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Hard to Start


roundy

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roger 04 rt

If you can shim the throttle open by 0.050 to 0.100" you would by adding a controlled amount of air. I think 0.085" would be about 5 degrees added throttle. If it cold started well then you'd know it was merely a bit of extra air needed.

 

The other thing you could try is shimming one side by 0.020" which would offset it one degree. See if the BMSK figures it out and fixes it by adjusting the idle stepper on that side.

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The other thing you could try is shimming one side by 0.020" which would offset it one degree. See if the BMSK figures it out and fixes it by adjusting the idle stepper on that side.

 

Afternoon Roger

 

Good idea, unfortunately the 1200 is a b!tch to get to the throttle cams as there is a cover over that area on the TB's.

 

Might be easier & quicker to just uncap one of the TB nipples & let the extra air in that way. (he can do this without even removing the Tupperware with a pair of hemostats or very longnose pliers by reaching in to the nipple area)

 

I'm still trying to figure out (understand) his stepper issue as they NEVER seem to vary cross-side-to-side (even way back on his pre starting problem data trapped back in 4 of 2014.

 

His warm engine curb idle stepper counts are higher than they should be & seem to be totally linked side to side. I'm just not sure why. Might be as simple as a restricted air flow past the throttle plates, or partially plugged stepper air by-pass passages, or coked up stepper pintles so the BMS-K is commanding higher counts to achieve proper idle RPM.

 

Possibly????, at a certain stepper count the computer forces cross side linking (like it does as the throttle is opened).

 

I just don't have enough background in the 1200 BMS-K stepper control area to fully understand what the high idle count & linked stepper position is telling us. (I'm hoping he finds a smoking gun on this so we can understand it better)

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roger 04 rt

The other thing you could try is shimming one side by 0.020" which would offset it one degree. See if the BMSK figures it out and fixes it by adjusting the idle stepper on that side.

 

Afternoon Roger

 

Good idea, unfortunately the 1200 is a b!tch to get to the throttle cams as there is a cover over that area on the TB's.

 

Might be easier & quicker to just uncap one of the TB nipples & let the extra air in that way. (he can do this without even removing the Tupperware with a pair of hemostats or very longnose pliers by reaching in to the nipple area)

 

I'm still trying to figure out (understand) his stepper issue as they NEVER seem to vary cross-side-to-side (even way back on his pre starting problem data trapped back in 4 of 2014.

 

His warm engine curb idle stepper counts are higher than they should be & seem to be totally linked side to side. I'm just not sure why. Might be as simple as a restricted air flow past the throttle plates, or partially plugged stepper air by-pass passages, or coked up stepper pintles so the BMS-K is commanding higher counts to achieve proper idle RPM.

 

Possibly????, at a certain stepper count the computer forces cross side linking (like it does as the throttle is opened).

 

I just don't have enough background in the 1200 BMS-K stepper control area to fully understand what the high idle count & linked stepper position is telling us. (I'm hoping he finds a smoking gun on this so we can understand it better)

 

 

DR, Assuming that he hasn't disconnected the Evap canister, in a 5-10 minute hot log, there should be one or two examples of the purge valve opening and the steppers diverging. I wonder what's going on there? Does his bike only draw evap air from the left side like the other R1200GS I worked on?

 

Like I mentioned I won't have all my files for a week so can't get a good comparison.

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Evening Roundy

 

Just a quick thought here--

 

You might take a look at your TB's next time you open the plastic up to see if the base idle screws have ever been messed with.

 

If they are intact you should see the blue indexing paint marking the screw position & the paint line shouldn't be broken.

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Fascinating tread.

Just out of curiosity, is it possible he has a vacuum or air leak between the throttle body(s) and the intake valves?

Cracked intake tube? Leaking head gasket?

I don't really know, just trowing out some ideas.

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Evening Bernie

 

Sure that is possible but you would think that would give him lower commanded stepper counts as the computer tries to lower the idle RPM's.

 

We will see what the data shows when he intentionally introduces an air leak by uncapping a TB nipple.

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Morning all! Nasty windy wet morning here in Blighty, but been out in the garage having fun replacing a fork seal on the Sportster!

