Intermittent Engine Cutout

[jamesbruce]

Until two Sundays ago, my 94 K1100RS went like the wind. On my way back into town after a breakfast run, she stalled in the left turn lane. Getting out of traffic, she started right up after about 3 minutes, got about a mile, and died. Since then it's a pattern. Go five miles, stall, cool down and go less than a mile, stall again, etc. When it stalls it quits! No sputter, hesitation, quits. When it sets for a while, it's good to go for fine or so miles. When it starts again, good as new for the stated time/distance/heat generation. Sound familiar? 4 months on the plugs, 8 on the fuel filter. Gas tank venting is intact. Good gas. Correctly connected computer. Frustrated rider.

[PacWestGS]

Carbs or FI?

Might have some microscopic contaminate blockng the fuel inlet/bowl.

I had a problem on my Kawasaki once where the vacume tube on the 'vacume actuated petcock' stuck, did about the same thing, found the leaky tube and solved the problem

Good Luck

[jdiaz]

Might be the Hall sensor under the cam chain cover. Remove the fairing lowers, and the little T-shaped cover on the front of the cam chain cover, to reveal the Hall sensor mounting plate. Start the bike and point a hair dryer (on high setting) at the mounting plate. If the bike craps out after five minutes of hot air, you may have found your culprit.

If that doesn't work, leave the fairing panels off so we can progress to the next free checkpoint. :laugh

[jamesbruce]

That's what I feared! I'll check on it. by the way, is that a piece that can be repaired, or is it a swap out?

[jamesbruce]

Thanks for your reply - another lead!

[jdiaz]

by the way, is that a piece that can be repaired, or is it a swap out?
There's probably a repair article on it somewhere. BMWMick has spoken about it before IIRC.

[roy]

That's what I feared! I'll check on it. by the way, is that a piece that can be repaired, or is it a swap out?


I have not had to replace one of these yet...

From memory I believe if you are good with electronics and a soldering iron they can be repaired. Don't recall where I seen an article on this though. With luck one of the seasoned veterans can point you in the right direction.

Good luck

[PacWestGS]

Hall Sensor inspection and replacement was just written up in the ON about three or four months ago.

It was a pretty decent article if I remember.

[kioolt]

It may be worth a try to reseat the Hall sensor plug. Also, I believe that if the Hall sensor fails your tach needle will not wiggle when you are trying to start the bike. Is your fuel pump running when it quits?

[bmwmick]

Until two Sundays ago, my 94 K1100RS went like the wind. On my way back into town after a breakfast run, she stalled in the left turn lane. Getting out of traffic, she started right up after about 3 minutes, got about a mile, and died. Since then it's a pattern. Go five miles, stall, cool down and go less than a mile, stall again, etc. When it stalls it quits! No sputter, hesitation, quits. When it sets for a while, it's good to go for fine or so miles. When it starts again, good as new for the stated time/distance/heat generation. Sound familiar? 4 months on the plugs, 8 on the fuel filter. Gas tank venting is intact. Good gas. Correctly connected computer. Frustrated rider.

James,
Sure sounds like a dying Hall Effect Sensor . You may want to rig up a test light you can see while riding to ensure that you still have 12V at the Motronic relay and/or the coil primary connections when it dies. Since it seems to require a cool-down cycle to 'fix' it temporarily, I'd rule out the ignition switch.
Like Jon said, if you can run without the T-Cover for a while, get a can of "Freeze" at any electronics store to carry with you. When it fails, direct a spray right at the HES plate and see if it starts immediately, if so, you need to either rebuild it or buy a new/used one.
Have you done the 'heat' test? If you prove that it's the HES you 'can' replace the individual sensors for about $12.50 each.
I get mine from Newark Electronics: http://www.newarkinone.com
Dana Hager has a great set of instructions for repairing the Oilheads
HES's and the K-bike is almost identical. Only big difference is
that the K-Bike uses a molded plug. http://users.rcn.com/dehager/
Here is a pic of the K-Bike pinouts for the HES connector.
http://www.bmwmoa.org/forum/attachment.php?attachmentid=2605&stc=1
So a search on "stalling problem" and you should find more data,
http://www.bmwmoa.org/forum/showthread.php?t=3526&highlight=stalling+problem

[jamesbruce]

:banghead Using a heat gun that generated lots of heat, 15 minutes of blasting away had no effect on igition! I became concerned about the insulation of the electrical wires in all that dry heat.

