04 R1100S runs rough when warm

[6e0ff]

I have an 04 R1100S with twin plugs. The bike had been sitting because I was overseas for a while. The battery was dead as a doornail and wouldn't take a charge anymore, so I did all the stuff to replace the battery. I unbolted the tank and lifted it up, but did not remove it all the way. Since then, the bike is running rough sometimes. It will seem fine, but then start misfiring to the point where sit won't stay running sometimes and I can't give it any throttle. It seems to happen more once the bike warms up. It left me stranded about 15 miles from home last week. Since, then, I've been riding it around the neighborhood to try to make it happen again, and after letting warm up in the garage and driving in circles around the neighborhood with the plastic off the bike for 5 or 6 miles (my neighbors must hate me) it started not idling and misfiring again. I was able to baby it home this time at least because I was close.

I've checked the air filter to make sure it didn't have mice in it or something. The bit of reading that I have done indicates that someone the throttle cables get knocked out of alignment when the tanks is moved about. Bad gas in the tank from sitting and need to replace the fuel filter? I am dreading taking the tank all the way off and taking the pump/filter assembly out, but I am willing to do it if need be. Anything else that I should check before I pull the tank?

Edit: I plan to sell the bike after I get it running right. Anyone want to buy it now? I'll make you a good deal (within reason.)

[brentw1]

probably bumped one of the throttle cables out of the socket on the throttle bodies.
or my favorite bad coils, after sitting could be any one of several things.

[SergioK]

Yes, check the throttle cable sheaths where they end at the TBs. Ensure they are seated properly.

[6e0ff]

Just checked the throttle cables where they sit in the TB. They look correct to me. What's next? Fuel filter? I also read a bit about the Hall sensor potentially being an issue. I suppose I should pull the plugs and see how they look and then go from there.

[6e0ff]

Just to be sure I'm not doing something dumb, here are a couple of pics. I tried wiggling everything and nothing seemed loose.

Right cable


Left cable

[tm1100s]

Is the procedure for a battery replacement or disconnect to turn the key ON and cycle the throttle from closed to wide open then closed again still in effect or has that been decided not to matter? I seemed to have some hard starting issues after forgetting to do this.

[mtgill]

I have just recently experienced, and resolved the very same issue.
Bike ran great while cold, but after a long run on the highway or stuck in traffic, it ran rough (bordering on stalling). Embarrassing how rough it was... Milwaukee iron rough!

Did a test on Friday, checking to see if one of the stick coils was shot... pulled the electrical connector from each stick coil to see it's effect on operation.

While the bike was running rough...
LHS cylinder stick coil disconnected... noticeable change in bike operation (bike ran REALLY rough).
RHS cylinder stick coil disconnected... no change in rough bike operation. Suspecting the RHS stick coil, I pulled it out, installed a spare plug, a checked it for spark. First test... no spark. Second test... spark.

So now I'm suspicious of the stick coil. Reinstall the stick coil, and the bike runs fine.

While fiddling with the connector on the stick coil, the bike runs rough.

Pull on the connector (but not disconnect)... bike runs rough.
Push on the connector... bike runs good.

I disassembled the connector and found the very fine pins within had broken within the connector.

When pushing the connector closed, all of the pins made contact and the stick coil operated correctly.

When pulling on the connector, the pins lost contact and the bike ran rough.

I suspect that the plastic connector housing is growing with heat... when the bike is cold, the connectors are in contact enough to run properly. As the bike heats up, the connector is "growing" losing contact and causing the bike to run rough.

I did some fancy soldering on the connector (because I can't get a replacement connector from the local dealer for three weeks), and the bike seems to be running as its supposed to.

I don't know what happened to the connector, but obviously it's been damaged at some point in time. Seems to be OK now.

Just my two cents...

Mike

[6e0ff]

I saw it reported one place, that the throttle reset thing after battery replacement, doesn't apply for my bike, but I may do it anyway, since I have the plastic off and relatively easy access to the battery.

It feels more like a spark issue to me than a fueling issue, since when it runs rough, it kind of pops and almost backfires on occasion. I'll dig in the the coils when I get home tonight. This also lets me put off pulling the tank.

[6e0ff]

I disconnected the battery and reconnected it and then did the key on throttle back and forth thing. No change.

I pulled the stick coils and the checked the connectors and nothing looked out of place. Pulled the coils and removed the plugs and nothing seemed obviously wrong there either. After doing more reading about folks with similar symptoms, I decided to bite the bullet and order new stick coils and plugs too while I'm at it.