 

Firstly checked my battery, good healthy voltage at standstill (above 12v) Put the tester on and held strong at 11v for over 10 secs - so pretty sure my battery is good.

 

So here is a log, cold start - and interesting as she started fine with no throttle. Removed the left side nipple about 30 secs in - stepper counts were identical on both at all times, let it run with one off for a good minute or two.

 

https://dl.dropboxusercontent.com/u/46259303/cold%20start%20removing%20nipple%20after%2030%20secs.csv

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Morning Roundy

 

I'm not sure you got it hot enough to show much as the stepper count remained pretty high through the entire run. (that thing might have still been pulling hard against cold thick engine oil & thick trans gear oil)

 

Sure didn't show much response to the nipple uncap did it.

 

I don't know what to tell you except to tell you to try cleaning the throttle bores & the stepper air passages as well as cleaning the stepper pintle tips & seats. (at least then we will know this is or isn't the issue)

 

Are you SURE the TB idle stop screws haven't been messed with???

 

 

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TB screws certainly haven't been touched by me in the 6 nearly 7 years I've owned her.

 

Will get her warmer and run the test again, then try some cleaning!

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So had a bit of a look at the TBs tonight, to be honest not that bad I thought, right side was worse than left. Idle air holes aren't blocked either from what I can tell, gave them a good squire anyway. Also no play on the butterfly shafts.

 

This is the left side https://www.dropbox.com/s/ec51ru0ok2llcxo/DSC_0350.JPG?dl=0

 

Gave the connections on the back of the starter a real good going over too, they were pretty rusty and corroded. Will run her up tomorrow and see how things are.

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Afternoon Roundy

 

 

That looks pretty clean. Too bad as we are now back to square 1 on what your problem is.

 

Any signs the base idle throttle stop screws were ever messed with?

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Evening DR,

 

Didn't check, do they have paint on them?

 

So, when she is warm, removing a nipple should trigger the stepper to adjust the airflow down yes? If my steppers stay the same (commanded) value what does that mean?

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Continued where I left off with cleaning connections this evening as the fairing was off so I decided to take a look at the earth on the engine. Attempted to undo the small torx bolt and it sheared right off!! :-(

 

Moved the position of it, but judging by the state of the contact surface and the corroded bolt I am thinking it's probably a real naff earth point!

 

https://dl.dropboxusercontent.com/u/46259303/DSC_0351.JPG

 

Have cleared the adaptations and will see how she starts in the AM.

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Ok, so perhaps this AM wasn't the best time to test, considering I had the fuel lines disconnected yesterday and the TBs were full of carb clean.

 

Cold start at work tonight and she still struggled to start, but at least she did start without throttle, probably through more fluke than anything.

 

When I arrived home this evening I didn't switch off and completed some logs. One minute of idle, then I removed the left side TB nipple, from what I can see no change in the commanded stepper value?? Bike was idling lumpy and you could hear the revs hunting about, still at square one :-(

 

https://dl.dropboxusercontent.com/u/46259303/30-03-15%20hot%20after%20ride.csv

 

Random question, but could timing cause this kind of issue??!

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Afternoon Roundy

 

Ok, that one opened. --nothing major stands out.

 

Sure timing could effect it but on the 1200 the timing is set in stone by the pickup reading the crank gear so I have no idea what could change it.

 

That is the strangest thing that removing a TB nipple cap doesn't seem to change it enough to show on stepper count command.

 

I think we are at the point of looking at non monitored things, like (all 4) stick coil operation, engine compression, fuel pressure, valve opening distance, etc

 

With the engine idling rough hot but not much showing on the GS-911 data I think I would start with stick coil operation. If it runs OK going down the road, then, (IF) a stick coil problem it's probably lowers.

 

 

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The lowers are like less than 6 months old :-( Technically still under warranty but how the hell can BMW test them!!

 

I did notice the other day when I pulled one of the uppers some small blisters that had gone rusty on one.

 

Man this sucks....replacing all the coils is like throwing money away! I suppose it makes sense with the poor starting if I have a duff coil.

