Throttle balance TPS..

[Fir Cologne]

Hi Y'all 97 GS1100 170,00K's.

I've got quite a story... Couple years ago bike wouldn't idle, only on 'choke'.

I didn't know much about these bikes then, but found 'blocking out' the butterfly screw with a piece of inner tube fixed it.

The screws that they say "don't touch", I touched.

Got myself in a fine mess.

Turns out the screw was stripped, got a new screw, but replaced the cables, coils, leads HES, TPS, sonic cleaned injectors, fuel pump, all the internal, and external fuel lines...

So, took it into a guy, He threw out my NEW TPS and put the old one back on, Grr. He got it going, but set TPS according to diagnostic reader.

The problem with that, it was gutless, had no rev range, and a big dead spot.

So I tinkered with it some more, set the TPS back down. Still couldn't get it to run right..

So took it to another guy (BMW Indie), He just replaced the throttle bodies, and set the TPS as above...

So this is all history, I've read extensively on the TPS settings, and done the zero-250 100 times.

I had an oil leak from the RHS, so I had the heads reconditioned, 1 valve was slightly bent at the collet, no impact damage, and didn't affect running.

I balance the throttles on a home made manometer, length of tube with ATF.

My problem is I can't get it to balance, and I get dead spots which move up and down the range according to the TPS settings.

The last thing I did, I slacked the cables (single cable, no Bowden box) right off, set the 0-250-360 and tried to match the other side.

The problem is, the BBS bypass screw can be closed on the RHS and 2 turns open on the left to get that final balance.

At the moment it's running okay, I have it as balanced as I can get it, and it has only a slight hesitation at 4000RPM (crossover sweeps of TPs?)

I realise this is  a bit complex so Isle stick to a couple questions.

I think; when I set LHS Throttle plate, it's not turned out enough for the RHS to be able to match it, and I think the RHS has been held open with the cable?

I've tried the 0-360, but that sets idle way to high.

How can it run with BBS closed? Is air getting around the butterfly, Is the cable holding it open, at the expense of the screw adjustment?

I don't understand about initial throttle plate angle, what is the adjustment? They close by spring action, and it's the throttle screws which dictate the opening at idle, yes/no?

(I read a few stories about people checking the angle of the butterfly).

It's going 'okay' at the moment, could definitely run better.

The dead spot,which ranges up or down depending on TPS settings ( I was just resetting the TPS, not doing full 0-0), Is that a faulty TPS, I be angry if it is, they're $400 new.

I was thinking it was where 1 sweep finishes, and the secondary sweep starts, that lag in between?

Or is it throttle balance which causes the dead spot? i have it almost tuned out, just a stumble at 4000rpm now?

I'm gunner pull it all down again shortly, slacken the cables right off, set the throttle plate screws, the 0-25o-360, then do the cables, again...

Sorry if this reads a bit disjointed, it's been ongoing for 2-3 years, and I'm not giving it back to the shop, Isle do it myself, just need to understand a few things.

I've been on other forums and they've just taken the piss, I'm just a guy trying to get my bike to run.

I have the original TB's, both sets are in good condition, shafts seem ok.

I've considered rebuilding the TB's, or sending them back the Bing to be bench tested ad reset, but don't really have the budget, and I'm determined to fix this myself..

Thanks Y'all from Western Australia, sunshine and blue seas all day!

 

 

[dirtrider]

4 hours ago, Fir Cologne said:

Hi Y'all 97 GS1100 170,00K's.

I've got quite a story... Couple years ago bike wouldn't idle, only on 'choke'.

I didn't know much about these bikes then, but found 'blocking out' the butterfly screw with a piece of inner tube fixed it.

The screws that they say "don't touch", I touched.

Got myself in a fine mess.

Turns out the screw was stripped, got a new screw, but replaced the cables, coils, leads HES, TPS, sonic cleaned injectors, fuel pump, all the internal, and external fuel lines...

So, took it into a guy, He threw out my NEW TPS and put the old one back on, Grr. He got it going, but set TPS according to diagnostic reader.

The problem with that, it was gutless, had no rev range, and a big dead spot.

So I tinkered with it some more, set the TPS back down. Still couldn't get it to run right..

So took it to another guy (BMW Indie), He just replaced the throttle bodies, and set the TPS as above...

So this is all history, I've read extensively on the TPS settings, and done the zero-250 100 times.

I had an oil leak from the RHS, so I had the heads reconditioned, 1 valve was slightly bent at the collet, no impact damage, and didn't affect running.

I balance the throttles on a home made manometer, length of tube with ATF.