[Sideshow_S]

OK, your cables look well seated, and I was ready to put money on that before you posted the pics.

Consider this -- the problems started after you did maintenance, which, as you stated, involved tilting the tank up.

I have had gas problems from a bike sitting too long. In fact, the ethanol gas we have here ate the rubber boots that mount the fuel pump rubber isolator rings, turning them into a bunch of bits of rubber that clogged the fuel intake sock.

Tipping the tank up puts all the gunk on the one side of the tank. I'm guessing you either have the bits-o-rubber thing I had, or your fuel filter just picked up a lot of gunk and it's clogged.

I had the same symptoms as you. I could go 10 miles and then all of a sudden I couldn't do over 60mph and it was knocking like mad. The next ride was fine (not that I knew it, but the rubber bits had settled out of the fuel pump pickup sock) and I made it 5 miles before problems occured. This time it was rapid, jerky accelleration/decelleration to the point that I felt like it was going to buck me off like a 5-second bull.

The rubber bits from the fuel pump isolators were taking over the pickup sock -- clogging, unclogging, clogging, unlcogging to get enough/not-enough pressure to actuate the fuel injectors properly.

I expect you have a similar issue. Mine came from gas sitting in the tank over 2 years (as it was animal-damaged and I watched ebay for all the parts I needed).

[Chris Canning]

Start from scratch take the tank off,there's another thread on here about such some people seemed to be frightened to death about taking it off when it's just a case of disconnecting the electrics pinch the fuel pipes and prise them off and lift the tank.

The fuel pickup is well off the bottom of the tank if you have never had the filter out you'll be amazed at the amount of c**p and water in there put a new filter in the right direction!!,again folk think it's difficult it's easy fitting it back in the tank can be a hassle because it has to be in a certain position the golden rule 'Don't force it' in the correct position it'll just drop straight in,at least then you have ticked another thing off the list that it might be.

[6e0ff]

I have various parts coming in the mail that won't arrive for another couple days, so I will probably fully drain and pull the tank tonight.

[Groceryrun]

mtgill :

That primary ignition coil connector. Would you know if it's part number six,
83 300 402 341, under Electrical System ?
If you get one from the dealer can you get back to us with the part number ?

[mtgill]

I have part # 8 from the engine electrics micro-fiche on order:
08 Repair kit, wiring harness 1 61127685348

Looks like it is the connector with a pig-tail of wires. Will confirm the contents once the package arrives.

Just an FYI... BMW uses a LOT of connectors in common between the cars and bikes. I was in an auto-wrecker over the weekend, and came across a mid-late 90s 328i that was totaled. Spent 10 minutes stripping every electrical connector I could from it. I now have a pile of spare connectors, with pins. My dad damaged the connector to his 1200GS ABS unit... happens to be the same connector on a Z3 or Z4 ABS unit.

[Groceryrun]

Thanks.
I was hoping to just find a source for the connector itself without the wires -
at a lower cost than the cost for the connector repair kit.

[6e0ff]

I pulled and drained the tank last night and managed not to pour gas over the entire floor of my garage (only half). There was indeed quite a bit of crap floating around in there, broken bits of rubber and other junk. The fuel filter looks fine visually, but the hose connecting the pump to the filter was starting to decompose a bit (hence the rubber bits). It will be a few days before the new filter and hose arrive in the mail, so there isn't much else to do in the interim. I'll prime the filter with new gas and get it all back together and see how the bike runs before I do anything to the stick coils. If it still runs like crap, then on to spark related issues.

[pwillikers]

The stick coils are very common failures and easy to diagnose. Do that ASAP.

[Groceryrun]

6e0ff:

Does the old fuel filter seem clogged ?
I know you're getting a new one, so maybe you might open up the old one.

[Sideshow_S]

No need to open up the filter -- just blow through it. You'll probably know right away if there's too much restriction.

I haven't had any issues with priming when changing a fuel filter. After assembling everything, I usually just cycle the ignition key a few times to prime the pump and hear it cycle. You can usually hear it push the air through and quiet up.

If you were used to riding it (rather than just getting back to it from being overseas), you'd probably notice the fuel pump running quieter, too. That whining fuel pump noise is those things that can creep up on you over time and not notice. My '99 has the best tell-tale fuel pump, getting noisy when I'm on the last 1/2 gallon of gas, and getting whiny when the filter needs changing.

[6e0ff]

I didn't get a chance to look at the filter last night, but I will this evening. I may cut it open just because I am curious, but I'll try blowing through it first to see how it is.