[CustomSarge]

In my case, the main engine computer connector was DRY. A light spray of both sides in WD40 brought it back. G.H. <<<)))

[lorazepam]

:wave
Hey Sarge

[jamesbruce]

After blowing hot are on Hall Effect Sensor and treating the computer connections with contact stuff, I had a nice ride into the countryside and experienced a repeat of the pattern. It appears to stall when going slow, as approaching a stopsign. The lower fairing is still off....-More tomorrow I'll check the HES connections and get some "freeze."

Paul Glaves wrote a dynamite article for Owner's News - April 05. Thanks, SFDOC.

[jamesbruce]

It may be worth a try to reseat the Hall sensor plug. Also, I believe that if the Hall sensor fails your tach needle will not wiggle when you are trying to start the bike. Is your fuel pump running when it quits?
Where is the hall sensor plug? Under the HES cover? or under the gas tank?

Also, how can I tell if the fuel pump is still running?

[Colt03]

Have you tried reading the fault codes stored in the Motronic ?

there are instructions and a fault table on the IBMWR site.

When my K1100lt did that, it ended up being the water temperature sending unit was bad.

Good Luck.

[bmwmick]

Where is the hall sensor plug? Under the HES cover? or under the gas tank?

Also, how can I tell if the fuel pump is still running?

1. Right front corner under the fuel tank on mine. Round connector.

2. The best way would be to plumb a pressure gauge in the supply line. OR you could listen to it with the fuel cap open.

[jamesbruce]

It may be worth a try to reseat the Hall sensor plug. Also, I believe that if the Hall sensor fails your tach needle will not wiggle when you are trying to start the bike. Is your fuel pump running when it quits?
I've reseated the Hall Sensor plug and am about to go on a hopefuly test ride. Yes, the tach needle wiggles while running the starter during a stall. About the fuel pump, is your question about during a stall? :bolt

[cjack]

I've reseated the Hall Sensor plug and am about to go on a hopefuly test ride. Yes, the tach needle wiggles while running the starter during a stall. About the fuel pump, is your question about during a stall? :bolt

Wasn't my question, but yes during a stall. You should be able to hear it run for about a second when pressing the starter button. I think. I get confused with the variations of the pump running when turning on the ignition (the oil heads and the K1200RSes) versus when you press the starter button (the early K bikes). Anyway, you should hear it run either/or.

[jamesbruce]

Near the end of my test ride yesterday, coasted into Big Twin BMW here in Boise and Larry had a chance to look at it stalled. The fuel pump is good. Today, I swapped out the Motronic with a friend who also rides a K11RS and Figured at $1000+ I'd most likely found my answer. Ten slab miles, turned off toward what I expected to be a nice desert route back home, to stall! Turned around and hi-tailed it back home - no stall until I was cruising in first around my neigborhood - stalled and I coasted into my hanger. So... not the Hall, not the fuel pump, not the computer. The tack hand jumps when stalled and running the starter. Process of elimination. I'll review the posts in this thread and start over - vacuum, relay seat, thanks so far. Feel free to jump in.

[jamesbruce]

While still pretty warm from my most recent return, I let the beast idle to check whether the fan would come on (someone asked). The gauge went up to 3/4 , the fan came one (x2) and cooled down (x2). The third warm-up got into the lower red zone without a fan.

BMWMick, the test light idea is interesting. Where to hook it? Does the "freeze" test still appeal?

[Ridealot]

When is the last time you changed the fuel filter. The one time mine plugged the bike would run for a few minutes then die. It would then restart, run a couple minutes and die again. If you haven't changed it for awhile it's something else to check.

