another ignition coil problem

[toolinalong]

hey, this has not been my best riding season,

Some of you may be aware that I have had some major problems with the bike this summer, having spent almost $5k to replace a wiring harness, throttle bodies, and then finally an ECU, which was no doubt damaged by the catastrophic short circuit that occurred. Here is the latest installment on my 2002 Single-Spark, R1150RA with 89000 on the clock.....

So I finally get the bike back from the Denver dealer after 3 weeks, and it's running real good, so I decide the best thing to do for my mental health before school starts on the 24th is to go for a 4-5 day ride over to Utah. Once I hit the road though I decide to head for northern New Mexico first, then head over thru the northern part of the state to AZ for a bit, then come up through UT and back home.

So it's day two, and it's about 3pm. I have just turned off of Highway 96 onto Highway 550 heading north, after wandering around thru the mountains around Taos, down to Espanol, then back up to the Abiquiu Reservoir. I am now about midway between Albuquerque and Bloomfield, when suddenly the bike shuts off. dead.

About 45 minutes go by, with lots of traffic whizzing by me just a few feet away (busy 4-lane highway with a lot of truck traffic and a 6 ft wide shoulder, when a Good Samaritan with a GS in the back of his pickup stops. By that time I have changed out all the fuses (just to be 100 percent sure about that) and checked for spark and fuel, and everything seems fine, except it won't start. My cell phone has no signal but his does, and we call the service manager at Sandia BMW in Albuquerque, who gives me the number of the Motorcycle Taxi Service, owned by one Tim Jones (TJ), who we call and he says he can come get me. Says he can be up to my location in about 2 hours, and the cost is very reasonable at $171. So the Good Samaritan says so long, and I prepare to hang out and wait. Of course I can't not continue to check for other electrical problems, and after wiggling some wires and looking at what I can, I hit the starter button, and lo it starts!

So I hop on and ride up a mile or so to the Apache Nugget Casino, the only building I have seen since turning onto the 550 highway from the 96 road some ten miles back, and I pull in, go inside and ask to use the phone. I call TJ and ask to cancel the tow, and fortunately he has not left town yet. I get on the bike and head north. About 4 miles up it quits again. I get off, and this time I pull the tank and start looking for stuff under there. It starts to sprinkle, and there are rain showers to the west, heading very slowly my way. It is, somewhat fortunately, an atypical day, with lots of cloud cover and scattered thunderstorms and rain all over the area, and very cool, rather then hot and sunny....

After about 1/2 hour or so, just about when I realize I am not going to find the problem, Good Samaritan #2 stops by, this time a Vietnam Vet from Cortez Colorado on his way home from a rally with a HD in the back of his pickup. He offers tools, and I say, if you can just wait a few minutes I will put the tank back on, and could you please give me a ride back to the Casino? He does and and I call TJ again, and he says ok he will leave Albuquerque in 20 minutes or so. It's now around 5:30 pm.

He arrives around 7:30, and we get the bike loaded up into his covered trailer just as the rain hits in earnest, but just for fun I hit the starter just before we push it up the ramp and of course it starts right up. He gets this funny look on his face, and I say don't worry, we are going to haul it back to town, and 2 hours later we arrive in the north part of the city, where he drops me and the bike at the Nativo Lodge, a former Howard Johnson's located on I-25 and located about 3/4 mile from the Sandia BMW dealer.

The next morning I call John the service manager, and after talking for a bit, he says he will try to work me into his busy schedule. I go down to the bike, wipe off the previous night's rain, get on, and it starts right up. I ride it over to the dealer and check it in, and John says he thinks he can look at starting around 11:30am.

At 4pm Friday someone else at the dealer, not John, calls and says it is the ignition coil that is bad. inexpensive item, only about $110. But they don't have one (of course) and it is too late to get it shipped today. Earliest it might be able to get there is Tuesday, which means I probably ride out on Wednesday.

I have meetings at work I cannot miss this coming week on T,W,Th,F. So, Southwest Airlines, $200 RTrip, and I get home last night at about 7pm.
Next Friday I fly back in the evening, pick up the bike on Saturday morning, and cross my fingers nothing else happens as I head home on I-25, with my classes beginning on Monday.

total dollar cost on this one, somewhere north of $1,000, depending on the the bill from the dealer in Albuquerque.

total cost in terms of my mental health, unknowable exactly, but considerable....

Now I don't want to jinx this whole thing yet again, but I did the same test on the coil that I assume they did, checking the resistance of both primary and secondary windings, before taking it into the Denver dealer a month ago, and my test showed it was ok. Also I have ridden the bike over 2000 miles since the wiring harness mishap, including 700 miles in the 2 days before this latest problem happened. Also, when I was trying to troubleshoot it by the side of the road the day before, both times I tried it I was getting a good healthy spark and yet it would not start. So forgive me if I am a bit skeptical of their diagnosis.

I have read all the recent posts on Sumbeemer's no start problem, and I must admit I am a bit confused. John the service manager at Sandia said that BMW coils (not others) have a tendency to stop working when they get hot. Well it wasn't that hot out at the time of the failure, certainly the bike has been running hotter on many occasions. When I mentioned to John that by the side of the road I was getting an obvious strong spark and no start, he said he had no clue about that, but that his tech had tested the coil and found it bad.

Can anyone shed any light on this situation? I am especially confused as to whether the process of pulling the plug to check for spark in itself can damage the coil.....

Or if anyone has an experience with any other intermittent no starts...

