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Cold start - a little rough


kalali

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A long time rider but a Boxer newbie and a perfectionist with a question. Subject is a 1999 R1100R with 16K miles. Only owned the bike for a month and 300 miles. The cold start is always a little choppy with the fast idle pulled. Takes a couple of tries to get the bike started to maintain idle,runs up to 1200RPM for a couple of seconds, drops to 1000RPM, a little choppy, a little push on the fast idle knob brings the idle back up to around 1500RPM, a little choppy and finally steadies out, slowly move the fast idle down to 0 and idle smoothest out. Process takes around 2 minutes and only during the first start in the morning. After that the engine runs fine with a steady idle spot on 1000RPM the rest of the day. Plugs are new Autolites, I replaced myself and I have ordered a set of new spark wires since they are original according to the PO. All other maintenance items are up to date. I have owned bikes before, even FI bikes that were "cold blooded" by nature and I can live with that but rather rule out obvious causes before resorting to that explanation. I was thinking about cleaning the intake tract, e.g., remove the brass screw and clean out the hole, pull back the intake boot and clean the throttle plate, etc., but not sure where else to look. So, what do you folks recommend as next steps? Hopefully something simple I'm overlooking.

Thanks as always for helping us newbies climb this steep learning curve.

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Evening kalali

 

What are you running for a CCP? (incorrect CCP can have an effect on cold start idle quality)

 

If OK in the CCP department then make sure the Intake Air Temp sensor (in the air cleaner top) is plugged in & that the terminals in the connector are making good contact with the pins in the sensor.

 

Is your bike using any type of fueling modifier like a Techlusion or a Fuel Nanny?

 

 

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I battled with this for quite sometime. Mine was alot worse than yours. However what has fixed mine is keeping the battery on a trickle charge. If the bike sits for more than one day the clock drains enough along with all other memory and it will get to a point with enough voltage drop to cause the cold start problem. I will make the assumption that after this cold start gyration that the bike acts normal, is this correct? I have pulled my hair out trying to figure this out.

 

The problem with this vintage of bike, when you turn the key on it does a bite check of the ABS system. Then you push the start button and more voltage drop because of the high demand of the starter, now when sitting and not on the charger this causes a cold start mystery.

 

On my rig '96 R1100R I started to notice more and more faulting of the ABS system after engine start. So with research I found that my battery was installed in '09. When I replaced the battery the first cold start was magnificent. I took the bike on a 2k trip and it was flawless for the whole trip. When I came home I let the bike sit for 3 days without trickle charge, it then started like crap. Put it back on the trickle charge and all is well. The problem with this is once started you need to drive it far enough to recharge the barly depleted battery.

 

Now with this issue once the bike is started and driven it works great after that.

 

The bike can sit for at least a month, and will still start but with the rough start always. There has never been a time that it would not start but enough voltage drop to cause the cold start issues.

 

I hope this will explain it to you. And I am sure there will be plenty of opinions on this but for me this is what works. I have had this issue as long as I have owned the bike (2 years) and now feel good about what causes it. Maynot fix your problem but it has fixed mine. I have spent alot of time reading causes (which are not that many) and still had not come up with any conlusions. The key for me was the constant faulting of the ABS on cold startup and the only thing it could be was battery voltage drop. As I stated, enough to cause problems on cold start. There may be another underlying problem with wire insulation which is a problem with these older bikes, but for now I am satisfied with the results.

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You can read the last post on this page, Slow First Start, or the whole thread. The bottom line is that the Oilhead is voltage sensitive on the first start of the day.

 

As DR suggested get the right coding plug and get the tune right and then go about it systematically. Hopeful some of my experience helps you.

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Whatever else, I like my "warmed-up" idle a little higher than that. The spec is 1050 +/- 50. I like to keep mine around 1200. It comes off idle a little easier for me that way.

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... If the bike sits for more than one day the clock drains enough along with all other memory and it will get to a point with enough voltage drop to cause the cold start problem.

Does your bike have any other parasitic loads (Alarms, dodgy alternator diodes, farkels etc) The standard discharge on these bikes is small and the battery should easily hold enough punch for at least a week of not running it.

Once that engine fires it should be getting plenty of punch from the alternator to keep the ECU happy.

