Surging = fuelling issue?

[Steptoe]

Remember the old “Steptoe link”, the jumper lead in the cat code plug slot
Give it a go, costs nothing and takes 2 minutes.
It worked on thousands of bikes all those years ago

 

[MotoRevive]

He did the TPS more than once, which is why I think he's given up, concentrating on more modern and expensive BMWs.
Can I assume that richer fueling won't have a detrimental effect on the GS? I guess my other question is, is surging a lean fuelling issue?

Yeah. But what is "DID THE TPS" ? You can find a lot of excellent mechanics who completely fall over when you start talking about TPS voltages.

I'm not saying your guy is incompetent. But perhaps a fresh set of eyes could help. Every mechanic/Tech has their strengths and weaknesses.

It might be worth tracking down another TPS. Yours will be old now. And they do fail. And it's often difficult to see using a meter.


Read this until your eyes bleed. Then read it again.

TPS Alignment, Idle Speed Adjustment: Beyond Zero=Zero

Although I'm not a fan of adjusting the throttle stop screws or TPS, since they're factory calibrated (mine are untouched and are in spec). Many motorcycles have already been altered using the zero=zero procedure (and there may be wear beyond adjustable BBS limits) creating a need to restore...

forums.bmwmoa.org

But scroll down to the BMW procedure. Because Roger does waffle on needlessly and over complicates things.

He does say "zero-zero" is incorrect. And if you stick to the book, he's right. They say zero-250. But BMW want the bike lean for emissions. We want them the best they can be for power and health. Which I believe works better at zero-zero.



Remember. Tuning a bike is dependent on EVERYTHING being correct first. It's literally the last thing you do. You need excellent compression, valves in spec, good plugs, healthy coils, good fuel pressure etc.

Otherwise you're just chasing your tail.

 

[Steve B]

Remember the old “Steptoe link”, the jumper lead in the cat code plug slot
Give it a go, costs nothing and takes 2 minutes.
It worked on thousands of bikes all those years ago

Thanks Neil. I remember this from days of yore. I'll give it a go. As I mentioned, I guess it's a process of elimination

 

[Steve B]

Yeah. But what is "DID THE TPS" ? You can find a lot of excellent mechanics who completely fall over when you start talking about TPS voltages.

I'm not saying your guy is incompetent. But perhaps a fresh set of eyes could help. Every mechanic/Tech has their strengths and weaknesses.

It might be worth tracking down another TPS. Yours will be old now. And they do fail. And it's often difficult to see using a meter.


Read this until your eyes bleed. Then read it again.

TPS Alignment, Idle Speed Adjustment: Beyond Zero=Zero

Although I'm not a fan of adjusting the throttle stop screws or TPS, since they're factory calibrated (mine are untouched and are in spec). Many motorcycles have already been altered using the zero=zero procedure (and there may be wear beyond adjustable BBS limits) creating a need to restore...

forums.bmwmoa.org

But scroll down to the BMW procedure. Because Roger does waffle on needlessly and over complicates things.

He does say "zero-zero" is incorrect. And if you stick to the book, he's right. They say zero-250. But BMW want the bike lean for emissions. We want them the best they can be for power and health. Which I believe works better at zero-zero.



Remember. Tuning a bike is dependent on EVERYTHING being correct first. It's literally the last thing you do. You need excellent compression, valves in spec, good plugs, healthy coils, good fuel pressure etc.

Otherwise you're just chasing your tail.

Many thanks for this mate As you say, it is a matter of having everything correct along the process and in order.

 

[Steve B]

I recall many years ago on my way back from France I fuelled up with 98 octane from a Supermarket, I usually run the bike on 95 octane as well as set it up at servicing. Anyway the bike was surging like a bastard and was really hard to handle, I was sweating whether I would make the shuttle or not. It wasn’t until I refuelled with 95 back in England that the surging disappeared and the bike settled down.

Thanks for this Ian. I tend to fill the GS with E5 due to the issue of more moisture in E10.

 

[Steve B]

Remember the old “Steptoe link”, the jumper lead in the cat code plug slot
Give it a go, costs nothing and takes 2 minutes.
It worked on thousands of bikes all those years ago

Can you confirm whether doing this cat code change is specifically for non-standard set-ups? I've just spent a couple of hours trying to find your original post, but in the end, read every other post on cat code changes.
My GS still has its cat and has a stubby pipe, so I'm unsure if there is a specific jumper lead for basic bikes, not decatted, aftermarket pipes etc.

