Engine hesitating under load

[glennis]

Hi,

I'm currently travelling in Nepal on my 2006 R1200GSA which has developed an engine problem under hard acceleration. Regardless of engine RPM if I twist the throttle quickly the engine misfires/hesitates.

I have replaced all four spark plugs, cleaned the airfilter (K&N) and recently replaced the oil to no avail.

I have also disconnected both the secondary HT coils one at a time and started the bike with only the left or right disconnected. With the left secondary coil disconnected the bike starts with no problem, but when the right secondary coil is disconnected the bike does not start. I therefore believe that there is a problem with the secondary ignition circuit on the left cylinder.

As I'm in Nepal its very difficult and time consuming to arrange parts so I want to ask what other checks I can perform to narrow down exactly what part has failed before ordering. Maybe faulty wiring, HT coil or maybe something else like fuelling??? How can I determine what is the problem?

Looking forward to your responses.

Cheers
Glenn

 

[dippy]

if you have the bike running and disconnect one of the primary coils, unplug it, dont pull it out, the engine noise should change but only a very small amount, if so then that coil is ok. if the engine noise goes to rat shit then that would point at the secondary coil.

hope this helps

 

[DrogoNevets]

had a similar problem recently, turnout to be a loose cable

the throttle body was also stuck open for some reason. The cable the dealer (Vines) rekoned jsut became loose from normal vibration

ive attached an image to the cable that was loose on mine, hope you get it fixed what ever it is

 

[Fanum]

Hi,


I have also disconnected both the secondary HT coils one at a time and started the bike with only the left or right disconnected. With the left secondary coil disconnected the bike starts with no problem, but when the right secondary coil is disconnected the bike does not start. I therefore believe that there is a problem with the secondary ignition circuit on the left cylinder.

Now swap the 'working' coil over to the other side to make sure the problem changes sides.

If it does, it's almost certainly the coil pack breaking down.

If you can find a scrapyard with any modern(ish) cars that use coil packs, you may be able to find an ignition lead with a coil pack that you can use temporarily......I found one off a BMW325i or similar that got me through a trip once....I had to trim the rubber boot off with a knife to get it to fit down the spark plug hole, and I had about 3 feet of extra HT cable to route safely on the big, but it worked

(The ones you have on your bike come off the end of the lead with a clipped plug/socket, but most cars seem to have them as a one piece affair.......the only thing you're looking for is the depth of coil pack, EG it has to reach and connect on to the spark plug, and the diameter of the replacement coil obviously has to fit into the barrel as well....it doesn't matter if it's an inch or two too long, you can just ride with the cover off, and it doesn't matter if you have too much cable, you can re-route or tie that away. you can crimp down the end of the coil pack that plugs onto the spark plug tip if you need to, as there are various different sizes of those)

The BMW OEM part number you want is 12137715853 , but that will have to come from a BMW Motorrad dealer unless you can have one sent in DHL to somewhere to pick it up......

Good luck

 

[davegs]

Misfire

What altitude are you at? I rode my 1150 at 17.200 ft in the andies and it was fine but down on power but how high are you? as nepal is a bit high is it not? could be a cobination but try the secondry coil business as this appears to be the usual problem.
dave gs (very envious of your trip!)

 

[glennis]

Thanks for the help guys. I'll give all the suggestions a go tomorrow.

Fanum - Is it okay to swap the secondary coils over. I think I read somewhere that the left and right are different - maybe just the housing.

davegs - Unfortunately altitude is not the cause. This started happening on the plains in India. Currently in Kathmandu (1600m) and problems still exists. Highest pass I've been over was Tajikistan on the Pamir highway (4600m) and was running okay but had noticeable reduction in power.

Cheers

 

[Fanum]

Thanks for the help guys. I'll give all the suggestions a go tomorrow.

Fanum - Is it okay to swap the secondary coils over. I think I read somewhere that the left and right are different - maybe just the housing.

Cheers

Absolutely fine.....the parts are identical for the upper plugs.......the lower ones are angled differently though as you can see two part numbers on the picture below. (I would imagine on the lower ones it's purely a shape/convenience thing though and they are interchangeable in reality)

LINKY TO PICTURE

The coil packs are also the same as on the 1150 twin spark, so if you are with anyone with one of those (superior) models, you can swap them about and you should be able to demonstrate which pack is breaking down.