 

 

 

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One of the worst offenders for parasitic drain is the Kisan Signal Minder. It adds 50% to the normal 5 mA drain. If you need to let a bike sit for 2-4 weeks all you need to do is remove fuses 3 & 5. The drain drops to 0.5 mA.

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Thanks as always. One correction, with the fast idle pulled and slightly nudged, the engine speed sits around 2500RPM before I pull back to normal idle. Anyway, the battery is a three month old Westco and I always keep my bikes on a Tender when not ridden, even overnight. I think my idle speed is a tad too low and 1100RPM works better for my bike. All in all, my intuition tells me that the bike needs a good long ride at high engine speed to clean things out. Its just not been ridden enough for this type of drivetrain. In the meantime, I'll see if I can speed up that (cleaning) process.

Roger - Great thread and saw it earlier. My symptoms are after the engine starts and during initial warm up. I have already accepted the wimpy cranking and doesn't bother me as much.

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Morning kalali

 

A lot of 1100's had a little rough running (& even stalling issues) right after an overnight cold start.

 

Most of the, from-cold-start through warm-up, poor running was due to trying to get the surging out of the engine by playing with different CCP's, or different TPS settings.

 

There were even a few BMW service bulletins on the early 1100's that addressed a cold-soak cold start ride away with poor idling, or even stalling after cold start ride-away. (your 99 is on the late side for this but I really don't know when all the Motronic updates were fully implemented on the 1100)

 

As I mentioned above--start with a clean slate. Install the correct factory installed CCP & put the TPS back to factory settings (if it was ever moved--& a lot were). Then see what your cold start cold ride-away acts like.

 

If it still acts up on cold ride away-- Then try things like--

 

_keying on then off about 3 times before starting & riding away.

 

_Removing fuse #5 overnight then re-installing just before starting & riding away.

 

_check R/H spark plug wire for contacting the R/H TB cam ( & wearing through) at idle or just above idle.

 

_try a tankful of non-alcohol gasoline (if you can find any in your area)--sometimes marinas have it if a local gas station doesn't.

 

See if something points a finger for you.

 

The decent cold start but acting up (or even stalling) on first cold ride-away was prevalent in a lot of early 1100 bikes. BMW did an updated Motronic on the later 1100 bikes & even did a warranty Motronic replacement on some early bikes (mainly earlier than yours though).

 

 

 

 

 

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Just finished replacing the spark plug wires with Boneyard aftermarket units. Fortunately not much to remove in the R to access the coil, just had to lift the tank a few inches to give enough room to slide my hand from underneath to pull/push the ends into the coil. Also removed the brass screws while noting the # of turns and cleaned some black residue from the tips and inside the hole. Will take it out for a spin later to see if it helped (or I screwed something up in the process).

Sorry if this obvious but what is CCP? I initially thought it meant cold cranking power but the reference to "factory installed CCP" threw me off a bit. Thanks and will report back after a ride. As for TPS, it appears to be unmolested but I'll look more closely to see if I see any signs of fiddling.

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Just a quick update. Went out for a short ride. Good news is the I didn't screw anything up when replacing the spark plug wires. The not so bad news is cleaning the brass screw and the new plug wires didn't make a difference. I turned out the screws quarter of a turn evenly and that didn't affect the idle speed so I put them back to the original spot. All in all, it's really not that big of a deal. I'll just let the bike warm up for a couple of minutes and ride on. By then the idle speed is just fine.

As for the CCP, it looks like its untouched, as I expected.

I think I'm going to chalk this up as a non-issue for now and just continue to concentrate on my shifting skills and learn about the bike. I'll deal with it next riding season when I'll do a valve adjustment and do a TB balance. Hopefully I'll be able to score a Harmonizer in the meantime. Thanks again.

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Evening Kalali

 

After you ride it for while to get a good baseline on performance & runability try removing your CCP then ride it a few days like that. No CCP will disable the o2 sensor & richen the idle fueling some. That will also probably raise your idle RPM a little.

 

Back in the 1100 era a lot of us removed the CCP on the 1100 bikes to improve engine smoothness in the lower mid range (that puts the fueling more closer to the European open loop mode).

 

The big difference is the European open loop fueling used an idle trim pot to lean the idle back out to meet European idle (only) emissions complience.

 

If you don't like it with the CPP removed then just reinstall it.