My problem is I can't get it to balance, and I get dead spots which move up and down the range according to the TPS settings.

The last thing I did, I slacked the cables (single cable, no Bowden box) right off, set the 0-250-360 and tried to match the other side.

The problem is, the BBS bypass screw can be closed on the RHS and 2 turns open on the left to get that final balance.

At the moment it's running okay, I have it as balanced as I can get it, and it has only a slight hesitation at 4000RPM (crossover sweeps of TPs?)

I realise this is  a bit complex so Isle stick to a couple questions.

I think; when I set LHS Throttle plate, it's not turned out enough for the RHS to be able to match it, and I think the RHS has been held open with the cable?

I've tried the 0-360, but that sets idle way to high.

How can it run with BBS closed? Is air getting around the butterfly, Is the cable holding it open, at the expense of the screw adjustment?

I don't understand about initial throttle plate angle, what is the adjustment? They close by spring action, and it's the throttle screws which dictate the opening at idle, yes/no?

(I read a few stories about people checking the angle of the butterfly).

It's going 'okay' at the moment, could definitely run better.

The dead spot,which ranges up or down depending on TPS settings ( I was just resetting the TPS, not doing full 0-0), Is that a faulty TPS, I be angry if it is, they're $400 new.

I was thinking it was where 1 sweep finishes, and the secondary sweep starts, that lag in between?

Or is it throttle balance which causes the dead spot? i have it almost tuned out, just a stumble at 4000rpm now?

I'm gunner pull it all down again shortly, slacken the cables right off, set the throttle plate screws, the 0-25o-360, then do the cables, again...

Sorry if this reads a bit disjointed, it's been ongoing for 2-3 years, and I'm not giving it back to the shop, Isle do it myself, just need to understand a few things.

I've been on other forums and they've just taken the piss, I'm just a guy trying to get my bike to run.

I have the original TB's, both sets are in good condition, shafts seem ok.

I've considered rebuilding the TB's, or sending them back the Bing to be bench tested ad reset, but don't really have the budget, and I'm determined to fix this myself..

Thanks Y'all from Western Australia, sunshine and blue seas all day!

 

 

Morning  Fir Cologne

 

You have a LOT going on there & keep blaming the TPS for most of it? 

 

So lets start from a clean slate & work up from there. 

 

Did your 1100GS come with an o2 sensor from the factory? If so is it still connected & operational?

 

Does you motorcycle still have the original CCP in the fuse box. 

 

These are the basics but the above does effect what we need to look at & work with. 

 

At what throttle openings does you flat spot appear (not RPM but actual throttle opening position, like 1/4 throttle or 1/2 throttle or 3/4 throttle, or WOT? 

 

Does it always happen at about the same throttle opening? Or at about  the same engine RPM?

 

How about the gear that it is in? Always in the same gear or in different gears?

 

The answers to the above above will hopefully give us a baseline to work from.

 

 

 

 

 

[dirtrider]

More on your basic questions______

 

I think; when I set LHS Throttle plate, it's not turned out enough for the RHS to be able to match it, and I think the RHS has been held open with the cable?-- This can happen on the single cable systems, the crossover cable changes length with temperature & wear so getting a good balance at ALL throttle positions is about impossible. At higher throttle openings the balance is not as critical as at lower openings so get it as close as possible at just above idle (1/8-1/4 throttle opening). The R/H side should just about hang on the crossover cable not on the base idle screw or the right side won't open in unison with the L/H side (if set correctly the R/H side should not even need a base idle screw on a hot engine)

  

Just keep in mind that if the single cable system worked perfectly then BMW would not have updated it to the split cable bowden box system.

 

 

I've tried the 0-360, but that sets idle way to high.-- Yes WAY too high.

 

How can it run with BBS closed? Is air getting around the butterfly, Is the cable holding it open, at the expense of the screw adjustment?-- Possibly both,  the throttle plates never seal completely so some air gets around them (especially on higher mile bikes with worn throttle plates & worn throttle shafts with worn throttle shaft bushings. Also, on the single cable systems the crossover cable can easily hold the R/H throttle plate open.  Are both side TB vacuum nipples plugged off with GOOD vacuum caps?

 

I don't understand about initial throttle plate angle, what is the adjustment?-- There is no SERVICE adjustment, that is originally set at the TB supplier (Bing). About the only (non approved) service is to set them to get a decent cross-side balance, with the correct idle RPM, & with the BBS screws set in the ball park of 1-1/2 turns out from seated.  The older & the more miles  on the motorcycle then the more give & take required to get that adjustment anywhere close.  (the just-above-idle is the most important, or more critical, as the air flow in that range is less per degree of plate opening)

 

They close by spring action, and it's the throttle screws which dictate the opening at idle, yes/no?-- Yes AND no, with no throttle cables hooked up the base idle screws do control the throttle plate base opening. On the single cable systems then the crossover cable can easily control the R/H side base throttle plate opening.  

