CO sensor, what is it?

[rol1]

I have a wrecker auction 96 1100rt, without a key. So I bought a Speeduino. One of the inputs is the MAP sensor. Is this anything like the CO sensor? I see the vac lines from the underside of throttle body to the left side sensor. What is the CO sensor? How does it work? 
   
Is CO concentration of oxygen? Another way of saying MAP sensor?

[dirtrider]

17 hours ago, rol1 said:

I have a wrecker auction 96 1100rt, without a key. So I bought a Speeduino. One of the inputs is the MAP sensor. Is this anything like the CO sensor? I see the vac lines from the underside of throttle body to the left side sensor. What is the CO sensor? How does it work? 
   
Is CO concentration of oxygen? Another way of saying MAP sensor?

Afternoon  rol1

 

No, they are different sensors.

 

The MAP (Manifold Absolute Pressure) is a vacuum sensing sensor (BMW 1100rt doesn't use one). The BMW Co. sensor is basically NOT a sensor but is an idle Co. trim potentiometer (mechanically adjusted resistor) that is used on older BMW bikes to set the Co. levels going out the exhaust at idle (is ONLY used on motorcycles without an o2 sensor plus it needs to see NO CCP, or a non U.S. CCP ).

 

The vacuum lines going to the  L/H side on your 1100rt are going to the emission Evap. canister purge solenoid not a MAP sensor. 

 

You will have to call  Speeduino about using a MAP sensor on a BMW boxer twin as the 360° firing 2 cylinder boxer has very harsh & wildly pulsating vacuum pulses (not the best source to get a stable MAP output signal). 

 

Your BMW 1100rt boxer uses an  Alpha-N fueling control system so never used a MAP sensor. 

 

The 1100rt doesn't use an anti-theft key system so you can actually remove the ignition switch key barrel then use a screwdriver to turn the ignition on (or buy another ignition switch & key on E-Bay).   All the Motronic fueling computer needs to start & run is proper 12v power to the correct pins & all the engine sensors hooked up &  working. 

 

   

[rol1]

Then I can jump the plug in the harness and crank it up? The switch has 5 wires according to the electrical schematic, red, green, violet, gray and grey/blue?? 

[dirtrider]

12 hours ago, rol1 said:

Then I can jump the plug in the harness and crank it up? The switch has 5 wires according to the electrical schematic, red, green, violet, gray and grey/blue?? 

 

Morning  rol1

 

Yes, just jump red to green, then with kill switch ON, side stand UP, transmission in neutral it should then start & run. 

 

But the ignition switch has more outputs that power other items like the brake light, headlight, dash gauges, etc so keep that in mind. 

 

There is a small set screw on the ignition switch barrel assembly (usually under some red sealer). If you dig that sealer out then remove the small screw you can drop the actual bottom switch part down out of the upper barrel assembly then the removed switch can be operated with a proper fitting screwdriver or something.  (this powers all the required circuits when turned on)

 

[rol1]

Is the setscrew a flathead? Less room to get a direct shot around the forkleg. Looking for a shorter screwdriver. 

[rol1]

Back to the CO Potentiometer is not a sensor. The small rubber line from each TB that join together and runs to the left side by the fuse box is to the charcoal canister? Part of the emissions stuff?

[dirtrider]

34 minutes ago, rol1 said:

Is the setscrew a flathead? Less room to get a direct shot around the forkleg. Looking for a shorter screwdriver. 

 

Afternoon rol1

 

It is set screw, but with a flat blade screwdriver slot instead of an allen hex. 

[dirtrider]

40 minutes ago, rol1 said:

Back to the CO Potentiometer is not a sensor. The small rubber line from each TB that join together and runs to the left side by the fuse box is to the charcoal canister? Part of the emissions stuff?

Afternoon rol1 

 

The small rubber hoses run from each throttle body nipple to an electrical/vacuum solenoid  (BMW calls it a fuel tank breather valve)  on the L/H side. Then from the electrical/vacuum solenoid a hose runs back to the right rear of the motorcycle to the evap canister (charcoal canister). If your bike still has one as a lot of those were removed by previous owners.

 

This is mainly a USA emission thing as most other countries didn't have that charcoal canister set up.

 

[rol1]

Tried jumping the grn and red, but no fire. Don’t smell gas at the exhaust. 
 