 

Should the bike run on just the lowers? Thinking I can disconnect both uppers and then see if she still runs - no way it could run on one lower if i have a duff one.

 

Is there an easy way of checking fuel pressure?

 

Also, just to add in case its a indicator, I swear it sounds like its pinging real bad..?

 

Last thing :-D - if i get an infra red thermometer do you think that might help me pin point which cylinder is causing me the grief? Surely a side with a coil down or something like that may run cooler?

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Also, just to add in case its a indicator, I swear it sounds like its pinging real bad..?

 

Afternoon Roundy

 

That pinging sound can (not definite though) indicate a coil not working.

 

See if it will run on just the uppers, then see if it will run on just the lowers (might take a bit of throttle to keep it running on just the lowers.

 

Fuel pressure check is difficult without a pressure gauge & a way to hook it to your fuel system. If the bike will run out to 175-180kph then it probably has enough fuel pressure.

 

A temp gun might show you something but also might not if it is firing on at least one plug per cylinder. Are the front pipes the same color?

 

Have you put a U tube manometer on it after a hot run home? With those steppers locked to the same counts (seems to be a European thing without evap system) maybe a balance check will show us something.

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Ok DR - I'll start on the case, will try the carb tune on here after a hot run, with a set of pliers I think I can get the tubes on.

 

She'll defo do 175kph (108mph) easy... Front pipes are the same colour, brown :-D

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Roundy, I think you are only running on the lower stick coils.

I regularly test mine, by starting the bike cold with only the bottom ones connected and then check if temperature in both exhaust pipes rises the same, you can also get a reading on your GS-911.

The idle will be lumpy and irregular, but it will run. Heck you could even go so far and just try to start it on one coil at a time and see if it ignites and it may idle somewhat. These test will let you know if the bottom cols work at all.

Then do the same with the center coils, disconnect the bottom coils and start the motor, if it barley runs on one cylinder, the other side must be bad. It only takes one bad stick coil to ruin your day.

 

Also the rusty center stick coil is very suspect, since every bad coil I have seen has been rusty or discolored.

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Don't forget how easy it is to damage wire/coil connections on these bikes if you mishandle coil removal. Easy and controlled is the key.

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So the other day after the ride home I disconnected the upper coils, bike still ran, a bit worse but still not all the that great.

 

This evening I disconnected the lowers and started the bike up and she ran, again a bit worse but not all that much worse.

 

On both occasions the bike seems just as bad in terms of hunting about and mis-fire type idle.

 

Have stripped the fairing off the bike tonight so going to take her for a run to warm up and then check the idle balance on the CarbTune.

 

Any other suggestions for tests tomorrow would be welcome!

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Afternoon all!

 

Spent some time riding the RT this AM with different scenarios, after I've established that the bike will run on either upper or lowers.

 

Rode the bike and got her up to temperature then;

 

Running on just uppers, seems to run ok up above 3k rpm, but very rough below 3k rpm, surging, mis-fire generally crap riding slow at around 20/30mph.

 

Running on just lowers, basically as above but pretty much at all times. (Which I assume is to be expected as they are never intended to be the primary coils.

 

When I got home I put the Carbtune on her and below are the results, the idle balance is off, defo....

 

Pictures of idle balance:

https://dl.dropboxusercontent.com/u/46259303/DSC_0401.JPG

https://dl.dropboxusercontent.com/u/46259303/DSC_0399.JPG

https://dl.dropboxusercontent.com/u/46259303/DSC_0398.JPG

https://dl.dropboxusercontent.com/u/46259303/DSC_0400.JPG

(Left tube is left cylinder, right is right as sat on the bike)

 

Video (running at idle then up to 3k, you can see it balance out)

https://dl.dropboxusercontent.com/u/46259303/MOV_0402.mp4

 

I am wondering if first point of call is upper coils? Surely they shouldn't have been behaving like they were when on their own?

 

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Morning Roundy

 

The BMW spec is up to 25 mbar side to side variance @ idle (that is about 1.8 cmhg so you are at or pretty darn close to the max allowable cross side vacuum difference at hot curb idle).

 

It does seem to straighten out as your revv it above idle so the cables seem adjusted OK .

