K1100 died, cranks but will not restart, fan blowing with engine off?

[unknownroad]

Hey all,

Hate to make my first post an "OMG PLS HELP," but i'm running out of ideas short of taking the harness apart wire by wire or throwing a new computer at it with my fingers crossed...

Background- 1996 K1100RS, 26k miles, had it about 8 months, only had time to do around 500 miles in that time.  :dunno Bike seems pretty unmolested, side stand switch is bypassed. 

Tried to start, battery low but not dead. Disconnected computer, charged with smart charger, belatedly added a pigtail for my trickle charger, bolt it back together, it starts fine and we head out. Running a little sputtery under load, but i figure it's older gas.
About an hour from home, engine cuts out with no drama and we coast to the shoulder.

Try to restart, cranks strong but no start. Visually check the gas to make sure the gauge isn't lying, it's not that. I notice that the fan is blowing hard with the ignition on, even though it's a mild day and the temp was reasonable when it quit. I left the house with no tools, since i'm an idiot (where DO all the factory tool kits go?), so i have the thing towed home to mess with it there. i figure i must have fouled up some wires when i had the battery holddown off, and i'll find a short or bad ground in a couple of minutes.

Nope.

Checking it now, with key in "run" position, engine is stone cold, gauge reads cold, but the fan is still blowing up a storm. I can hear the fuel pump priming with my ear to the tank.
Hitting the starter button gives me a decently fast crank, but not a hint of ignition. It does get the fan to pause while the starter is cranking. Fuel pump seems to be putting out a decent volume as it cranks.
All the fuses look fine. No scent of magic smoke in the relay box.

i spent a couple hours searching and reading the archives thinking i can't be the only person with these symptoms... but i seem to be the only person with these symptoms.

Any suggestions?

Thanks in advance,

...dave

[kioolt]

Check your computer connection since that seems to be the last thing you did.

[johnny]

greetings unknownroad...

was it on a battery tender the 8 months you had it before you tried to start it... if not its proally the battery... or you have it in fan test mode... does the horn sound when you press the button... do your turn signals work when you press the buttons... does the fan stop when you pull the fan fuse...

http://www.motobrick.com/index.php/topic,5678.0.html

http://www.motobrick.com/index.php/topic,7479.0.html

http://www.motobrick.com/index.php/topic,7480.0.html

http://www.motobrick.com/index.php/topic,7932.0.html

welcome to motobrick.com...

j o

[Martin]

Could be the temp sensor with the K75's & K100's you can pull the fuel pump fuse and get them to start. I have just finished playing with a K75 and that was one of it's problems.  Not sure if K1100's are the same. Do you have spark.
Regards Martin.

[unknownroad]

Thanks for the ideas so far... i guess i should have mentioned that i checked the computer and fuel pump connectors first off, they were clean and tight.

Signals work, horn works (always forget how damn loud that is). Fan cuts off when i pull the fuse. Pulling the fuel pump fuse didn't help (did you mean fan?). With fuses 5, 6, and 7 out (motronic, fuel pump, and fan) i could hear a clicking coming from the relay box with the ignition on- not quite every second.

Have spark on all 4 plugs. I was surprised to find that i had spark as soon as i turned the ignition on, even before i hit the starter- not sure if this is normal? i'm used to working on breaker-points stuff. Plugs all looked good, although i had oil on the threads of #3, and the ceramic was cracked on #4 when i finally got the wire off.

Tried testing compression but was getting inconsistent results... sometimes 150, sometimes 200 on the same cylinder, might need a new gauge.

i'm leaning towards the motronic box, although that might just be my distrust of engine computers... just hate to drop $300+ on one and still be dead.

Cheers,

...dave

[Scott_]

Not sure of your explanation that you had spark when you turned on the key, but similar to the old breaker point systems, when the key is turned on +12v power is supplied to the coils-- then the -(ground)side is grounded/switched in the motronic controller.

[Medobson1]

I don't think the fan control circuit is the main problem or a contributor at this point. I think that problem is your temp switch or the control relay. If your fuel pump it running then it could be the Hall sensor or the ECU. Since you messed with the ECU Connector, which you shouldn't have. You should examine the connector to make sure you did not bend any pins over or possibly broken a wire in the connector when u disconnected it. The ECU gets the signal from the hall sensor to then fire the ignition. So pull a spark plug and see if it sparks when you hit the starter button. If not then the ignition circuit to the coils is interrupted. Don't forget to ground the plug body away from the cylinder plug hole.