Do non canister bikes have the nipple for potentiometer on the TB? Ir just for our market? 
 

Now to pull the plugs without the list of special tools. 

[dirtrider]

Morning  rol1

 

Tried jumping the green and red, but no fire. Don’t smell gas at the exhaust.-- Is the side stand UP??  Can you hear the fuel pump run for about 3 seconds when you jump the red to green?   

 

How long did that motorcycle sit before you bought it? If it sat for a long time then the fuel pump might be stuck or corroded up. 

 

Or the insides of the fuel tank could be all gunked up with old fuel or stale-fuel varnish.

 

If you don't hear the fuel pump run for 2-3 seconds at first red to green jump then you need to find out why. The pump should run for 2-3 seconds at red to green jump then it will quit until engine is cranking so should start running again at engine cranking.  

If the pump runs then you need to check for actual fuel flow at the fuel return hose coming from the rear  (if no fuel flow then you need to find out why.

If you DO have fuel flow coming  out of the return line coming from the rear then you need to make sure your fuel injectors are electrically triggering (a NOID light works best for this) 

 

LOTS of things could be wrong with a BMW boxer bike that has been sitting for a long time, so you need to work your way through them one at a time until you find the problem, or problems. 

 

 

Do non canister bikes have the nipple for potentiometer on the TB? Ir just for our market? -- All the 1100 Throttle Bodies have the vacuum nipples on them, on US (emission compliant) motorcycles those nipples have hoses going to the purge solenoid, on non US emission compliant 1100 bikes those nipples have rubber vacuum caps on them to plug them off. 
 

Now to pull the plugs without the list of special tools.-- You can just use a thin-walled 16mm (5/8")  standard spark plug socket or even use a standard 16mm (5/8") deep socket--  (must be thin walled socket to fit through the valve cover hole) , or worst case just remove the valve covers then the spark plugs are more easily accessible.

[rol1]

I don’t get a seconds long sound, just a slight click. It has been sitting too long. 

I had checked the sidestand and that it’s in neutral, but didn’t find a kill switch. Almost all the faring is gone and the faring holder was toast. Where is a kill switch mounted? Or is it part of the ignition switch?

 

Does the tank breather valve allow flow from the canister to the TB at higher RPM? Or does it somehow know how much to lean out the mix by fuel table, temps, and RPMs?

 

thanks for the info, not exactly covered in the manual. 

[dirtrider]

Morning  rol1

 

I don’t get a seconds long sound, just a slight click. It has been sitting too long.--- That probably means the pump is either corroded or stuck (if it sat for a long time with old stale fuel in the tank then the insides of the tank can be a real mess). If the inside of the tank is a mess then your fuel injectors might also be stuck or plugged.  

I had checked the sidestand and that it’s in neutral, but didn’t find a kill switch. Almost all the faring is gone and the faring holder was toast. Where is a kill switch mounted? Or is it part of the ignition switch?--- Kill switch is on the R/H handlebar switch pod. 

 

Does the tank breather valve allow flow from the canister to the TB at higher RPM?--- Yes, but also under some lower RPM conditions. It just doesn't purge at idle. 

 

Or does it somehow know how much to lean out the mix by fuel table, temps, and RPMs?-- All those things plus the o2 sensor & throttle opening angle, if the o2 sensor is working then that is the main fueling control when in closed loop. 

 

 

 

 

[rol1]

On 5/12/2022 at 10:14 AM, dirtrider said:

on older BMW bikes to set the Co. levels going out the exhaust at idle (is ONLY used on motorcycles without an o2 sensor plus it needs to see NO CCP, or a non U.S. CCP ).

When I read this as saying I had no o2 sensor I got confused. I do have a narrow band o2 sensor? Just not operating in openloop?

 

 I don’t see a kill switch. 

[dirtrider]

Evening rol1

 

The US bikes had an o2 sensor (no Co pot) as they had a cat, most non US bikes had a Co pot & no cat.

 

On BMW 1100 boxer bikes if the correct CCP isn't installed in the fuse box  the o2 sensor will do nothing so they will run in open loop.

With a non-cat CCP (or no CCP)  the Motronic 2.2 looks for a Co pot & disregards the o2 sensor input.   

 

Your kill switch paddle looks to be broken off.

 

[rol1]

Would the motor turn over if the kill is engaged, turned off? 