[bmwmick]

While still pretty warm from my most recent return, I let the beast idle to check whether the fan would come on (someone asked). The gauge went up to 3/4 , the fan came one (x2) and cooled down (x2). The third warm-up got into the lower red zone without a fan.

BMWMick, the test light idea is interesting. Where to hook it? Does the "freeze" test still appeal?

James,
It still appeals to me......I'm not convinced you don't have a dying HES.
As for the fuel pump running, you have MA2.2 Motronics. You should hear the fuel pump run for about 1.5 seconds each time you turn on the ignition. The older K-Bikes (Prior to Motronic DME engine control) had a different arrangement.

You never said, how many miles on this bike? The TPS can fail in some weird modes but it usually fails in the same range where it is used the most, NOT at idle.

[tjtraver]

This sounds identical to the symptoms I had on my K75 , which turned out the by intermittent HES sensor . I purchased a used one for $100 which fixed the problem (and I figured at worst , it was a cheap diagnostic and good spare to have ) .

I never did the heat gun test , but a "diagnostic" that I used , when mine started to go intermittant , was to ride the bike with the T shaped Hall cover off ( to keep HES much cooler ). Incidents of failure immediately cut in half ( but never went away entirely ).

Good luck with it ... Keep us posted on your progress .

Todd

[jamesbruce]

Put in a temp sensor, and while I had it on a jack, swapped out the tire (and brake disk bushings, installed motolits, and have had just one test ride since. All seems to be working great! True, the weather is cooled off. My confidence is high because previous patterns of stalling were extremely consistent, and non-existant on my test drive.

Thanks to you that responded.

[Colt03]

James,

let us know if it is the water temp sensor, If so then this is at least 3 bikes I know of.

Hope it all works..

[bmwmick]

Put in a temp sensor, and while I had it on a jack, swapped out the tire (and brake disk bushings, installed motolits, and have had just one test ride since. All seems to be working great! True, the weather is cooled off. My confidence is high because previous patterns of stalling were extremely consistent, and non-existant on my test drive.

Thanks to you that responded.

That's really good news James.
Did you ever read out the fault codes from the Motronic during your diagnostics? That should have stored a fault code if the sensor was dead but I'm not sure it would catch an intermittent one. Here are the fault codes.

Code Fault
1133 Hall effect - no signal
1122 Hall effect - no signal
1223 Water Temperature
1224 Air Temperature
1215 Throttle Position Sensor
1111 CO2 pot
4444 No Fault
0000 No Fault
3333 Not a fault - a fan test and memory erasure.

[jamesbruce]

I've printed the fault codes out and am taking her in tomorrow for a seal replacement - will take them in. Someone earlier in the thread said a fault code reader could be easily devised. What's the story on that?

James

[bmwmick]

I've printed the fault codes out and am taking her in tomorrow for a seal replacement - will take them in. Someone earlier in the thread said a fault code reader could be easily devised. What's the story on that?

James

James,
There are a couple of ways. One would be to use a 12V LED you purchased at radio shack OR use this procedure from frank Warner
:
There is a blue 3 way connector on the left side of the bike near the battery, you'll need to remove the side cover to gain access. Turn on the ignition and then shorting the number 1 pin on this connector to earth for 5 seconds, then the temperature light near the tachometer will flash. The light will light for about 2.5 seconds, then a give a number of short flashes, count these short flashes. This count is for the first number, if this is a 1 then you have a fault. Another 2.5 seconds of light follows the first count, then follows the second count and this is repeated for the third and fourth count. This repeats until you turn off the ignition, or reshort the pin 1 to earth for 5 seconds to get the next fault.

http://www.geocities.com/fwarner_au/mc_things/K_fuel_injection.html

[jamesbruce]

James,
There are a couple of ways. One would be to use a 12V LED you purchased at radio shack OR use this procedure from frank Warner
[/url]
Get to Arizona now and then myself. Here's a link to my most recent AZ trip. Taken by a vacationing Phoenix Motorcycle Sgt.

http://www.bmwmoa.org/forum/showthread.php?p=93834&posted=1#post93834