 

(I read a few stories about people checking the angle of the butterfly).-- Why bother? What does it matter if they don't even know what angle  it is supposed to be?????? With a higher mile  worn throttle plates, or worn throttle shaft, or worn bushings the base air flow will still be off even if the plate angle was somehow set correctly. Then even IF all is correct that all goes to hell if the crossover cable holds the R/H side open a bit more at hot curb idle.  

 

It's going 'okay' at the moment, could definitely run better.-- Probably some other problem than the throttle bodies or TPS.

 

 

The dead spot, which ranges up or down depending on TPS settings ( I was just resetting the TPS, not doing full 0-0), Is that a faulty TPS, I be angry if it is, they're $400 new.-- No way to know without substituting a known good TPS or totally tracking your present TPS on both it's outputs. (your flat spot might very well not be related to the TPS) 

 

I was thinking it was where 1 sweep finishes, and the secondary sweep starts, that lag in between?-- Doubtful as they overlap.

 

Or is it throttle balance which causes the dead spot? i have it almost tuned out, just a stumble at 4000rpm now?-- At 4000 RPM, under road load, the balance would have to be WAY/WAY off to give you a flat spot (probably something else causing the flat spot)

 

I'm gunner pull it all down again shortly, slacken the cables right off, set the throttle plate screws, the 0-25o-360, then do the cables, again...-- Find the problem FIRST, just get the TB balance close at just above idle, set the TPS to about .385 volts at choke-off & closed throttle, then if it still acts up  find the problem with something else. (what CCP are you using?????)

 

Sorry if this reads a bit disjointed, it's been ongoing for 2-3 years, and I'm not giving it back to the shop, Isle do it myself, just need to understand a few things.-- You need to try to set EVERYTHING back to stock  then start over with a compression test, fuel pressure test & fuel flow test, exhaust backpressure test, TPS tracking test, cam timing check, etc. 

 

I've been on other forums and they've just taken the piss, I'm just a guy trying to get my bike to run.-- Difficult to tell from this far away but you need to quit fixating on JUST the TPS & throttle balance. Especially if all your work with those have not made it run any better!!!!!

 

I have the original TB's, both sets are in good condition, shafts seem ok.-- Seem OK or ARE OK???

 

I've considered rebuilding the TB's, or sending them back the Bing to be bench tested ad reset, -- Are you sure BING will even do that? BING USA won't. 

 

I'm determined to fix this myself..-- You need to change your goal, start by first  determining what is wrong with it. You can't effectively FIX IT if you don't know exactly what is causing the problem.  Are your fuel injectors working correctly??? (have they been tested by a real injector shop???__ Is your fuel pressure & fuel flow up to standards?????_  Is your camshaft timing correct???_ Is your exhaust flowing with no backpressure???_ Is your intake restricted (have you run it with no air filter in place????_  Are the backs of you intake or exhaust valves coked  up & restricting flow??? 

 

If your motorcycle has an o2 sensor try running with it disconnected. Or try removing the CCP then riding it.

 

Added: NEVER/ever use the choke before setting the balance on a single cable system as that skews the crossover cable tracking on the L/H side TB cam.  Fully open & close the throttle 10 times with choke off before making any cable adjustments on the single cable system (this properly seats the cable tracking on the L/H side. 

 

You also want the engine hot (to heat the crossover cable) as it changes length with temperature. 

 

 

 

 

[Fir Cologne]

Thanks for your insights, food for thought. CCP relay, good point.

Has C02 Pot, no O2 sensor.

Open exhaust, staintune, no cat

New, balanced (1200) Injectors. New coils, leads, HES.

Heads had valve grind very recently.

The dead spot usally is about 4000rp , throttling on to pass a car, yikes. It's almost imperceptable atm, that's what I've been basing the TPS scenario on... I do't think it's dependamt on any gear, just more noticeable in 5th.

I have the worn dogs on the gearbox, so it'll give tha little lurch in top, but unrelated, I'll get a new gearbox, if I don't outlive this.

Compressions are a bit off 80-90 vs 90-100.

I've had the airbox out, fitted cone filters, but gone back to airbox, TB's are clean as BBS also.

I won't comment further, Isle try it without the CCP relay and report back.