[dirtrider]

11 hours ago, rol1 said:

Would the motor turn over if the kill is engaged, turned off? 

Morning rol1

 

Would the motor turn over

 

If the kill is engaged (on)?    Yes

 

If turned off?    No

[rol1]

On 5/21/2022 at 3:47 PM, dirtrider said:

Evening rol1

 

The US bikes had an o2 sensor (no Co pot) as they had a cat, most non US bikes had a Co pot & no cat.

 

 

On 5/21/2022 at 3:47 PM, dirtrider said:

Since I have the CO pot that means I have no O2 sensor or cat? 
 

Found a led and the injectors got signal. Which tank wires do I check for pump power and switched ground? I should be taking notes. I’ve read your responses in other threads and know you’ve answered before. 

[dirtrider]

Quote

 

Since I have the CO pot that means I have no O2 sensor or cat? 
 

Found a led and the injectors got signal. Which tank wires do I check for pump power and switched ground? I should be taking notes. I’ve read your responses in other threads and know you’ve answered before. 

 

Morning rol1

 

Between the green/with white stripe & the brown wire. 

 

Brown is low (ground) & the green/with white stripe is 12v+ to the pump, comes on for about 3 seconds at key-on, then doesn't come back on again until engine is cranking.  The 12v comes from the fuel pump relay. 

 

If you have power & ground at  the pump pass-through connector don't automatically assume that 12v B+ & ground is reaching the pump inside as I have seen the solder connections right at the pump pass-through plate have opens or high resistance. 

 

 

[rol1]

Fuel pump lights up. Looking under the tank I have no disconnects. 4 lines connected to barbs off the plate. Hose doesn’t crack under twist. Looks like the disconnects are around $100. Think I’ll get some of those special hose clamps. What are the 2 small lines? The tank vent? Lines to the carbon canister? Do I need them? 

 

[dirtrider]

23 minutes ago, rol1 said:

Fuel pump lights up. Looking under the tank I have no disconnects. 4 lines connected to barbs off the plate. Hose doesn’t crack under twist. Looks like the disconnects are around $100. Think I’ll get some of those special hose clamps. What are the 2 small lines? The tank vent? Lines to the carbon canister? Do I need them? 

 

Afternoon rol1

 

2 smaller lines are: fuel  tank vent line (is for the fuel tank vent plus on US bikes that vent hose went to the carbon canister (evap canister).

 

The other line is the fuel filler cap ring water drain, it goes through the tank then exits behind the riders foot peg.  

 

You absolutely need the tank vent line, you can live without the filler cap drain line but it should stay operational if possible. 

 

There are matching drain & vent hoses inside the fuel tank & those are special & expensive fuel submersible rated. (they both attach to the inside of the fuel pump plate)

[rol1]

28 minutes ago, dirtrider said:

 

 

There are matching drain & vent hoses inside the fuel tank & those are special & expensive fuel submersible rated. (they both attach to the inside of the fuel pump plate)

When I read the threads about replacing intank lines for the fuel pump I don’t see any reference to those little ones. I will find out what I need when I pull it apart, but what can I expect?

[Brodiepunker18]

https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=51680&rnd=09082020
 

 

the two vent lines are number 2 from the filler cap to the bottom plate.

 

you might want to look around at price but I’ve found the Max BMW online is usually a bit cheaper than other bmw DEALER sites for parts. 
 

On the link I’ve attached you can look at any parts fiche for any parts you’re looking for and get the part number to shop around or just order from there.

[rol1]

Will I be able to remove the pump/filter/float without cutting or removing the vent lines? If I don’t have to buy expensive lines. Maybe I’ll get lucky and find a good set of hoses. 

[Brodiepunker18]

I just did my fuel filter on my rt and was able to get it done without removing and replacing those lines. 
 

just be careful…I would definitely look at them and see how they look when you’re inside there.

[dirtrider]

10 hours ago, rol1 said:

Will I be able to remove the pump/filter/float without cutting or removing the vent lines? If I don’t have to buy expensive lines. Maybe I’ll get lucky and find a good set of hoses. 

Morning   rol1

 

You will probably be able to pull the pump  pass-through plate off just far enough to get to the rear of it but with you not knowing what is wrong inside then you are probably going to want to remove it completely so you can thoroughly inspect it, test it, & look for what is wrong with it. 