 

 

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Great information, thank you. Just as an aside, on my Buell, a few German guys developed a free software that allows you to completely manage the CPU, including the fuel and timing maps across the entire RPM range as a function of the throttle position. It also provides real time data logging so you could tune the FI system perfectly, idle to redline, in any gear. Its perfect for tuning the bike after exhaust/intake upgrades.

Is there anything similar developed for the Motronic 2.2/2.4? If not, how does one tune these bikes on a dyno? With so many of these bikes out there one would expect to see something similar, even at a fee. I'm guessing people probably resort to piggyback methods like PC, etc., which is nowhere as effective as talking directly to the bike's brains.

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Morning Kalali

 

You need to talk to Roger, he has come up with a great add-on o2 sensor feed back fueling modifier.

 

On the BMW 1100 with Motronioc 2.2 there just isn't much available to (chip) the computer. There are/were a couple at one time but they had issues & removing/replacing the chip ruined a few Motronics.

 

I had a few BMW 1100 boxer bikes (both R & RT) & just removing the CCP improved the fueling enough to take most of the surging out (assuming ALL the other engine tuning was just about perfect). That does richen the idle quite a bit (too rich for some riders). An idle trim pot (from European 1100) could then be used to trim the idle fuel leaner. A rich idle never bothered me personally though & the rich idle did improve ride-away & low/mid RPM surging)

 

Some 1100 era riders also used a Fuel Nanny (turned into a Techlusion) to add more mid range fuel & if set properly those did work (but were not easy to set up & adjust properly)

 

A well tuned open loop 1100 ran pretty good but some still had a little off-idle low gear steady throttle surging.

 

So talk to Roger as there are some great reports on fueling improvements.

 

Added: my suggestion is-- before doing anything non-stock in the fueling/tune-up department get that bike RIGHT as far as factory/BMW specs goes.

Get the valves set correctly, get the BBS air passages cleaned out (it sounds like yours might be plugged as you got no change in idle RPM with BBS screw adjustment). Get the TB balanced, get the fuel injectors cleaned out (either by riding with Techron in the fuel or removing & sending out). Get it to run best possible in STOCK FORM. THEN work on aftermarket fueling improvements.

From my past experience, if you try to modify things BEFORE the engine is running it's best in stock form then you create more issues than you solve, as anything not running right then you don't know if it with your add-on set-up or in the original engine controls.

 

The other thing to keep in mind is: the BMW boxer only has 2 very large cylinders so it will never be as smooth running as a 4 cylinder smaller piston engine.

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Kalali, DR has it right, get the bike as near to perfect as you can, in stock form.

 

The 1100s and 1150s, when tuned, all seem to benefit hugely from the addition of 4-8% more fuel, across the map. One of the thing when considering your options to add fuel on an 1100 is the type of fuel you run. Fuel with 10% ethanol means you have to richen the mixture 4% over gasoline. If you have an O2 sensor that happens automatically. Without an O2 sensor you need to add 10% more fuel to end up 6% richer. There are a couple options though that we can discuss when you're ready.

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Gentlemen, thanks for the input and everything you all said absolutely makes sense. I did read up on Roger's great work on the AF-XiED but sort of included that, maybe incorrectly, in the group of piggyback options, a great option nonetheless. You guys are right and I'm nowhere done with bringing this gem of a bike to its original glory and I know I still have a good bit of cleaning to do in the air delivery space. Unfortunately we are pretty much stuck with the crappy ethanol fuel but I've been feeding the engine with a steady dose of Techron so we'll see how that helps. I'll do my best to do most of my learning by going through the archives and keeping good notes. In the meantime, thanks for bearing with all my newbie questions.

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Unfortunately we are pretty much stuck with the crappy ethanol fuel .

 

Afternoon Kalali

 

If you have any lakes or large rivers around you then you might try a boat marina as alcohol gas & watercraft don't mix very well so a lot of marinas carry alcohol free gasoline. Not something that you want to do often but you might get enough alcohol free gasoline to see if the bike runs better on it.

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  • 2 weeks later...

Hi folks. I just wanted to give an update that might provide additional clues and perhaps a different course of action. What I've noticed is at cold start up with the choke pulled to the middle, the bike starts up (sometimes takes a second push of the starter), and the engine speed sits at around 2K RPM and runs nice and smooth for about 10 seconds. Then all of a sudden it begins to drop to 1K and gets a little choppy for about 15-20 seconds and then it slowly climbs back up to 2K and smooths out again. I can then close the choke and get a steady smooth idle at 1K RPM and ride off. Is this pointing to something like the O2 sensor circuit, leaky injector(s), etc.? Bike has only 16K miles. Thanks as always.