As you can tell, I'm just an amateur, and I don't want to take this into a shop, they'd go on a fishing expedition at $140 an hour.

Has new cam chain tensioners, both sides also, had the heads off it, but pretty sue the cam chains were tied back and went back on correctly.

Should've done the rings while I had the heads away, the bore is perfect, still crosshatched, and rings are sharp, so we left it.

Cables are new, quite possible they are holding open the RH throttle, I'm adjusting it at the crossover on the LHS as I've run out of adjustment on RHS.

I set the balance just off idle, about 2000RPM (as well as idle).

I have the original TB's, They seem okay, I could rebuild them, but they not loose at all, I could swap them back, see if that makes a difference, but the dead spot problem carried over from 1 set to the next.

Anyway, appreciated, enough for now, I'll take it for a run without the CCP relay.

Chers

 

[dirtrider]

Morning Fir Cologne

 

Yes, definitely try riding with the CCP removed, but with no o2 sensor it probably won't make a lot of difference unless you somehow now have the low-octane CCP in that motorcycle. 

 

Compressions are a bit off 80-90 vs 90-100.---  Is that 80-90  on one side & 90-100 on the other side? If so the side to side isn't that far off but they are low. Was that done with the throttles held wide open & fuse #5 removed? Is your engine cranking speed up to specs? A that low it is usually low cranking speed or lack of intake air to compress.

How many piston up's (compression puffs) does take to get max PSI compression on each side??? If the same then compression just low, if one side takes many more puffs to reach max than the other then you have problems to find. Try running each side to 4 compression puffs THEN see what your compression is side to side.

 

Has new cam chain tensioners, both sides also, had the heads off it, but pretty suer the cam chains were tied back and went back on correctly.---  That only accounts for the chain to sprocket part of the timing, is the sprocket bolted on the camshaft correctly???? Is is not that difficult to have the sprocket get mis-aligned while tightening the retaining bolt therefore crushing the sprocket alignment tit. (but if your cranking compression is NOW within 10 lbs of each other side to side then that is a lower concern than it was with your old original compression readings)  

 

If your problem is at 4000 RPM's then why do you keep fooling around balancing at 2000 RPM's?  Go ride that motorcycle at the speed & RPM that you are seeing the issue then MARK the twist grip to housing at THAT throttle opening with a marker, or tape with ink pen lines. Then check your balance at THAT throttle opening. Don't mess with the idle balance or just above idle until you get it to balance in the problem throttle opening range. You also need to CAREFULLY  check that BOTH side throttle cams hit the wide open throttle stops at the VERY SAME TIME if one side hits earlier than the other then find THAT problem.

 

You also need to verify that you have enough return fuel flowing at that engine RPM & load. This verifies that you enough fuel pressure at enough flow to make full power at that 4000 RPM's under road load. If you have a wimpy fuel return flow then it is very possibly going lean at 4K under road load. 

[Fir Cologne]

 

I went for a ride yesterday, didn't touch the code plug or anything, thinking about my assumptions.

I think it's running lean in the higher revs, which gives me that lag from cruising to acceleration, like passing cars.

Another factor I'm not sure about; adjusting the C02 pot, I don't have the gizmo's for testing that, can I play with it? turn it in or out a turn, see if it makes a difference?

And the coding plug, can I just run without it, I don't need to reset motronic or anything?

Compression, it's not accurate, just a press in gauge, but it has plenty, It will lock up the rear wheel if you cut down to 2nd.

I have done all the tank internals, new fuel pump, filters, hoses.

The cam sprockets went back on fine, I don't see any issue there...

I don't have much time atm, but taking this on board for when I do get time.

Thanks again

 

 

Thanks for your insights, food for thought. CCP relay, good point.

Has C02 Pot, no O2 sensor.

Open exhaust, staintune, no cat

New, balanced (1200) Injectors. New coils, leads, HES.

Heads had valve grind very recently.

The dead spot usally is about 4000rp , throttling on to pass a car, yikes. It's almost imperceptable atm, that's what I've been basing the TPS scenario on... I do't think it's dependamt on any gear, just more noticeable in 5th.

I have the worn dogs on the gearbox, so it'll give tha little lurch in top, but unrelated, I'll get a new gearbox, if I don't outlive this.

Compressions are a bit off 80-90 vs 90-100.

I've had the airbox out, fitted cone filters, but gone back to airbox, TB's are clean as BBS also.

I won't comment further, Isle try it without the CCP relay and report back.

As you can tell, I'm just an amateur, and I don't want to take this into a shop, they'd go on a fishing expedition at $140 an hour.