[Medobson1]

Ok you have spark. Now open the gas tank and get an inspection mirror and stick it in to see if the fuel filter is cracked and pumping all the fuel right back into the tank. You can remove the whole gas cap to see this as well. You will see gas shooting out of the filter if it is damaged. This is a common failure on clogged or bad filters. If ok, then you need to install a fuel pressure gage on supply to fuel rack to see if the pump is keeping 35 psi pressure when running.

[Laitch]

If your fuel pump it running then it could be the Hall sensor or the ECU. Since you messed with the ECU Connector, which you shouldn't have.

As far as I'm concerned, the plug is designed to be disconnected so I see no reason to be concerned if you did that, unknownroad.

The motronic is the very last thing to think about replacing at this diagnostic stage.

[unknownroad]

I was initially surprised to see a steady pulsing spark with the key in the "run" position but the engine not turning, but i guess it makes sense.

Aside from the injectors i don't really see the problem being related to fueling, based on the volume of fuel that's being pumped out when i crank it, but i have had some weird performance problems riding the bike in the past when the fuel levels got low, and draining the tank for full inspection will be my next step. After that i guess i'll have to find some way to see if the injectors are firing?

Accursed electromechanical witchcraft...  :oldguy:

[Scott_]

There should be NO pulsing spark of the spark plugs if the motor is not turning.....
The hall sensors tell the ecu to fire the plugs.

Id be checking the wiring for bare spots/grounding to the frame, etc....
The hall sensor wiring is a shielded cable assy so it's less likely to have been damaged, but that isn't saying that a wire couldn't have broke free at the actual sensor though.
Or the signal leads for the coil could be chaffed and grounded somewhere.

[TrueAce]

You may have multiple unrelated events going on here. To start with, how exactly did you attach the charging connector? The sparking without motor turning suggests a direct keyed connection to battery....that's very weird. A low or draining battery suggests the current is being drawn down by something.  As for the fan, have you found any direct switch installed by PO, that could be on causing the continuous running? Check out the interactive wiring diagram in tech, and figure out how those plugs are getting juice before doing anything with other systems. 

[unknownroad]

Well, after far too many distractions like 60-hour work weeks and a death in the family, I finally took another crack at the sitting brick. I dumped the tank, and found a couple of random pieces of rubber sitting inside it rotting away, and a hole in the fuel sock. For funzies, I replaced the injectors with osidetiger pieces, and ran the fuel rail through the ultrasonic for a while since it looked a little crusty inside. Checked all the grounds, traced every wire in sight... everything looks fine.

Hit it with starting fluid and got a backfire that blew the vacuum cap off the #1 cylinder port. (guess i shouldn't have been surprised given the constant spark issue above).

Started going through the troubleshooting list. Hall effect sensors are fine. Despite high hopes of it explaining the constant fan issue (there's no bypass switch installed), the water temp sensor registered a reasonable 2.3k ohms at around 75 'Murican degrees ambient, and the coolant level is fine. Tomorrow i'll bolt everything back together again and take a shot at reading the computer codes now that i found the guide for that.

Any other suggestions if anyone has read this far? i'll check the tank filter for bypass spray, but i was getting so much volume from the pump i'd be surprised to see a problem there. Unless the Motronic (i LOVE that the search function offered me Moronic as an alternate term) codes give me some kind of miracle cure, i'll be hauling it off to the stealership... hate to do that for the first time in 15 years of riding on the bike that i paid the most for, but it's already been the first bike i've had to have towed. I'm not ruling out dragging it to the far end of my property and setting it on fire at this stage, because i don't think i'll ever be able to trust this POS. Typical luck to have paid a more than fair price for a clean, low-mile example of a bike that's supposed to have a good reputation and end up screwed like this.
 :musicboohoo:
To address a few specific responses, the charging connector is a typical fused Battery Tender connector bolted directly to the battery on top of the main leads; I removed it when I began all my troubleshooting on the off chance it caused a problem. The battery went flat because the bike had been sitting for a couple of months for various work and weather reasons. Not sure i've ever had a moto battery still have enough juice to start after more than a couple weeks unless it was on a charger. Disconnecting the ECU shouldn't be a real cause for concern because it's the only way to get to the battery on a K1100RS.