[rol1]

Will I have enough slack to clear the float? Not that much, I’m thinking. But if I can remove the screen without klutzing it up I could blow out the pump, drop it back in. And maybe blow out the lines. But I’ll be able to judge state of lines and fuel pump. 
Speaking of fuel pumps, what does the Mini Cooper use? The pump for the 850 may be the same? Could close enough with a filter screen from the donor pump be worked??? $50 sounds better than $150, but not messing it up in the first place?? Invaluable. 

[dirtrider]

1 hour ago, rol1 said:

Will I have enough slack to clear the float? Not that much, I’m thinking. But if I can remove the screen without klutzing it up I could blow out the pump, drop it back in. And maybe blow out the lines. But I’ll be able to judge state of lines and fuel pump. 
Speaking of fuel pumps, what does the Mini Cooper use? The pump for the 850 may be the same? Could close enough with a filter screen from the donor pump be worked??? $50 sounds better than $150, but not messing it up in the first place?? Invaluable. 

Afternoon Rol1

 

It might, it depends on if the hoses were shortened or replaced. Sometimes those hoses get cut off just above the pass-through fittings to allow the pump pass-though plate to be removed.

 

Then once the plate is removed the clamps & hose stubs are removed, then it gets re-assembled  with new clamps & slightly shortened hoses.

 

That float (if your unit has one) sticks out at  funny angle so you will just have to deal with that at plate removal.  (caution: do not bend float arm)

[rol1]

Looks like I’ll be doing the whole thing. If the lines weren’t so brittle I could have accessed the unit. But ... 

 

Holding it and looking at it it looks kinda uniform while looking up ebay BMW fuel pumps. Looks like they are the same shape. The pumps  on Ebay were rated from 200 cfm to 340 cfm. The manual has stock as 110cfm. What negatives are there running ~200cfm?

 

The long white tube has deteriorated insulation and protective tubing to be replaced. Should be straight forward. The rest of the wires look and meter solid. 
 

I appreciate not going into this blindly. Thanks for the advice. 

[dirtrider]

4 hours ago, rol1 said:

Looks like I’ll be doing the whole thing. If the lines weren’t so brittle I could have accessed the unit. But ... 

 

Holding it and looking at it it looks kinda uniform while looking up ebay BMW fuel pumps. Looks like they are the same shape. The pumps  on Ebay were rated from 200 cfm to 340 cfm. The manual has stock as 110cfm. What negatives are there running ~200cfm?

 

The long white tube has deteriorated insulation and protective tubing to be replaced. Should be straight forward. The rest of the wires look and meter solid. 
 

I appreciate not going into this blindly. Thanks for the advice. 

Afternoon Rol1

 

I don't know what CFM means in relation to a fuel pump  (usually means Cubic Foot Minute), not typically how you would rate the flow of a fuel pump.

 

Are you sure that isn't L/H   (Liters Hour) the BMW 1100 fuel pump is typically rated at 110 L/H. 

 

 

[rol1]

Yes, you are right. Liter per hour. Would the regulator keep it at 3 bar even if it does 300 lph? Just more coming thru the return? Or would that increase the psi with the extra back pressure? I probably have o good selection of beemer cars. I can maybe find a new one. 

[dirtrider]

2 minutes ago, rol1 said:

Yes, you are right. Liter per hour. Would the regulator keep it at 3 bar even if it does 300 lph? Just more coming thru the return? Or would that increase the psi with the extra back pressure? I probably have o good selection of beemer cars. I can maybe find a new one. 

Afternoon Rol1

 

No way to tell for sure, (IF) the return side can flow ALL the return fuel without resistance or restriction then it should hold the specified 3  bar on the pressure side. 

 

Now if the return side can not flow that much return without resistance or restriction then the pressure side could go over 3 bar.   

 

Is your fuel pump wiring sized large enough (correct gauge)  to handle the current requirement of a 300 lph pump?

[rol1]

Guess I’ll compare wire gage while pulling pumps. Might even be able to find a couple of lengths of fuel proof wire for the float. Does the polarity of the fuel gage wires matter? They were broken near the plug on the backing plate. No insulation colors at the lower end.

 

I still have the Speeduino. But I’ll know that the ABS and Motronic module are working. 
 