Has new cam chain tensioners, both sides also, had the heads off it, but pretty sue the cam chains were tied back and went back on correctly.

Should've done the rings while I had the heads away, the bore is perfect, still crosshatched, and rings are sharp, so we left it.

Cables are new, quite possible they are holding open the RH throttle, I'm adjusting it at the crossover on the LHS as I've run out of adjustment on RHS.

I set the balance just off idle, about 2000RPM (as well as idle).

I have the original TB's, They seem okay, I could rebuild them, but they not loose at all, I could swap them back, see if that makes a difference, but the dead spot problem carried over from 1 set to the next.

Anyway, appreciated, enough for now, I'll take it for a run without the CCP relay.

Chers

 

[dirtrider]

Morning    Fir Cologne                                                                                                                                                                                                                                     

 

I think it's running lean in the higher revs, which gives me that lag from cruising to acceleration, like passing cars.

Another factor I'm not sure about; adjusting the C02 pot, I don't have the gizmo's for testing that, can I play with it? turn it in or out a turn, see if it makes a difference?--  The Co pot has little effect below 1/2 throttle, & no effect above 1/2 throttle as it is mainly an IDLE Co adjuster for emission compliance. The Co pot adjustment isn't your issue at 4000 RPM's. 

 

And the coding plug, can I just run without it, I don't need to reset motronic or anything?-- No need to reset anything just pop it out. 

 

The dead spot usally is about 4000rp , throttling on to pass a car, yikes. It's almost imperceptable atm, that's what I've been basing the TPS scenario on... I do't think it's dependamt on any gear, just more noticeable in 5th.-- Mark the twist grip position the see if the problem always happens at the same throttle twist grip position.   

 

I set the balance just off idle, about 2000RPM (as well as idle)--  Mark the throttle twist grip position at the point the problem happens, then check your TB balance & TPS sweeps at that throttle (twist grip) position. If you problem doesn't happen at idle then quit messing with the idle balance (check it at the throttle opening that the problem is happening at)

 

I have the original TB's, They seem okay, I could rebuild them, but they not loose at all, I could swap them back, see if that makes a difference, but the dead spot problem carried over from 1 set to the next.-- Throttle bodies are open quite a ways at 4000 RPM's road load so it would be a very long shot that those are the problem. If they are off far enough at 4000 RPM's then they would be WAY/WAY off at lower throttle openings  & that would be very obvious in the lower speed engine throttle control.  

 

[Fir Cologne]

 

Seems there is no coding plug, I'm working ridiculous hours atm, will follow this up when I can...

 

I went for a ride yesterday, didn't touch the code plug or anything, thinking about my assumptions.

I think it's running lean in the higher revs, which gives me that lag from cruising to acceleration, like passing cars.

Another factor I'm not sure about; adjusting the C02 pot, I don't have the gizmo's for testing that, can I play with it? turn it in or out a turn, see if it makes a difference?

And the coding plug, can I just run without it, I don't need to reset motronic or anything?

Compression, it's not accurate, just a press in gauge, but it has plenty, It will lock up the rear wheel if you cut down to 2nd.

I have done all the tank internals, new fuel pump, filters, hoses.

The cam sprockets went back on fine, I don't see any issue there...

I don't have much time atm, but taking this on board for when I do get time.

Thanks again

 

 

Thanks for your insights, food for thought. CCP relay, good point.

Has C02 Pot, no O2 sensor.

Open exhaust, staintune, no cat

New, balanced (1200) Injectors. New coils, leads, HES.

Heads had valve grind very recently.

The dead spot usally is about 4000rp , throttling on to pass a car, yikes. It's almost imperceptable atm, that's what I've been basing the TPS scenario on... I do't think it's dependamt on any gear, just more noticeable in 5th.

I have the worn dogs on the gearbox, so it'll give tha little lurch in top, but unrelated, I'll get a new gearbox, if I don't outlive this.

Compressions are a bit off 80-90 vs 90-100.

I've had the airbox out, fitted cone filters, but gone back to airbox, TB's are clean as BBS also.

I won't comment further, Isle try it without the CCP relay and report back.

As you can tell, I'm just an amateur, and I don't want to take this into a shop, they'd go on a fishing expedition at $140 an hour.

Has new cam chain tensioners, both sides also, had the heads off it, but pretty sue the cam chains were tied back and went back on correctly.

Should've done the rings while I had the heads away, the bore is perfect, still crosshatched, and rings are sharp, so we left it.