 

[Wrigsby1]

And before entering the web of different "surging fixes" the 1100 scenario and 1150 are different...
1100 were/are open loop, an early version of Moronic and prone to snatchy on off throttle due to this and being poorly set up... 1150 surging was usually an experience of the Lambda leaning off the fuelling...
Obviously it sounds like several bits have been worked on already and if it's happened fairly suddenly, then something has changed... I take it the twin spark fave of dodgy Coilpacks has been checked and you have to be careful for doing multiple fixes at once and ending up more confused than you started...
There's loads of advice on here but also loads of scenarios so trying to understand yours first is the main thing rather than fixing/ changing things that weren't the problem...

 

[Steve B]

And before entering the web of different "surging fixes" the 1100 scenario and 1150 are different...
1100 were/are open loop, an early version of Moronic and prone to snatchy on off throttle due to this and being poorly set up... 1150 surging was usually an experience of the Lambda leaning off the fuelling...
Obviously it sounds like several bits have been worked on already and if it's happened fairly suddenly, then something has changed... I take it the twin spark fave of dodgy Coilpacks has been checked and you have to be careful for doing multiple fixes at once and ending up more confused than you started...
There's loads of advice on here but also loads of scenarios so trying to understand yours first is the main thing rather than fixing/ changing things that weren't the problem...

Thanks for all the logical points to consider.
The surging did come on gradually. Coil packs haven't been done, or checked, as far as I'm aware so something else to eliminate.
Can I assume then (as an ignorant bystander), that 1150 surging is to do with the fuelling running lean? Just curious.

 

[Nick Marshall]

Coil packs is what I meant by plug caps.
Same thing. They connect to the spark plugs.

They have been known to fall apart.

 

[Wrigsby1]

Thanks for all the logical points to consider.
The surging did come on gradually. Coil packs haven't been done, or checked, as far as I'm aware so something else to eliminate.
Can I assume then (as an ignorant bystander), that 1150 surging is to do with the fuelling running lean? Just curious.

Sadly the only way to really know is for another experienced GSer to have a run on the bike... There so many different reports of "Surging"... The Coilpacks are a well known failure and can be intermittent...

 

[MotoRevive]

Thanks for all the logical points to consider.
The surging did come on gradually. Coil packs haven't been done, or checked, as far as I'm aware so something else to eliminate.
Can I assume then (as an ignorant bystander), that 1150 surging is to do with the fuelling running lean? Just curious.

Surging can mean a lot of things. And be caused by a lot of things too. It all depends on your definition.

 

[Wrigsby1]

Thanks for all the logical points to consider.
The surging did come on gradually. Coil packs haven't been done, or checked, as far as I'm aware so something else to eliminate.
Can I assume then (as an ignorant bystander), that 1150 surging is to do with the fuelling running lean? Just curious.

Just as a heads up to the "type you're thinking of... I sold BMs for a couple of years either side of the single/ twin spark... The witter at the time was that on a constant throttle let's say 70 cruising, these early Lambda bikes would feel like they were slowing slightly then speeding up as you put pressure on the throttle... The theory was the lambda effect on constant throttle would lean off a little, obviously richening when you accelerated a slight amount. I never really noticed it on the many bikes I rode...
The twin spark idea was probably as much to do with getting an extra couple of years out of the Oilhead design with emissions/ smoothness etc and even though we cooed about it at the time, was probably much the same... In fact it introduced a couple of extra probs with failing Coilpacks in time...
The "other" main surging was just a badly set up bike injector wise... 1100s not including the S didn't have a lambda in the UK and an earlier motronic and injector set up so could be anything from a lively kangaroo to a pussy cat depending on setting up... The difference in the later bikes were very noticeable...

Strangely one of the sweetest oilheads I rode was a 99 1100RT...

 

[Steve B]

Coil packs is what I meant by plug caps.
Same thing. They connect to the spark plugs.

They have been known to fall apart.