 

Your engine does sound kind or trashy at idle though. Sure is a possible you have a bad upper coil but you would think a bad coil would be bad all the way through the RPM range. (be nice if you could borrow a couple of "known good" upper coils)

 

 

On the upper/lower plug disconnect-- what you are seeing is pretty normal as the uppers control basic combustion timing all the way through the range but the lowers only spark in time at lower RPM's & are phase shifted out of time at higher RPM's so they basically contribute nothing from mid range up.

 

All this & we STILL don't know what your problem is.

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So frustrating, might just bite the bullet and get some upper coils, may get lucky :-S

 

From looking at the gauge can u tell which side is acting up? Assume you'd need to see the same gauge on a good bike.

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So frustrating, might just bite the bullet and get some upper coils, may get lucky :-S

 

From looking at the gauge can u tell which side is acting up? Assume you'd need to see the same gauge on a good bike.

 

Afternoon Roundy

 

Not really as the vacuum you are measuring is not related to spark it's only related to inlet Delta-P.

 

If you could find a way to back drive the engine you could conceivably set the TB balance with the key turned off.

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Did Roger notice from the logs that one side was having to get more fuel injected, could that be to balance out the issue?

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roundy,

 

I see you posted a video earlier in the thread. Can you post another while trying to start it?

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Morning Roundy

 

That thing sure doesn't sound strong on the closed throttle starting.

 

Now that you have a baseline video of the poor start--

 

If you can get the time try another couple of cold starts (no throttle) on.

 

Just the upper spark plugs.

 

Just the lower spark plugs.

 

If one or the other (upper/lower) plug starts matches your video then maybe you can determine IF one set of coils isn't contributing to the cold starting.

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DR suggested a while back to jump that battery. Was that every tried? I read where the voltage was checked, but I don't think it was load tested? Or better yet swap that thing out for a known good battery. (maybe from the pretty yellow one next to it.)

 

I still don't like the fact that you're problems started shortly after a new battery was installed.

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Air temp was above 10 degrees celcius, lovely day.

 

Battery was load tested, held a strong 11v for well over 10 seconds.

 

Surely if I have one cylinder pulling less it will struggle to start. Gonna let her cool down and try the plug thing. She is warm now as I switched left and right mains to see if ththe imbalance switched, no luck.

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I just load tested the old battery that came off and it held at 10v for 10sec, gonna put it on charge over night and then use that to jump....or should I use the car?

 

I am still in the camp that my cylinder imbalance is behind the starting issues.

 

The moment the bike is warm she'll start fine.

 

Would low compression cause the imbalance?

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If the old battery was ok when you replaced it, then I would just swap it. But then, why did you replace it? Maybe jump it with the old one?

 

I just think you need to rule out the battery as the problem, because it's easy. And I'm not sure that's been done.

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Morning Roundy

 

I just load tested the old battery that came off and it held at 10v for 10sec, gonna put it on charge over night and then use that to jump....or should I use the car?---Car would be best as it has the highest amperage battery. Do not start the car just jump from passive battery.

 

I am still in the camp that my cylinder imbalance is behind the starting issues.---Your cold cranking balance isn't off THAT far. I would be very surprised if base stating cross side balance was your issue.

 

The moment the bike is warm she'll start fine.--- this more points to something other than cross side balance.

 

Would low compression cause the imbalance?--- Yes, very possibly but only IF the low compression was different side to side. But low compression could account for your poor cold starting.

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To answer the "how did I load test" question, I have a battery drop tester.

 

She wouldn't start this AM, so I proceeded with the following;

 

Lowers only - https://dl.dropboxusercontent.com/u/46259303/Lowers.mp4

 

Uppers only - https://dl.dropboxusercontent.com/u/46259303/Uppers.mp4

 

With another m/c battery connected in line - https://dl.dropboxusercontent.com/u/46259303/BatteryJump.mp4

 

I popped the CarbTune on yesterday from a cold start as well: https://dl.dropboxusercontent.com/u/46259303/DSC_0408.JPG

https://dl.dropboxusercontent.com/u/46259303/DSC_0409.JPG

 

I also looked at the battery figures when starting again, 12.8 idle, 9.5v initial crank drop levelling out to 11.5 (pretty sure I've ruled out the battery now)

 

I have a compression testing kit on the way, but I am off to Ireland for a few days now so will have to pick this up when I am back.