Thanks,

Bob




B

[boxermania]

toolinalong

First and foremost I have to praise your perseverance and disposition.......I don't think I would be rational after all you have endured, but I digress.

Typical coils fail or become intermitent as they are exposed to many heat cycles as the isulation starts cracking. I will have to assume that with the mileage on the bike and in New Mexico the coil became intermitent as it heated up, that's why it would start after it had the chance to cool down.

I hope that you are past this experience and have many more enjoyable trips.

[Sunbeemer]

Sorry to hear about your troubles, and hope they are only minor...Since the tech was able to test the coil as bad, that's a good place to start and not too expensive to replace. I'd test it again when you get it back, even put it in a low oven to heat it up and retesting it if it initially tests ok, just to confirm that it is the culprit.
Also, I carry a spare set of plugs with me, and I know how to use 'em!

I see about about only other ignition part you haven't replaced is the Hall Effect sensor unit and/or the wiring harness for it. These also have a history of failure, usually when they get wet or hot, sometimes accompanied by widely swinging tachs.
They can be tested with a little rig you can make out of an old LED, a 1000 ohm resistor and a 9V battery as described here:
http://users.rcn.com/dehager/
...click on the article called, "BMW Oilhead Hall Effect Ignition Impulse Sending Unit (1,354 KB .pdf)
http://users.rcn.com/dehager/service/oi ... ensors.pdf

Or you can do a simple operational test by turning the key on and slowly rolling the engine over by hand and you should hear the fuel pump come on at TDC (and at BDC) indicating the Hall sensor is signalling the ECU when to fire the plugs.

[toolinalong]

Thanks Gentlemen.

Both dealers claim to have checked the Hall sensor as part of their investigations, so I will cross my fingers for now on that one.

And Sunbeemer, actually there are a number of things besides that that could be replaced before I am able to rule out future problems: ignition switch, right and left handlebar switchgear assembly, heated grips,clutch switch, side stand switch, O2 sensors, probably one or two other things, any of which could strand me again......

Now what was Rob saying about that CANbus doohickey........?

[Sunbeemer]

Oh..you mean "dead", as in no dash lights, no fuel pump whine on key-on, nothing?

[sweatmark]

toolin-

Sorry to read about the travel time moto woes. Hope the fix is simple and provides assurance of future problem-free riding.

When time permits, I'm going to hotwire the sidestand switch to eliminate the possibility of component failure and getting stranded in Timbuktu. Similarly, I wish we had simple means of checking circuit continuity for the handlebar controls. And finally, I'm very tempted to attempt a dual- to single-spark conversion (or at minimum convert the stick coils to remote under-tank coil) to eliminate that particular R1150R weak link.

Until the F1200R is available (wishful thinking), my Rockster will get all the peremptory fixes possible to maintain its usefulness.

Hoping that you get the usefulness you expect from your bike, especially after the harness fix.

[toolinalong]

I like that idea a lot. Don't know why exactly but that sidestand switch is starting to make me nervous. Let me know what you know about how you might be thinking about doing it....."hotwire?"

[Biff's R]

Just a random thought.

If you have a spark problem, start at the cheapest part, and then work backwards. Plug, then wire, and then coil. I learned this the hard way.

[toolinalong]

Interesting.

I just called John at Sandia BMW to check on how my ignition coil replacement was going as I have a flight booked down to Albequerque this evening to go and pick it up.

He says it turns out it was the Hall Sensor, the coil is actually ok. And they are just now putting it back together, and then they will do a test ride with it.

Glad I didn't decide to hang around and wait for them to get that coil they said would arrive on Tuesday.......

bobindenver

[toolinalong]

Done.
I got home last night after riding a bit less then 9 hours from Albuquerque. I went thru Santa Fe and up on US 285 to home, a distance of 432 miles.
The ride duplicated the last leg of one that I had taken back in May of 2002, when I did a ride to the north rim of the Grand Canyon and back just after having completed the 600 mile break in service.

It was in fact the Hall sensor, not the coil. As it is generally recognized as a "wear" item and the bike has 89000 on it, it is not unexpected.
I went ahead a purchased the coil from them anyways, and will replace that and the plug wires before next season as a PM thing.

One nice thing, Sandia BMW (John, Service Manager, and Ben, BMW Master Tech #517) only charged me 2 hours labor for the whole job, and that included all the initial testing, the replacement, and the test riding they did after the repair. I left town yesterday morning feeling confident I would make it home without further problems, and that was priceless.

Bob

[Sunbeemer]

Glad you got that sorted out and got home without further incidents. Now you should be good to go another 89K miles!

I'm curious if your Hall Sensors were really bad, or if it was a wiring harness failure?
I've read that problems with Hall sensors are not usually with the sensors themselves, but the wiring harness that attaches them to the Motronic computer, especially where it passes under the clamp that secures it behind the alternator belt. The insulation of the individual wires in the harness there deteriorate and the wires short together. And this is not apparent from looking at the outer jacket, you have to slit it open to inspect them. I'm concerned enough about this wiring failure to rewire the sensor plate using high-temp wire in the future.

I think this has become such a common failure that it is now considered a "wear item", like you said, but it actually results from bad design. I'm surprised to hear myself say this about a BMW; maybe the insulation would last forever in colder climates, like the Bavarian Alps?

As for hotwiring the sidestand switch, I have heard of so few of these failures by comparison, I'm going to leave it alone and focus on rewiring the Hall Sensor. Don't forget that the sidestand SAFETY switch is a safety item - one that has probably saved my butt a time or two. Just saying!