I'd guessed that's what you meant Nick. Had to replace 2 on my previous GS years ago and they weren't cheap then

 

[Steve B]

Sadly the only way to really know is for another experienced GSer to have a run on the bike... There so many different reports of "Surging"... The Coilpacks are a well known failure and can be intermittent...

Good point. Don't know anyone in my area, but at low speeds, it is definitely there to feel something isn't right with the fuelling.
I'll try the cheap workaround of Mr Steptoe's Cat code plug wire (if I can actually find the photo ).
Anyone know what coil packs are going for these days? I was shocked at the prices in the early noughties when I had to have 2 replaced.

 

[Steve B]

Surging can mean a lot of things. And be caused by a lot of things too. It all depends on your definition.

As Wrigsby1 has suggested, best that someone else rides the bike to see how bad it is or whether it's something else (my imagination). I rode my last GS for 13 years, and it is chalk and cheese compared to this GS.

 

[Steve B]

Just as a heads up to the "type you're thinking of... I sold BMs for a couple of years either side of the single/ twin spark... The witter at the time was that on a constant throttle let's say 70 cruising, these early Lambda bikes would feel like they were slowing slightly then speeding up as you put pressure on the throttle... The theory was the lambda effect on constant throttle would lean off a little, obviously richening when you accelerated a slight amount. I never really noticed it on the many bikes I rode...
The twin spark idea was probably as much to do with getting an extra couple of years out of the Oilhead design with emissions/ smoothness etc and even though we cooed about it at the time, was probably much the same... In fact it introduced a couple of extra probs with failing Coilpacks in time...
The "other" main surging was just a badly set up bike injector wise... 1100s not including the S didn't have a lambda in the UK and an earlier motronic and injector set up so could be anything from a lively kangaroo to a pussy cat depending on setting up... The difference in the later bikes were very noticeable...

Strangely one of the sweetest oilheads I rode was a 99 1100RT...

I guess my frustration is that it didn't have the surging when I bought it (from a very reliable member of the forum) and after 2 visits to an ex-BMW mechanic, I am no further in getting it resolved. The issue spoiled what should have been a good trip around France and Belgium. I just spent my time swearing in my helmet. I might put it in with an 'expert' mechanic to do whatever needs to be done.

 

[JohnnyBoxer]

Good point. Don't know anyone in my area, but at low speeds, it is definitely there to feel something isn't right with the fuelling.
I'll try the cheap workaround of Mr Steptoe's Cat code plug wire (if I can actually find the photo ).
Anyone know what coil packs are going for these days? I was shocked at the prices in the early noughties when I had to have 2 replaced.

Maybe £100+++ each nowadays
Bought some a couple of years ago and decided to buy genuine BMW (instead of eBay copies) as they were the real deal and came with a 2 year warranty

 

[JohnnyBoxer]

I guess my frustration is that it didn't have the surging when I bought it (from a very reliable member of the forum) and after 2 visits to an ex-BMW mechanic, I am no further in getting it resolved. The issue spoiled what should have been a good trip around France and Belgium. I just spent my time swearing in my helmet. I might put it in with an 'expert' mechanic to do whatever needs to be done.

Have a weekend away in north Lincolnshire and Go to see Steve at Rainbow Workshop
He’s an ex BMW Motorrad mechanic and service manager
He specialises in and loves 1150 GS’s

 

[rustychain]

Can you confirm whether doing this cat code change is specifically for non-standard set-ups? I've just spent a couple of hours trying to find your original post, but in the end, read every other post on cat code changes.
My GS still has its cat and has a stubby pipe, so I'm unsure if there is a specific jumper lead for basic bikes, not decatted, aftermarket pipes etc.

Here's the original post in case you're still looking for it:

Thread 'cat code plug (AKA STEPTOE's LINK)'

Sep 21, 2004

For those that have fitted Y pieces have you

EDIT...Moved from Poll dancers to Font of all wisdom to make this thread easier to find.....Down Tarka!
Bill

• Keith Chapman
• Replies: 142
• Forum: The font of all wisdom

 

[Two wheels good]

I don't see any mention of:
Remove Fuse 5 for a few hours to reset the ECU.

I'm dealing with some low speed surging for the first time at the moment. High mileage 02 single spark.
Doubly frustrating because I was still enjoy the novelty of the improvement brought by the fitment of new R1200 injectors a few months ago