[tsnap]

Please do not give up.  The human always wins!!

There is a huge wealth of knowledge available here and by careful thoughts and acts, you will not only persevere and conquer, but will learn from this encounrter.

Its just a machine, after all!! :usa2:

How about a pix of the ol' girl?

tom

[The Mighty Gryphon]

First thing to do is check that the plug wires are on the correct plugs and coils.  That backfire on #1 sounds like something is crossed.  Remember that the longest wires don't necessarily go to the farthest plug.  The coils should be marked with the cylinders they are coonnected to.

[unknownroad]

Checked and rechecked the plug wires- they're fine.

Pulled the fan relay and determined that it's not stuck, it's just getting a signal to run the fan whenever the ignition is on, even if the bike is cold and not running.
Tried the Motronic fault code display here- http://www.k11og.org/forum/viewtopic.php?t=2110
Grounding pin 1 of the diagnostic block lights up the temp warning light, and it stays on indefinitely without blinking. Got bored after 30 seconds. Also tried the fan test on that page- fan runs continuously regardless of what i do with the pin.

No sign of fuel spraying from the in-tank filter, but it's definitely being pumped through the fuel rail and back into the tank.

Hooked a 12v LED up to the + lead of a couple of the fuel injector plugs. Flashes on for a fraction of a second when the ignition goes to run. Seems to stay lit when the engine is cranked- it might be flickering too fast for me to really register? At any rate, the injectors seem to be the choke point- despite the fuel circulating at a pretty good clip (I don't have a fuel pressure gauge), there's nothing getting to the cylinders. Of course, with the ignition problem, that may be for the best. The lack of accurate compression results concerns me- i'd hate to get the ignition/fuel problems fixed only to discover internal damage.

I noticed that the plug going into the Motronic isn't wired the same way as the one in the Frank Thomas diagram- http://www.oocities.org/fwarner_au/mc_things/K_fuel_injection.html
It's got the same number of pins, but locations 16-18, for example, have no pins. Haven't turned up any other pinout diagrams on Google so far. I'm guessing the 1995 unit is different from the 1993 he outlined, because of course it would be.  :dunno

I'm beat. Wish i had time to part it out.

[TrueAce]

Your conundrum has been on my mind. From your comments, you are a more than average mechanic and show good knowledge of the bike's systems, so whatever is going on it ain't the mechanic's lack of ability. I tried to remember having a situation similar, and recall a couple of times I had strong crank but stumbling attempts to start. Ignoring the other reported symptoms, this must be fuel flow related. My situation occurred after rebuilding the fuel pump.............the pump ran strong, but the intake line and discharge got installed backward, so strong fuel pump function, but nothing in the output line. Another time, there wasn't much fuel in the take, and the fuel pump had come loose as a result of moving it around the shop, off and on the frame, the pump was sending a trickle of fuel cause the intake line wasn't getting the fuel.. Another time the tank output and return lines were connected incorrectly, so no fuel pressure to the fuel pressure regulator. I believe it should be about 65psi to the regulator. Mind you, in all cases , there was spark, crank, and everything checked out, but no start. Be sure you have pressure at the injectors. I believe you are going to figure this glitch out!

[tsnap]

How odd...Last night i WAS THINKING ABOUT THIS BIKE ALSO.  i RE READ THE INITIAL OCURrENCE AND SYMPTOMS, AND THIS CAUGHT MY EYE,

something like, "I drove it for about an hour, then coasted to the side of the road"

I immediately thought, FUEL, water in fuel, which had circulated thru the tank as vibrations mixed it during the ride.  The fuel intake is not all the way to the bottom, so it could have been settled out while parked.  (I recommend a TOTAL fuel replacement, from a CLEAN DRY container, and a CLEAN FLUSH OF ALL LINES, FILTERS, PUMPS.  I have encountered this very very often.


I once flushed the entire fuel system on a kids bike, showed dad the water in the fuel I drained, got paid and left the kid happy.  Kid ran low on gas,  and dad thought he could just pour the good gas off from the glass jar into the tank.  Same job next day!!

 or pressure loss I would find a guage to measure this.

There may be some other problems, low battery, wires worn, or shorted, but this is an easy problem to isolate.