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Hi folks. I just wanted to give an update that might provide additional clues and perhaps a different course of action. What I've noticed is at cold start up with the choke pulled to the middle, the bike starts up (sometimes takes a second push of the starter), and the engine speed sits at around 2K RPM and runs nice and smooth for about 10 seconds. Then all of a sudden it begins to drop to 1K and gets a little choppy for about 15-20 seconds and then it slowly climbs back up to 2K and smooths out again. I can then close the choke and get a steady smooth idle at 1K RPM and ride off. Is this pointing to something like the O2 sensor circuit, leaky injector(s), etc.? Bike has only 16K miles. Thanks as always.

 

Afternoon kalali

 

That is a little too early for the o2 sensor to be doing anything yet.

 

 

 

 

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Thank you. That was my thinking as well. I figured it would take longer for the O2 sensor to become active but I'm just wondering what would cause the engine speed drop after a few seconds and then pick right back up after another few seconds. The other thing is the exhaust doesn't smell particularly rich which makes me think the injector(s) are not dripping/leaking post shut down. One thing I know I need to do is a thorough cleaning of the intake tract based on the extent of the soot on the BBS. I actually tried removing the intake boots - remove clamp and slide back into the airbox, but had heck of a time dislodging the boot from the throttle body. I'm going to try it again this weekend and hoping that should address my cold start issues.

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I just wanted to bring back this thread I had started earlier and see if I could some additional help. I've been reading about folks discouraging about in place warm ups - which is what I'm forced to do, and I'm now more determined to address my issue. My issue is during cold starts, with the choke on, the bike starts and runs at around 1800-2000 RPM as it should but then it gets a little choppy and drops by itself to ~1000-1200. Then after another few seconds, it slowly climbs back up to around 2000 RPMs at which point I can close the choke and get a steady 1000RPM idle and ride away. The whole process could take a couple of minutes during which I'm basically sitting still. Warm starts are fine and the bike runs great otherwise. Bike is all stock except for the charcoal canister which I removed.

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What happens when you just start up and ride away? does it bog down?

 

Good question, haven't tried but assumed it would. Maybe I'm too old school but I guess by habit I never just start up and drive away any of my vehicles, cars or bikes alike. I'd like to allow for the oil to get a chance to circulate through the internal moving parts before I push past 2K RPMs. Quite honestly reading the comments about the oil sight glass popping out due to extended warm up periods got me a bit worried. That plus the fact that I think my bike's behavior is just not normal and would like to fix it if I can.

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What happens when you just start up and ride away? does it bog down?

 

Good question, haven't tried but assumed it would. Maybe I'm too old school but I guess by habit I never just start up and drive away any of my vehicles, cars or bikes alike. I'd like to allow for the oil to get a chance to circulate through the internal moving parts before I push past 2K RPMs. Quite honestly reading the comments about the oil sight glass popping out due to extended warm up periods got me a bit worried. That plus the fact that I think my bike's behavior is just not normal and would like to fix it if I can.

 

Also bear in mind that the owners manual specifically states that the engine should _not_ be warmed up, but started up and ridden away immediately.

 

Andy

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That's what ALL owners manuals, cars or bikes say. I've been told that's primarily due to emissions/pollution related concerns. I feel there is something that gets in the way of proper combustion and causes the engine speed to drop for a few seconds and then creep back up. I don't smell excessively rich combustion at start up, otherwise I would have suspected a drippy injector or two.

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That's what ALL owners manuals, cars or bikes say.

 

Morning Kalali

 

But BMW really means it on the 1100/1150 bikes as the exhaust system runs close to plastic & there is no cooling fan to come on & cool it.

 

Most newer cars & light trucks have computer controlled idle control so automatically drop the fast idle if the owner forgets-- the BMW 1100/1150 doesn't have that option.

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That's what ALL owners manuals, cars or bikes say.

 

Most newer cars & light trucks have computer controlled idle control so automatically drop the fast idle if the owner forgets-- the BMW 1100/1150 doesn't have that option.

 

Exactly. That's what I do with my cars - I drive away as soon as the engine speed drops to normal idle, usually around a minute and half or so.

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