Cables are new, quite possible they are holding open the RH throttle, I'm adjusting it at the crossover on the LHS as I've run out of adjustment on RHS.

I set the balance just off idle, about 2000RPM (as well as idle).

I have the original TB's, They seem okay, I could rebuild them, but they not loose at all, I could swap them back, see if that makes a difference, but the dead spot problem carried over from 1 set to the next.

Anyway, appreciated, enough for now, I'll take it for a run without the CCP relay.

Chers

 

[dirtrider]

12 hours ago, Fir Cologne said:

 

Seems there is no coding plug, I'm working ridiculous hours atm, will follow this up when I can...

 

I went for a ride yesterday, didn't touch the code plug or anything, thinking about my assumptions.

I think it's running lean in the higher revs, which gives me that lag from cruising to acceleration, like passing cars.

Another factor I'm not sure about; adjusting the C02 pot, I don't have the gizmo's for testing that, can I play with it? turn it in or out a turn, see if it makes a difference?

And the coding plug, can I just run without it, I don't need to reset motronic or anything?

Compression, it's not accurate, just a press in gauge, but it has plenty, It will lock up the rear wheel if you cut down to 2nd.

I have done all the tank internals, new fuel pump, filters, hoses.

The cam sprockets went back on fine, I don't see any issue there...

I don't have much time atm, but taking this on board for when I do get time.

Thanks again

 

 

Thanks for your insights, food for thought. CCP relay, good point.

Has no O2 sensor.

Open exhaust, staintune, no cat

New, balanced (1200) Injectors. New coils, leads, HES.

Heads had valve grind very recently.

The dead spot usally is about 4000rp , throttling on to pass a car, yikes. It's almost imperceptable atm, that's what I've been basing the TPS scenario on... I do't think it's dependamt on any gear, just more noticeable in 5th.

I have the worn dogs on the gearbox, so it'll give tha little lurch in top, but unrelated, I'll get a new gearbox, if I don't outlive this.

Compressions are a bit off 80-90 vs 90-100.

I've had the airbox out, fitted cone filters, but gone back to airbox, TB's are clean as BBS also.

I won't comment further, Isle try it without the CCP relay and report back.

As you can tell, I'm just an amateur, and I don't want to take this into a shop, they'd go on a fishing expedition at $140 an hour.

Has new cam chain tensioners, both sides also, had the heads off it, but pretty sue the cam chains were tied back and went back on correctly.

Should've done the rings while I had the heads away, the bore is perfect, still crosshatched, and rings are sharp, so we left it.

Cables are new, quite possible they are holding open the RH throttle, I'm adjusting it at the crossover on the LHS as I've run out of adjustment on RHS.

I set the balance just off idle, about 2000RPM (as well as idle).

I have the original TB's, They seem okay, I could rebuild them, but they not loose at all, I could swap them back, see if that makes a difference, but the dead spot problem carried over from 1 set to the next.

Anyway, appreciated, enough for now, I'll take it for a run without the CCP relay.

Chers

 

Morning    Fir Cologne 

 

With no CCP coding plug in that motorcycle just unplug the Co Pot, (idle trim Pot), that will drive the fueling as rich as it will get, just keep in mind that it is an IDLE trim pot so really doesn't effect the fueling after about 1/4 throttle opening.  You can ride it as long as you want with the  Co trim pot disconnected (we used to do that for full motorcycle life here in the U.S.)  

 

If you think it is running lean then just do a good "return fuel flow test", if you get a nice pencil-sized return flow with engine running  then you have enough fuel pressure to open the pressure regulator, & have enough fuel  flow to run it out to top speed.

 

I still don't get the reason that you are fooling with the 2000 RPM balance when your problem is at 4000 RPM's??????????? 

 

An open exhaust probably doesn't help the problem as with no cat your are probably getting a little (maybe a lot) of exhaust reversion at 4000 RPM's

 

[Fir Cologne]

Thanks for your time, I'm following as best I can.

Following an old post I found, with yourself and Roger 04, interesting thoughts about the TPS, disconnecting it from TB as you set up the stops etc.

Seems there is no coding plug, I'm working ridiculous hours atm, will follow this up when I can...

I had a little tinker, and checked the TPS settings, it was 255, I adjusted it down a few points, to 150, and the lag, the dead spot has dropped to 2500-3000RPM.

I'm not starting anything major atm, but the easiest thing I can do is change out the TPS, eliminate that.

I'm reluctant to shell out another $400, but a Go-ogle search came back witht he same part number for a range of vehicles, not at BMW prices.. Throttle Position Sensor (Bosch 0 280 122 201).

