my 7 liters gas light started to glow at 130 km. This was very odd as I normally ride about 220km before seeing the 7 liters light.
I went back home and let the bike cool down. I then check my oil level and it was up by about 1/4". again .
I think that with the EFI plug dislodged, the injectors were continually pumping gas and filling up the cylinders. Gas was then passing the rings and entering the crankcase.
I had to replace the oil and filter (it was only 30 km).
I was lucky as I caught it right away and didn't damage anything. The engine got a good flush.

Where you have plugs to the computer units it is a good idea to use a long plastic tie to retain its connection at all times.
Just poking my nose in.
Ajays

The L-Jetronic plug has a clamp, as does the motronic I think. You can see it through the little hole in the tool tray above it. I always look through the hole to see the clamp open and close over the pin on the connector. You should not be able to unseat the plug without having to push the clamp back. If you can it is not seated properly.

I said that it was my own stupidity .....
I just replaced the battery and didn't pay attention when resetting the computer's plug. If the injectors had stop working, this would have been the first think that I would have checked.
What I still cannot understand is that the injectors were delivering gas when the plug was not properly set.

Bert, wasn't having a go at you, just sharing some. Don't know if all know about the peephole above the plug.
Re injectors, do they get their signal also through the injection computer or only from the ECU?

ReneZ wrote:Bert, wasn't having a go at you, just sharing some.

Rene,

This was a pertinent remark talking about the peephole. I don't think it was ever mentioned on this forum.
My advise is that when you put the plug back on, remove both side panels, hold the back of the FI computer and firmly push the plug in until you hear the 'click' of the clip engaging. Hey, this is experience talking!

Yes, the injectors receive their signal solely from the FI computer. They get a constant positive power from the FI relay and the FI computer controls the negative. This is why I still cannot understand why they were energized.

Bert, no worries. I'm trying to help an Aussie stranded in Oban with a K75RT which initially was dying on him over 3k rpm and now doesn't want to start, bit strange. I think its fuel starved, but he's still to come back after some testing/verification.

As for the FI plug the simplest thing is to forget the peephole and slide the unit out far enough to see the whole plug assy and then you know for sure.

In some case the plug itself can be broken where it latches and then the best option is AJAY's suggestion.

Bert in your case I suspect it was just enough contact to be a PITA and then happily disconnected itself. I have lost count of the times I have fixed problems by disconnecting and re-connecting connectors.

There is no need to disturb the plug.
I have just replaced my battery for the Gel type.

Go round to the brake pedal side of the bike and
squat down looking at the end of the battery
Remove this screw and its rubber washers completely
Go round to the gear lever side of the bike and squat down looking at the end
of the battery
Remove the cover on the end of the ECU unit below the tool tray
Directly in front of your eyes is the connector
mounted on a cable.
Follow the run of the cable and snip away any zip ties holding it to the frame
The entire ECU box with cable attached now pulls straight out
Wiggle, the tool tray out
Disconnect the battery terminals - first negative and pull it out

Ajays

...and replace the zip ties with black ones to match the frame hey Ajays...

Blakey,
OK OK I will change the white ties on my K100RS when I change the battery on that one.
I sometimes wear brown shoes with a black suit.
Cheers Ajays