Idle problem exacerbated by PCV - any ideas?

[motorbaker]

Hi. 2007 GSA. Idle is unsteady, especially when engine is warm - feels like it might stall but doesn't quite - no problems at speed. When I plug in a Power Commander V (with custom map) the problem is worse and the engine does actually stall from time to time when I come to idle, and I have to recycle the ignition to get it to restart.

But the problem exists without the PC too, and was verified by Steptoe last week during a service (with the PC disconnected). I'm taking the bike back to him tomorrow to try to get the issue resolved, and have trawled through the forum for possible causes.

How likely is it to be one of these?

Coils
Vacuum leak
Faulty stepper motor
Crank sensor
Interference to throttle cable from other wires (Autocom, Zumo 660 both installed)

If any of these would make the problem worse if the PC was connected, then I suppose this would be the place to start looking tomorrow.

Any advice much appreciated.

Cheers,

MB

 

[trainman]

Hi. 2007 GSA. Idle is unsteady, especially when engine is warm - feels like it might stall but doesn't quite - no problems at speed. When I plug in a Power Commander V (with custom map) the problem is worse and the engine does actually stall from time to time when I come to idle, and I have to recycle the ignition to get it to restart.

But the problem exists without the PC too, and was verified by Steptoe last week during a service (with the PC disconnected). I'm taking the bike back to him tomorrow to try to get the issue resolved, and have trawled through the forum for possible causes.

How likely is it to be one of these?

Coils
Vacuum leak
Faulty stepper motor
Crank sensor
Interference to throttle cable from other wires (Autocom, Zumo 660 both installed)

If any of these would make the problem worse if the PC was connected, then I suppose this would be the place to start looking tomorrow.

Any advice much appreciated.

Cheers,

MB

if its really worse when warm it could be the engine temp sensor playing up

as you say coils too which many have found affected by heat - see other posts which indicate visible signs of distress normally (easy to borrow a set from Steptoe maybe?)

crank sensor - if faulty would expect the same fault whatever the temp??

 

[motorbaker]

Thanks. Worse when warm could be my imagination! I guess looking at the coils is a good place to start, as you say.

I noticed that the plug for the right stepper motor has a bit of corrosion. Could that be a possible factor?

 

[Schtum]

Have you removed the lambda sensors or have you fitted the Autotune kit, ie the two wideband lambda sensors for the PCV?

As I understand it, you should have removed the OEM sensors when fitting the Power Commander.

I experienced similar symptoms which were traced to failed lambda sensors.

 

[motorbaker]

Yes I've unplugged the lambda sensors when the PC is on and replug them when it's not. As the idle issue remains either way isn't it logical to presume that the lambda sensors are not therefore the cause? Happy to be corrected.

On a side issue, what do you do with them when unplugged? I don't like the idea that the plugs just hang loose and exposed at the bottom of the bike.

 

[motorbaker]

Well, it wasn't the coils - they're fine. I'm going to have BMW check it out and see what they come up with.

 

[motorbaker]

Perhaps some video evidence will help:

http://www.youtube.com/watch?v=YZ8ply61mRI

Started bike from cold with PCV inline - ran beautifully - rode around town for 10 minutes and this happened once engine was up to operating temperature.

 

[DrFarkoff]

Do you have an accelerator recyclizer module attached too?

What plugs are you using?

Iridium????

Sounds like the steppers can act fast enough to compensate for over fuelling that's why the lamdas are there for when the engine is hot to monitor exhaust gasses and readjust fuelling to suit

 

[motorbaker]

Do you have an accelerator recyclizer module attached too?

What plugs are you using?

Iridium????

Sounds like the steppers can act fast enough to compensate for over fuelling that's why the lamdas are there for when the engine is hot to monitor exhaust gasses and readjust fuelling to suit

No, just the PC with a custom map.

Re plugs, whatever Steptoe put on at the 36k service last week.

Without the PC 5 it won't stall, but the idle is still rough, just a bit higher (1 to 1.2k) than with the PC.

 

[DrFarkoff]

Without the PC 5 it won't stall, but the idle is still rough, just a bit higher (1 to 1.2k) than with the PC.

Still think it's too rich if you crack the throttle open by a mil or 2 does it even out?

 

[motorbaker]

Still think it's too rich if you crack the throttle open by a mil or 2 does it even out?

