Surging cured, but how?

Muppet · Sep 20, 2004

Got a 99 (T reg) 1100 which used to suffer from the dreaded surging. I put a K&N filter in, and this only seemed to make it more acute! I know I should get the throttle bodies balanced, but haven't got round to it yet. Anyway, by chance I happened to meet up with the bikes previous owner and talked to him about it. He said it was easily cured by removing a solenoid from the fuse box area. The one signified by my dainty little digit here.

So, I took it out, and bugger me sideways it works! No surging, at all. I can now trickle around in top gear at under 2,000 rpm, on a whiff of a throttle and it just purrs smoothly along. Same in any gear, at any revs, it will now hold those revs beautifully with no hunting or surging at all. Oh joy!

Question is, what have I done? Have I done something with the closed loop injection system, if so what, and will it have a negative effect? If not, why don't BMW do this? Doesn anyone have the answers?

Le singe · Sep 20, 2004

I've got a '94 R1100GS, this used to have the beige coding plug fitted. I removed it,as you've done,which means the fuelling reverts to a 'safety' map,approximately,I believe,4-5% richer than with the plug fitted. I did a crude plug chop after removal and the plugs were significantly darker,therefore confirming it was running richer. I then modified the standard silencer and cut a hole in the rhs of the airbox.
The plug colour is now just slightly richer than with the coding plug fitted,torque wise,the roll-on between 3500 and 5500rpm is considerably better with no evidence of surging anywhere.
Your surging has disappeared because the system is running richer,most chips sold to eradicate this problem just richen things in the lower rpm region,you won't be running rich enough to wash the bores,but may notice a slight drop in mpg.

Le singe · Sep 20, 2004

Forgot to mention,fitting the K&N made the surging worse because it flows more than the paper filter,hence making the engine run slightly leaner adding to the problem.
Hope this helps.

NeilF · Oct 16, 2004

Just had my 1150 in at Premier Bikes in Didcot (nice guys) primarily to cure surging. They adjusted the valve clearances ('a little loose'), and balanced the throttles. Weren't sure about TPS adjustment so they didn't touch it.

They were concerned about the CO emission level which was 'just' 0.1% at tickover; should be about 3%? They changed the plugs which were also whitish, and replaced the air filter.

Surging was still there albeit somewhat reduced, and at 3200 - 3500 rpm instead of 2700 - 3000 rpm before the visit.

Seems like removing this coding plug may be the next action!

Cheers,

Neil

The Mechanic · Oct 17, 2004

Oh fer chris.. akes

NeilF said:
Just had my 1150 in at Premier Bikes in Didcot (nice guys) primarily to cure surging. They adjusted the valve clearances ('a little loose'), and balanced the throttles. Weren't sure about TPS adjustment so they didn't touch it.

They were concerned about the CO emission level which was 'just' 0.1% at tickover; should be about 3%? They changed the plugs which were also whitish, and replaced the air filter.

Surging was still there albeit somewhat reduced, and at 3200 - 3500 rpm instead of 2700 - 3000 rpm before the visit.

Seems like removing this coding plug may be the next action!

Cheers,

Neil

The Mechanic · Oct 17, 2004

Oh fer chris..akes

NeilF said:
Just had my 1150 in at Premier Bikes in Didcot (nice guys) primarily to cure surging. They adjusted the valve clearances ('a little loose'), and balanced the throttles. Weren't sure about TPS adjustment so they didn't touch it.

They were concerned about the CO emission level which was 'just' 0.1% at tickover; should be about 3%? They changed the plugs which were also whitish, and replaced the air filter.

Surging was still there albeit somewhat reduced, and at 3200 - 3500 rpm instead of 2700 - 3000 rpm before the visit.

Seems like removing this coding plug may be the next action!

Cheers,

Neil

Why in gods name do you people let these deliquents loose on your bikes..not sure about TPS adjustment. Bloody hell do they know what an ECU is?

Schtum · Oct 17, 2004

Clive, have you still got the double barrelled howitzer fitted on the side...?

ELIMINATOR · Oct 20, 2004

surging

There is an article in used bike guide about surging, throttle bodies need to be balanced regarding voltages. On the 1150 I believe it said remove fuse 5 for a minute,ignition off. Put the fuse back, ignition on [not engine running] open and close the throttle 3 times fully. This way the motronic system relearns the position of these and they should be balanced.

Bikergary · Dec 9, 2004

I'll have to try this, riding around oxford is such a pain when it keeps surging..

>>"Just had my 1150 in at Premier Bikes in Didcot (nice guys) primarily to cure surging. They adjusted the valve clearances ('a little loose'), and balanced the throttles. Weren't sure about TPS adjustment so they didn't touch it."
,--- I'm supprised they didn't, I know these guys quite well ( I live in Didcot and use them on occasions) as the two main guys are ex BMW mechanics......