I know from the write up that you have the skills.  Other humans have solved this problem!!  And you have other bikes to ride while working the problem in your head.

Remember, Fuel, Oxygen, Spark.

Because of the initial failure, on the road, I would investigate fuel very thouroughly first.

tom

[tsnap]

When completed, it should look something like this:

Your results may be different.

[TrueAce]

Gorgeous bike.

[Laitch]

Thanks for the ideas so far...

When the battery is fully charged, have you tried starting it with the throttle position sensor disconnected?

[rbm]

Pulled the fan relay and determined that it's not stuck, it's just getting a signal to run the fan whenever the ignition is on, even if the bike is cold and not running.

It's not a good sign that the fan is being commanded by the Motronic to turn on with the ignition.  If we assume that the Motronic is OK, then the water temperature sensor is the source of that command. Yet, you say the temp sensor tests OK.  Did you remove the sensor and test?  Or did you test at the Motronic connector?  If you tested just the sensor, you might miss a short in the wiring that could be fooling the Motronic.

Tried the Motronic fault code display here- http://www.k11og.org/forum/viewtopic.php?t=2110
Grounding pin 1 of the diagnostic block lights up the temp warning light, and it stays on indefinitely without blinking. Got bored after 30 seconds. Also tried the fan test on that page- fan runs continuously regardless of what i do with the pin.

This, to me, is weird.  It should flash at least "1122" or "1133" unless your engine stopped at the right spot.  Are you able to test with a LED instead of depending on the Temp Warning light?  Afterall, your Motronic thinks the engine is overheated so it might be illuminating the OverTemp light by default.   Do you have another Motronic to swap?

Hooked a 12v LED up to the + lead of a couple of the fuel injector plugs. Flashes on for a fraction of a second when the ignition goes to run. Seems to stay lit when the engine is cranked- it might be flickering too fast for me to really register? At any rate, the injectors seem to be the choke point- despite the fuel circulating at a pretty good clip (I don't have a fuel pressure gauge), there's nothing getting to the cylinders. Of course, with the ignition problem, that may be for the best. The lack of accurate compression results concerns me- i'd hate to get the ignition/fuel problems fixed only to discover internal damage.

You have to probe the -ve side of the injectors (Yellow/Grey), not the positive (Green/White).  Still use a +12V LED; still connect the -ve of the LED to ground but connect the +ve to pin 27 of the Motronic.  If you probe the +ve of the injector, it will just remain lit because of the constant 12 volts.

I noticed that the plug going into the Motronic isn't wired the same way as the one in the Frank Thomas diagram- http://www.oocities.org/fwarner_au/mc_things/K_fuel_injection.html
It's got the same number of pins, but locations 16-18, for example, have no pins. Haven't turned up any other pinout diagrams on Google so far. I'm guessing the 1995 unit is different from the 1993 he outlined, because of course it would be.  :dunno

Frank's is a Motronic 2.1 and yours is a Motronic 2.2.  So, the wiring would be different.

Attached are the OEM engine schematics for the 96 K1100 (K589) with Motronic 2.2 to help you troubleshoot. A block diagram for the MA2.2 is here: http://forums.bmwmoa.org/showthread.php?64230-R1100-Motronic-MA-2-2-Functions

[alcorelli]

I am following in earnest, your predicament. I have an R1100R with a similar no start condition.
My K100 however, runs well.
Thank you all for your assistance to this forum member.

Sent from my SM-N910P using Tapatalk

[Vespa no more]

Hang in there. It will run.

My bike too is giving me the bird ... I'm not convinced that the brand new battery is not to blame. Has enough for one start but not two. Car battery will be recruited this weekend.

And once the K100 fires up and CONTNUES to do so... there's a tatty K1100LT waiting for lots of time, too much money and TLC.

Frustrating when you want to be riding. But think of the satisfaction once you get it.

Dare I say it, but have you considered plan Z - getting an expert / auto electrican etc to come around and look at it? there is probably one of the forum near by. If you're like me, it's tantamount to failure - but not if you are on the road.
I'm now going through the Haynes Electrical Manual looking for clues.

Again, good luck

Regards

Guy

[unknownroad]

Pulled the fan relay and determined that it's not stuck, it's just getting a signal to run the fan whenever the ignition is on, even if the bike is cold and not running.