It evens out but higher up in the rev area, around 2k and up I would say. Sometimes, when it's about to stall, if I just twist the throttle a bit it will oscillate between near stall and 3k revs but won't stabilise in between.

I originally thought it was a PC problem but Dynojet have sent me a replacement and it's made no difference. But the problem is worse with the PC.

 

[DrFarkoff]

Anyone around got an exhaust gas analyzer?

Start the machine go for a run around the block and come in and see what the CO reading is If it's above 3 it's Waaaaaaaaaaaaaaaaaaaay too rich if it's 0.5 to 1.2 it's what R1200 are around ish We used to set the older bike (before lamda) to around 1.5 to 2.25 % CO

At least it's a starting point rather than trying to second guess

Also have you removed the stepper motors and cleaned their orifii and tip soot and oil gunge won;t let them work correctly??

 

[trainman]

No, just the PC with a custom map.

Re plugs, whatever Steptoe put on at the 36k service last week.

Without the PC 5 it won't stall, but the idle is still rough, just a bit higher (1 to 1.2k) than with the PC.

seems like we have had a few posts like this with issues post service, could it not be any of the parts you have changed or disturbed (tank off?, valves?, plug connections etc etc)

my moneys on something being disturbed or a faulty part fitted

 

[motorbaker]

Anyone around got an exhaust gas analyzer?

Start the machine go for a run around the block and come in and see what the CO reading is If it's above 3 it's Waaaaaaaaaaaaaaaaaaaay too rich if it's 0.5 to 1.2 it's what R1200 are around ish We used to set the older bike (before lamda) to around 1.5 to 2.25 % CO

At least it's a starting point rather than trying to second guess

Also have you removed the stepper motors and cleaned their orifii and tip soot and oil gunge won;t let them work correctly??

Unfortunately I don't have access to that sort of equipment, but I have booked it in to BMW next week so I could ask them to do it I guess.

Is removing and cleaning the stepper motors something a mechanical novice like I could do?

Here's one more video link showing how the engine behaves

http://www.youtube.com/watch?v=nLhPW2qHmnw

 

[motorbaker]

seems like we have had a few posts like this with issues post service, could it not be any of the parts you have changed or disturbed (tank off?, valves?, plug connections etc etc)

my moneys on something being disturbed or a faulty part fitted

I think not as the problem was there before the latest service. The rough idle has been there for quite a while - I didn't realise it wasn't normal - but only became a problem around Easter when I first fitted the PC. So if something wasn't done right I have no idea when!

 

[Pukmeister]

Are your plugs heavily fouled?? If so, your lambda probes will be too, resulting in the bike running like shit, a catch 22 situation.

 

[motorbaker]

Are your plugs heavily fouled?? If so, your lambda probes will be too, resulting in the bike running like shit, a catch 22 situation.

Presume not - it's just had a 36k service.

 

[motorbaker]

Had it checked by a BMW dealer today. Here's the result:

https://docs.google.com/viewer?a=v&...MDYzNy00ZTJlLTllNjYtYWI5MDBhNjE1ZTJk&hl=en_GB

Nobody actually said "They all do that sir" but the man on the desk did ask me "How familiar are you with boxer engines, sir, if you know what I mean?"

Managed to get a chat with the engineer which was great, and it seems the only option is to leave it there for a longer period of time. But at £117.60 per hour (of which I've already forked over one whole chunk) I think I'll just have to live with it and leave the Power Commander off so at least it won't keep stalling.

 

[davidblythe]

These are my observations only,

have a 1200 gsa with pc5 and autotune, i do a lot of running around town, when i started with just the pc5, the bike wasnt to clever around town, felt very rich and would stall, on runs it was fine

bought the autotune and set my own af parameters and then established a % base map from various long runs

now when town running, the trim goes very negative -20 at low throttle openings for most revs, if i accept these trims into the base map then go on a long run, the bike feels very lean for about 10 miles as the trims then go very positive

in my experience a cast in stone map is not sufficient for all types of running

am very happy with the autotune addition

please fell welcome to ignore the above,

 

[motorbaker]

Hi David, that's really helpful - thanks!

About the autotune: does it have O2 sensors which replace the BMW ones or does it plug into the existing ones? And what have you done with the loose BMW plugs? And is there a readout on the bike or do you simply connect it to a laptop in between rides to make adjustments?

Sorry for all the questions.

All best,

M