>>"On the 1150 I believe it said remove fuse 5 for a minute,ignition off. Put the fuse back, ignition on [not engine running] open and close the throttle 3 times fully. This way the motronic system relearns the position of these and they should be balanced."
is this motronic system on the 1100? of so can I do this?

GSmonkey · Dec 9, 2004

I'm glad its just not the 1200's that surge!!

littleredrooster · Dec 10, 2004

Do a search on 'surging' and be prepared for a weekend's reading.......

Successful cures have included VERY careful balancing, TPS setting, cat code plug removal, Hall sensor replacement, different plugs, coil replacement, fitting of Techlusion box or being blessed by a witch-doctor.

The underlying theme, however, for the 1150 (& the 1200 if Bike magazine is to be believed) is that they run very lean in standard trim. Hence setting the TPS to a richer setting or adding a Techlusion box (as I have done), or removing the cat code plug (as in the post above) will improve matters. To fully complete the job, a dyno run is needed to measure the mixture under load conditions.

As far as I understand it, removing the cat code plug does not make the Moronic select a 'limp-home' mode; but merely a different fuel map - one of a least 6 programmed into it. Inside the beige (or whatever colour) box is just a jumper lead which connects (or not) two different contacts in the base of the unit. This selects the fuel map in use by the Moronic.

Hope this helps. Don't quote me: I know nowt compared to some of the elder statesmen here.

Bikergary · Dec 10, 2004

I got all excited, I could cure the surging by removing a plug. so with details of which one to remove, I lifted the seat..... opened the fuse box... Horror. It's not there.
Another plan out of the window, which has answered some questions as now I wonder why the plugs get so black.

Do I need to obtain another one of these plugs?

Steptoe · Dec 10, 2004

don't buy a plug - just use a jumper wire -

standard set-up wire goes to the left in the middle section, not the middle as shown ( or try it as in the picture for a nice surprise )

DanBkk · Dec 13, 2004

Does anyone know or know where I can find the 6 different jumper settings to select the different fuel maps? + details of what the different fuel maps do.

I'd like to make mine run a bit richer to eliminate surging, but it sounds like the map selected by removing the plug altogether may make it too rich.

I assume a different 'jumper' plug is fitted at manufacture to meet different countries emission regulations.

Steptoe - what does the setting you have in the pic do?

Cheers
Danbkk

Bikergary · Dec 20, 2004

Another idea failed .. :-(
I wired in a jumper like yours and.... it wouldn't start.
tried it in the others and again..... wouldn't run.
Spoke to my local garage, aparently not all 1100's had this (mine's a 98) solenoid, and it was generally used for restricting the bike (not sure on that though). apparently another possible cure is three prong spark plugs. not tried this yet.

cookie · Dec 20, 2004

not at all sure the links are the same on 1100 (motronic 2.2) as they are on the 1150 (2.4).

ps. when you change the link, you have to reset the TPS & clear the motronic memory. i have recently been told by someone who should know these things, that to clear the ECU config. files you have to remove fuse 5 for 5 minutes :confused:

taking out the motronic relay won't do it.

when powered up again, the ECU will rebuild the configs in line with link position, hardware etc.

roddy · Apr 27, 2005

Sorry

if this is dragging up a old subject.

I recently purchased a 99 1100GS that had bad surging between 3000-4000 rpm, and I tried the remove plug and reset the ECU trick and bugger me it works brilliant, at all rev's the bike response is superb, it's made a good bike better.

However you get nowt for nowt in this life, and since this is the first bike I've owned thats had injectors and all that malarky, so my question is what expensive component have I shorten'd the life of,

1. all that extra fuel can't do the CAT any good
2. the injetors
3. barrels
4. the bike failing the MOT on emmissoins
5. the whole bike
6. something I haven't thought of

cheers
Roddy

cookie · Apr 27, 2005

calm down, it'll all be fine

skywalker · Apr 27, 2005

roddy said:
Sorry if this is dragging up a old subject.

I recently purchased a 99 1100GS that had bad surging between 3000-4000 rpm, and I tried the remove plug and reset the ECU trick and bugger me it works brilliant, at all rev's the bike response is superb, it's made a good bike better.

However you get nowt for nowt in this life, and since this is the first bike I've owned thats had injectors and all that malarky, so my question is what expensive component have I shorten'd the life of,

1. all that extra fuel can't do the CAT any good
2. the injetors
3. barrels
4. the bike failing the MOT on emmissoins
5. the whole bike
6. something I haven't thought of

cheers
Roddy

None!!
Bikes are not subject to a co emission test for an mot.If however they are spewing thick black smoke ot of the exhaust like some of the buses here in the communist state of south yorkshire then it will probably fail

roddy · Apr 27, 2005

if bikes are except from the emissions test for a MOT, why do so many modern bikes have FI for emission control ?

just a thought

Roddy

Surging cured, but how?

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