The more I read, the more I understand this, which is all I'm doing atm.

Slightly off topic, ever since I've had my heads reconditioned I get a lot of backfire, crackle and pop?  

I suspect this is related, as previous endeavours with TPS settings tend to increase the pop-crackle.

Thanks again.  

 

I went for a ride yesterday, didn't touch the code plug or anything, thinking about my assumptions.

I think it's running lean in the higher revs, which gives me that lag from cruising to acceleration, like passing cars.

Another factor I'm not sure about; adjusting the C02 pot, I don't have the gizmo's for testing that, can I play with it? turn it in or out a turn, see if it makes a difference?

And the coding plug, can I just run without it, I don't need to reset motronic or anything?

Compression, it's not accurate, just a press in gauge, but it has plenty, It will lock up the rear wheel if you cut down to 2nd.

I have done all the tank internals, new fuel pump, filters, hoses.

The cam sprockets went back on fine, I don't see any issue there...

I don't have much time atm, but taking this on board for when I do get time.

Thanks again

 

 

Thanks for your insights, food for thought. CCP relay, good point.

Has C02 Pot, no O2 sensor.

Open exhaust, staintune, no cat

New, balanced (1200) Injectors. New coils, leads, HES.

Heads had valve grind very recently.

The dead spot usally is about 4000rp , throttling on to pass a car, yikes. It's almost imperceptable atm, that's what I've been basing the TPS scenario on... I do't think it's dependamt on any gear, just more noticeable in 5th.

I have the worn dogs on the gearbox, so it'll give tha little lurch in top, but unrelated, I'll get a new gearbox, if I don't outlive this.

Compressions are a bit off 80-90 vs 90-100.

I've had the airbox out, fitted cone filters, but gone back to airbox, TB's are clean as BBS also.

I won't comment further, Isle try it without the CCP relay and report back.

As you can tell, I'm just an amateur, and I don't want to take this into a shop, they'd go on a fishing expedition at $140 an hour.

Has new cam chain tensioners, both sides also, had the heads off it, but pretty sue the cam chains were tied back and went back on correctly.

Should've done the rings while I had the heads away, the bore is perfect, still crosshatched, and rings are sharp, so we left it.

Cables are new, quite possible they are holding open the RH throttle, I'm adjusting it at the crossover on the LHS as I've run out of adjustment on RHS.

I set the balance just off idle, about 2000RPM (as well as idle).

I have the original TB's, They seem okay, I could rebuild them, but they not loose at all, I could swap them back, see if that makes a difference, but the dead spot problem carried over from 1 set to the next.

Anyway, appreciated, enough for now, I'll take it for a run without the CCP relay.

Chers

 

[dirtrider]

Morning Fir Cologne

 

I had a little tinker, and checked the TPS settings, it was 255, I adjusted it down a few points, to 150,--  I'm not sure what you are doing with that TPS, what are those numbers? Are those numbers thousandths of a volt?  .255v (volts) &  .150v (volts) or do they have some other meaning?

 

With key-ON,  choke OFF, & L/H throttle cam on it's base idle screw you should be seeing a TPS voltage of between .365v & .385v between pins 1 & 4 at the TPS connector. (on the 1100 I usually set it to around .385v). 

 

The Bosch  0 280 122 201 seems to be the correct number on the TPS body (I didn't open your link as I am on a work computer) .

 

You can run it with the Co pot completely disconnected (we used to run them like that here in the U.S), it will idle a bit on the rich side but should run OK like that as it will be slightly richer just above idle. The Co pot has very little effect on fueling at anything over 1/4 throttle positions (it is/was only for idle Co. control for some European countries). 

 

 

 

[Fir Cologne]

14 hours ago, dirtrider said:

 I'm not sure what you are doing with that TPS, what are those numbers? Are those numbers thousandths of a volt?  .255v (volts) &  .150v (volts) or do they have some other meaning?

Yeah, sorry, my bad. It was .355v not 255.

The dead spot migrates up or down with TPS settings...

TPS is the only variable I have a new fuel pump, never checked regulator, but tuned right, this engine will rip your arms out, same cam timing, I had heads off, cable (zip tie) tied chains on sprockets.

I'm ordering a used TPS, see if that makes a difference?

When I get time I want to put the original cable back on it, don't like the aftermarket set up, it sticks... And go through whole procedure, zero etc from the start.

Following sport touring forum for some valuable insights.

[dirtrider]

9 hours ago, Fir Cologne said:

Yeah, sorry, my bad. It was .355v not 255.

The dead spot migrates up or down with TPS settings...