It's not a good sign that the fan is being commanded by the Motronic to turn on with the ignition.  If we assume that the Motronic is OK, then the water temperature sensor is the source of that command. Yet, you say the temp sensor tests OK.  Did you remove the sensor and test?  Or did you test at the Motronic connector?  If you tested just the sensor, you might miss a short in the wiring that could be fooling the Motronic.

I did test the temp sensor at the point where it plugged into the main wiring harness, since I didn't have the appropriate pinout for the Motronic. I examined just about every wiring run I could short of pulling all the wrap off the harness, but it's certainly worth checking.

Tried the Motronic fault code display here- http://www.k11og.org/forum/viewtopic.php?t=2110
Grounding pin 1 of the diagnostic block lights up the temp warning light, and it stays on indefinitely without blinking. Got bored after 30 seconds. Also tried the fan test on that page- fan runs continuously regardless of what i do with the pin.

This, to me, is weird.  It should flash at least "1122" or "1133" unless your engine stopped at the right spot.  Are you able to test with a LED instead of depending on the Temp Warning light?  Afterall, your Motronic thinks the engine is overheated so it might be illuminating the OverTemp light by default.   Do you have another Motronic to swap?

I tried a couple cycles of pulling power from the Motronic for a minute or so to reset it, then cranking the bike, then testing again, always with no results. Even did another ether test to see if that helped (BANG). The over temp light is not lit by default, it only came on when using the test port. I did not try the LED because the instructions didn't make sense from my (sketchy) understanding of electronics; since the source I was reading mentioned that it wasn't needed for K bikes I thought that maybe the test port was wired differently for Ks using the temp light and Rs using the LED. I've got some spare 12v LEDs, though, so I guess there's nothing to lose in trying.

Unfortunately, I have no source for a known good Motronic. Some genius could make a nice living reverse-engineering all the accursed unobtanium '80s and '90s ECMs and porting them to Arduinos or something... $500 on ebay for another 20-year-old part that's "supposed to" work is not my kind of gamble.

Hooked a 12v LED up to the + lead of a couple of the fuel injector plugs. Flashes on for a fraction of a second when the ignition goes to run. Seems to stay lit when the engine is cranked- it might be flickering too fast for me to really register? At any rate, the injectors seem to be the choke point- despite the fuel circulating at a pretty good clip (I don't have a fuel pressure gauge), there's nothing getting to the cylinders. Of course, with the ignition problem, that may be for the best. The lack of accurate compression results concerns me- i'd hate to get the ignition/fuel problems fixed only to discover internal damage.

You have to probe the -ve side of the injectors (Yellow/Grey), not the positive (Green/White).  Still use a +12V LED; still connect the -ve of the LED to ground but connect the +ve to pin 27 of the Motronic.  If you probe the +ve of the injector, it will just remain lit because of the constant 12 volts.

Thanks, I'll give that a shot.

I noticed that the plug going into the Motronic isn't wired the same way as the one in the Frank Thomas diagram- http://www.oocities.org/fwarner_au/mc_things/K_fuel_injection.html
It's got the same number of pins, but locations 16-18, for example, have no pins. Haven't turned up any other pinout diagrams on Google so far. I'm guessing the 1995 unit is different from the 1993 he outlined, because of course it would be.  :dunno

Frank's is a Motronic 2.1 and yours is a Motronic 2.2.  So, the wiring would be different.

Attached are the OEM engine schematics for the 96 K1100 (K589) with Motronic 2.2 to help you troubleshoot. A block diagram for the MA2.2 is here: http://forums.bmwmoa.org/showthread.php?64230-R1100-Motronic-MA-2-2-Functions

Thanks, i'm going to need to fire up another brain cell to put these into practice, but hopefully this will help answer some questions. I appreciate your detailed response!

Thanks to all who have given suggestions so far... FWIW I dumped all the fuel that was in the tank and fuel system and just gave it 2 gallons of fresh 93 octane for troubleshooting, and the fuel lines are connected the same way they were when the bike was running. I don't know anyone I can trust to troubleshoot the bike in person; there's one BMW shop in my area (Champion Honda of North Charleston, SC), and they're my last resort because I have consistently bad experiences with mechanics.

Now that I've got some more avenues to try I'll be able to put that off a little longer... Hopefully this weekend I'll get some time to work on the bike again.

...dave