 

Thanks a million everyone so far for your input on this, such a massive help!

 

(If I get time when I come home I'll try jumping from the car battery.)

 

 

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Hey everyone, back from Ireland and have completed a compression test in the RT.

 

Back from an hour ride and bike has been off for 2hrs so let her idle to get temp gauge half way. Throttle wide open, cranked from 5 seconds.

 

Left cylinder 180psi

Right cylinder 195psi

 

So don't think that's the issue? Not sure what Bmw's spec is, but my gut says for a 78k mile bike that difference is fine?

 

The more I think about this, the idle balance would cause issues starting no? So, when I open the throttle the cylinders balance out hence why she starts.

 

Anyone thinking I have an idle air leak, like a worn stepper pintle maybe??

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Hey everyone, back from Ireland and have completed a compression test in the RT.

 

Back from an hour ride and bike has been off for 2hrs so let her idle to get temp gauge half way. Throttle wide open, cranked from 5 seconds.

 

Left cylinder 180psi

Right cylinder 195psi

 

So don't think that's the issue? Not sure what Bmw's spec is, but my gut says for a 78k mile bike that difference is fine?

 

The more I think about this, the idle balance would cause issues starting no? So, when I open the throttle the cylinders balance out hence why she starts.

 

Anyone thinking I have an idle air leak, like a worn stepper pintle maybe??

IIRC, the general rule of thumb is no more than 10% difference between cylinders warmed up. I don't know what the number is that BMW calls out, but almost 200 psi is more than I've seen on many vehicles I've worked on. At least for the delta, it looks like you're within spec.

 

You should notice a steady increase in pressure with each rotation.

 

JayJay

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Afternoon Roundy

 

Did you test compression with throttle held wide open? (you need to)

 

Did you allow the injectors to keep squirting fuel in during cranking (that skews the readings)

 

Engine cranking speed can also alter the readings.

 

But no matter as you compression readings look pretty decent.

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Throttle wide open

Injectors still connected

Cranking speed was consistent and good IMHO

 

Going to get some stepper motor o-rings first to make sure no air is leaking past. Then perhaps one nee stepper...

 

Good plan?

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  • 3 weeks later...

Sunday I replaced the o-rings.

 

Tried to start before I did the work and she started, but cracked on anyway.

 

Replaced both o-rings and re-did the valve clearances just to be on the safe side. Started up fine, then tried again in the afternoon and again in the morning on Monday, all fine.

 

Went to go to work this AM, wouldn't start without throttle?!?!? Arrrrgggg!!

 

After I had done all the work I reset the adaptations and did a TPS re-learn (although I didn't pull the battery, maybe I should do that? Not sure if reset adaptations wipes it or not).

 

But interesting as this morning the bloody thing kept cutting out when I was blipping the throttle when rolling to a stop on idle.

 

Point to note this morning was that when it did start the idle was very low, almost like it was not in cold start and it should be...?

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dirtrider

Morning Roundy

 

This problem is getting more & more complex.

 

Have you tried running it with an FPC (Fuel Pump Controller) by-pass cable to run the fuel pump at full power? (maybe it's in the above pages somewhere but I can't remember if you did)

 

If you can get it to act up (cutting out) with a GS-911 on it maybe we can spot something in the data stream.

 

 

 

 

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Guest Kakugo

Roundy, I have a brand new, still in its original plastic bag spare FPC I carry on my bike as a spare on long trips.

 

Given I am probably the nearest member to you (and hence the one who would paid lowest postage rates), I can send it over to you to try out and rule that part out.

If it's the FPC, you can send back mine and buy a new one or keep mine and send me another new one you'll get from BMW.

If it's not the FPC, just Paypal me the money for the postage and send it back to me.

 

Given it's light and small, I can probably send it over to you by express mail without killing you with shipping rates.

PM me if interested.

 

Be mindful I am leaving for France in two weeks hence it's either right now or after I am back.

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