They break down internally and there's not much you can do with them, but you can't hurt it by taking the coil pack indoors, thoroughly drying it and cleaning it off.....clean all the terminals as well, and you MAY get a bit more current flowing through it (it's unlikely though)

In your situation, I'd try a little grease on the casing of the coil pack as well, in the hope that it might stop the magic electricity leaking, and it'll help stop it getting wetter *BE CAREFUL* undoing the little three pin multiplug from the end of the coil pack/junction to the lead...they aren't the strongest things in the world and I've seen them broken before now.

Afterthought.......clean and if possible, change or clean the primary and secondary spark plug on the dead side as well.......if it hasn't been firing well, it will have got a bit shitty and anything you can do to give you a better stronger spark will be good, even if it is the coil pack that's failing


There have been (at least) 3 generations of the coil packs.......the first ones were all black and failed quite often (early 1150s) then they replaced them with a similar pack that had a grey top to it (the top that shows on the end of the pack when it's in place)
The latest, and supposedly best version have the whole top in grey plastic......if you get a choice when buying a new one, make sure you get the latest version, although any will do the job and they're all interchangeable

 

[alex_rsa]

Did you have the main coils disconnected as well?

The bike will start and run (very lumpy) on 1 working coil pack. You can swap it left to right to confirm that it is a duff coil pack and not the wiring to it.

Once you have confirmed it you will need another one.

I never tried riding with both secondary coils disconected, but it should be possible and may stop hesistating, that may allow you to continue before your part arrives.

As has been said before any coil pack should work and the bottom ones have far more space around them than the tops ones so you may be able to bodge another coil in there as a temporary fix.

 

[glennis]

Both primary coils were connected whilst unplugging the secondary coils one at a time.

With the right secondary disconnected and the suspected faulty left secondary connected the bike would not start. It would just cough and splutter.

Alex_rsa - You mentioned the bike will run on one coil pack. Do mean with 3 coil packs disconnected that the bike should start? Mine will not start with both primaries on and secondaries off. Do you think there maybe another problem?

Fanum - I've changed all spark plugs less than 500km ago. Will swap over secondary coil packs and let you know how I get on tomorrow.

Thanks again for everyone's help.

 

[alex_rsa]

Yes, one working coil pack will get it started.

Have a search as I wrote out the procedure before. But basically disconnect all the coils (you can just unclip them at the wiring harness). And try one at a time.

It should start and run on 1 coil pack. If it does not, it is potentially dead. Try the same coil pack on the alternate side. If it does not start again it is the coil pack.

 

[StumpyFingers]

How clean is the air filter? The symptoms you describe could be due to a blocked filter.


Sent from my iPad using Tapatalk HD

 

[glennis]

Okay, so I've done some very methodical testing and here are the results:

LP = Left Primary Coil Pack
RP = Right Primary Coil Pack
LS = Left Secondary Coil Pack
RS = Right Secondary Coil Pack
Start = Engine Started

Apologies for the crappy formatting

LP RP LS RS Start Notes
0 0 0 0 No Obviously did not start
0 0 0 1 No Single Coil Pack - Did not start
0 0 1 0 No Single Coil Pack - Did not start
0 0 1 1 Yes Both Secondary Coil Packs - Engine Started
0 1 0 0 No Single Coil Pack - Did not start
0 1 0 1 No Both left coils not connected
0 1 1 0 Yes One left, one right connected - Engine Start
0 1 1 1 Yes Left primary disconnected - Engine Start
1 0 0 0 No Single Coil Pack - Did not start
1 0 0 1 No One left, one right connected - NO START
1 0 1 0 No Both right coils disconnected
1 0 1 1 Yes Started on LS & RS only
1 1 0 0 No Should have started
1 1 0 1 No Should have started
1 1 1 0 Yes
1 1 1 1 Yes

In summary

1. Did not start if only one coil pack was connected
2. Started with only secondaries connected
3. Did not start with only primaries connected
4. Did not start if one cylinder had both coil packs disconnected

Summary point 3 indicates that one of the primary coil packs or wiring to it has failed. Repeating the test for the underlined rows above but with the the primary coils swapped over indicated there is a failure of the left primary coil.

Alex_rsa - Engine did not start with only one coil pack connected. Could this indicate that all coils pack are generating a weak spark and need to be replaced?

StumpyFingers - I have a K&N filter that I recently cleaned and oiled. This is the first time I've re-oiled an air filter but was cautious of putting too much oil on the filter as this my clog it. I might remove the air filter completely and try starting the bike on a single coil pack as Alex_rsa has indicated bike should run like this.

Thanks for everyone's advice