TPS is the only variable I have a new fuel pump, never checked regulator, but tuned right, this engine will rip your arms out, same cam timing, I had heads off, cable (zip tie) tied chains on sprockets.

I'm ordering a used TPS, see if that makes a difference?

When I get time I want to put the original cable back on it, don't like the aftermarket set up, it sticks... And go through whole procedure, zero etc from the start.

Following sport touring forum for some valuable insights.

Morning   Fir Cologne

 

Trying another (known good) TPS might not be a bad place to start. It should work & run OK at .355 volts if your meter is accurate & your meter connections are resistance free.   

[Fir Cologne]

I have a used TPS in the mail, hopefully that will eliminate that possibility.

Off topic, but can't find an answer; how much pressure should there be in LHS valve cover?

I've replaced the Oh rings on the filler cap as it was leaking, went for 600K ride, still leaking slightly. Yep, there's a million forums on that, but is it supposed to blow so hard out of the valve cover with the cap off? I'm told it's normal, but thought I'd 'phone a friend', before I took to it with any tools...

Is this why it has the 2 Oh rings?

Cheers

[dirtrider]

11 hours ago, Fir Cologne said:

Off topic, but can't find an answer; how much pressure should there be in LHS valve cover?

I've replaced the Oh rings on the filler cap as it was leaking, went for 600K ride, still leaking slightly. Yep, there's a million forums on that, but is it supposed to blow so hard out of the valve cover with the cap off? I'm told it's normal, but thought I'd 'phone a friend', before I took to it with any tools...

Is this why it has the 2 Oh rings?

Cheers

Morning   Fir Cologne

 

Pressure spikes inside the BMW 1100/1150 crankcase are normal, there is no published specification (that I know of) so I can't give you a pressure number but it is high enough to cause oil leaks if everything isn't sealed up properly. (just run the engine for a short time  with the oil fill cap removed to see how big the crankcase pressure swings are)

 

On the BMW 1100/1150 boxer engine both L/H & R/H  pistons move out & in together so that causes a pressure spike when they move in together decreasing crankcase volume. (this pressure increase/decrease occurs equally inside the crankcase  &  both side valve covers). 

 

The crankcase pressure is vented into the air box with the venting into the air box being timed through a timed-hole in the rotating crankshaft as well as that timed-vented air is passed through a long  oil-separation passage at the rear of engine. 

 

A lot of combustion blow-by leakage can raise internal crankcase pressures as well as over-filling the crankcase with oil decreases the crankcase air chamber volume so can slightly raise the pressure spikes. 

 

The one area that is critical on the BMW 1100/1150 boxer engines  is the rear crankshaft main bearing oil seals (there are 2). The seals need to be driven in to the correct depth as the timed crankcase venting actually vents between the inner & outer seals. If the outer seal is driven in too far it blocks the crankcase venting & that really increases internal pressure & oil leaks, or even worse, can blow the oil sight glass out. 

 

There is also a drain valve on the lower left rear on the air box to allow draining trapped vent oil as well as any water taken in thorough the intake snorkel. (this drain valve should be opened once in a while to drain the lower chamber of the air box).

 

As for your oil filler leaking, could be caused by damage to the "O" ring sealing areas, or improperly sized "O" rings, or too much crankcase pressure (see the above), or ????.

 

On leakers (personally) I put a little power-steering stop leak (basically seal-swelling-conditioner) on the new "O" rings at installation as that swells the "O" rings up slightly causing a tighter seal.   

 

 

 

 

 

 

[Fir Cologne]

On 2/26/2022 at 8:18 PM, dirtrider said:

Morning   Fir Cologne

 

Trying another (known good) TPS might not be a bad place to start. It should work & run OK at .355 volts if your meter is accurate & your meter connections are resistance free.   

Well well, I bought a new multi meter, my old one was falling apart. Also bought  a Seibel air horn, little compact unit, awesome, I'm gunner frighten old ladies a crossings.

But the really good news, my new, used TPS arrived, I checked the old one, was on 370, set up the new one to 360.

Didn't want to fire, had to se the choke, had to raise the idle, just by ear, no manometer.

But what a difference, it just sounds better, better throttle response, wants to tear my arms out.

So pretty sure it was TPS all along. Now I can set it all up properly, haven't checked with manometer, but now have adjustment on RHS BBS.

I'm confident I can swap out the aftermarket cable for the original, and set it all up from scratch.

Can still hear the sound of a brand new TPS being thrown in the rubbish bin, Vince might be good at rebuilding gearboxes...

Anyway, certain this is sorted, thanks for your input!

Stephen