 

[rol1]

Since I have the CO solenoid does that mean I don’t have the O2 sensor? Do I have a catalytic converter? I have seen the thread where the converter is gutted through a hole small enough to weld in a threaded bung for a O2 sensor. Or maybe an exhaust temperature sensor. Is that a cat on the no O2 sensor version? Do I have a non-US version?

[dirtrider]

13 hours ago, rol1 said:

Guess I’ll compare wire gage while pulling pumps. Might even be able to find a couple of lengths of fuel proof wire for the float. Does the polarity of the fuel gage wires matter? They were broken near the plug on the backing plate. No insulation colors at the lower end.

 

I still have the Speeduino. But I’ll know that the ABS and Motronic module are working. 
 

 

Morning Rol1

 

Wire gauge is important all the way through the pump circuit not just inside the tank.

 

The fuel gauge is just a wire wound resistor with moving contact but it could be polarity sensitive. 

[dirtrider]

12 hours ago, rol1 said:

Since I have the CO solenoid does that mean I don’t have the O2 sensor? Do I have a catalytic converter? I have seen the thread where the converter is gutted through a hole small enough to weld in a threaded bung for a O2 sensor. Or maybe an exhaust temperature sensor. Is that a cat on the no O2 sensor version? Do I have a non-US version?

 

Morning Rol1

 

There is no such thing as a Co solenoid on the 1100RT, are you referring to a CO Potentiometer (BMW calls it an Idle Regulating Valve) that has an adjustment screw on it, or to an Evap system vacuum solenoid ( BMW calls it a Fuel Tank Breather Valve) that has vacuum nipples on it? 

 

BUT___ I have seen a few BMW 1100 motorcycles with a cat & o2 sensor that did have a CO Potentiometer (Idle Regulating Valve)  but it was  added by the motorcycle owner at one time as they removed the CCP from the fuse box (that drove open loop operation) they then used the CO Potentiometer (Idle Regulating Valve) to trim the idle fueling richness.  (the BMW 1100 motorcycles with o2 sensor & cat did not come from  the factory with a CO Potentiometer but it could be added later if/when the CCP was removed)  

 

The (non o2 version) doesn't have a catalytic converter as the o2 sensor is needed for proper cat operation. The non-cat system looks similar to a cat equipped system except no o2 sensor & no internal catalytic bed.  

 

When asking questions about emission control, o2 sensor, or evap system things you should include the county that the motorcycle is in, and where it was originally sold (if known).

 

On U.S.A. BMW motorcycles we (members of the forum)  pretty well know all the original emission equipment the motorcycles were sold with but on non-USA motorcycles we usually have to look it up, or at least know what emission  control systems were required in the county that it was sold in at time of sale.  

 

 

 

 

[rol1]

This bike was unsold after a few months. Remains of the faring holder and windshield mechanism tweaked and locking the forks, $100. Plus title. Figured the frame was toast, but after pulling off a bunch of brokeness the frame don’t look so bad. It’ll never look good again. I’ll be Like a gorilla riding a warthog. When I get it running I might still set up the Speeduino for wideband O2. 

So if I have no O2 bung then I have no cat bed. Just some baffles where the cat bed would be? 
 

All it came with was a state issued title and it got towed from behind the Blvd Mall here in Las Vegas. I would have to refer to vin numbers for maybe more information. 

[dirtrider]

21 minutes ago, rol1 said:

This bike was unsold after a few months. Remains of the faring holder and windshield mechanism tweaked and locking the forks, $100. Plus title. Figured the frame was toast, but after pulling off a bunch of brokeness the frame don’t look so bad. It’ll never look good again. I’ll be Like a gorilla riding a warthog. When I get it running I might still set up the Speeduino for wideband O2. 

So if I have no O2 bung then I have no cat bed. Just some baffles where the cat bed would be? 
 

All it came with was a state issued title and it got towed from behind the Blvd Mall here in Las Vegas. I would have to refer to vin numbers for maybe more information. 

Afternoon  rol1

 

So a pretty good chance it was a USA motorcycle?

 

If it isn't a gray market import then it more than likely came with a cat & o2 sensor.

 

Doe s it still have the factory exhaust system? 

[rol1]

Yes, but haven’t got down in the dirt yet. 
OK, it does have the O2 sensor. And a CO potentiometer. With no CCP plug. Running in open loop with a cat. Well, first things first, get it to startup. 
 

Just going outside overheated my phone