runs rough when warm

The Motronic uses the O2 from idle to half throttle and theN uses an adaptation process to apply the extra fuel from an AF-XIED all the way from half throttle to WOT.

However, you shouldn't add an AF-XIED until you have your bike fixed.

Okay so then without the AFxied does the bike use the o2 to measure air/fuel from idle to WOT? and maybe my o2 is bad? but if it was bad shouldnt I have a trouble light?

Okay so then without the AFxied does the bike use the o2 to measure air/fuel from idle to WOT? and maybe my o2 is bad? but if it was bad shouldnt I have a trouble light?

Afternoon Matth3w

Yes, once warm the o2 sensor continually monitors exhaust gas oxygen content from idle to WOT. It doesn't monitor air/fuel, it only monitors the amount of oxygen remaining in the exhaust then sends that info in the form of a voltage output back to the Motronic. From the o2 sensor voltage input the Motronic then computes the amount of fuel to send via the injectors (only in closed loop operation).

While the o2 sensor feedback is received by the Motronic at all throttle openings & engine loads it is only used to compute fueling at steady throttle & light to moderate engine loads. The o2 input signal is not used at WOT or used at heavy acceleration, or used on deceleration.

I asked you earlier if your bike had the CCP in place & you posted back that "so I removed the yellow relay and it ran worse" . On the BMW 1100 motorcycle once you remove the CCP the Motronic no longer looks at, or uses, the o2 sensor to determine fueling as removing the CCP forces open loop operation.

Yes it still has it, its yellow and runs slightly worse at idle without it.

Yes it still has it, its yellow and runs slightly worse at idle without it.

Evening Matth3w

With it removed the fueling control ignores the o2 sensor input. You might re-try running with the CCP removed just as a re-verification test.

Yeah its not allot worse but its still worse with it removed. The best it runs is with the TPS pot turned as far counter clockwise as it goes which gives me 4.7~ volts at WOT on 3 and 4 but over 2 volts on 1 and 4 AND stuffing a rag in the center of the air cleaner. With all this done it almost runs 100% other than my top end isn't the same.

Lets go back to the TPS. if I'm supposed to get 5 volts on 3 and 4 at WOT with 1 and 4 set at or around .35 at idle and I've only achieved 3.9 volts on 3 and 4 on two different TPSs then what else can be causing this?

can one of the HES be bad enough to mess up fuel mixture at WOT but still let the bike run?

Something I just thought about at 1 in the morning is the fuel pressure regulator is a diaphragm correct? I've already checked the return pressure and I have a steady stream can that stream be too steady? Meaning more fuel is flowing back and not allowing a high enough pressure to the injectors so at a steady idle or low RPM it's fine but opened up there's not enough pressure and fuel?

Yeah its not allot worse but its still worse with it removed. The best it runs is with the TPS pot turned as far counter clockwise as it goes which gives me 4.7~ volts at WOT on 3 and 4 but over 2 volts on 1 and 4 AND stuffing a rag in the center of the air cleaner. With all this done it almost runs 100% other than my top end isn't the same.

 

Lets go back to the TPS. if I'm supposed to get 5 volts on 3 and 4 at WOT with 1 and 4 set at or around .35 at idle and I've only achieved 3.9 volts on 3 and 4 on two different TPSs then what else can be causing this?

Morning Matth3w

The TPS is capable of providing 5v on 3 to 4 (IF) the TPS is allowed to move full travel. If it isn't moving full travel then it won't provide a full 5v.

can one of the HES (outputs) be bad enough to mess up fuel mixture at WOT but still let the bike run?

Morning Matth3w

Possible but unlikely (at least I haven't ever seen that happen). But your problem seems to be an outlier so I wouldn't rule it completely out.

Something I just thought about at 1 in the morning is the fuel pressure regulator is a diaphragm correct? I've already checked the return pressure and I have a steady stream can that stream be too steady? Meaning more fuel is flowing back and not allowing a high enough pressure to the injectors so at a steady idle or low RPM it's fine but opened up there's not enough pressure and fuel?

Morning Matth3w

Definitely possible-- might be time to do a full fuel pressure test, both deadheaded & testing pressure with fuel pressure regulator included. Regulated fuel pressure spec is 43.5 psi.

Make sure the fuel pump has at least 12v going to it during the test.

Something I just thought about at 1 in the morning is the fuel pressure regulator is a diaphragm correct? I've already checked the return pressure and I have a steady stream can that stream be too steady? Meaning more fuel is flowing back and not allowing a high enough pressure to the injectors so at a steady idle or low RPM it's fine but opened up there's not enough pressure and fuel?

Have you measured the return flow to make sure you are getting 2 liters per minute returned at idle? The return flow can be low but still appear strong if you have leaks that haven't ruptured.

You can even get full pressure with leaks in the tank.

But if you have leaks it could certainly cause wot problems.

Something I just thought about at 1 in the morning is the fuel pressure regulator is a diaphragm correct? I've already checked the return pressure and I have a steady stream can that stream be too steady? Meaning more fuel is flowing back and not allowing a high enough pressure to the injectors so at a steady idle or low RPM it's fine but opened up there's not enough pressure and fuel?

 

Have you measured the return flow to make sure you are getting 2 liters per minute returned at idle? The return flow can be low but still appear strong if you have leaks that haven't ruptured.

 

You can even get full pressure with leaks in the tank.

 

But if you have leaks it could certainly cause wot problems.

Morning Roger

The 1100RT pump output spec is slightly less than 2 liters per minute (about 1.8 liters per minute). The 1150RT is 2 liters per minute.

Thanks I didn't know that. My question though is has it been measured? Just the right amount of leaking would allow correct pressure at idle and present a strong stream but be low enough to affect high engine loads.

Thanks I didn't know that. My question though is has it been measured? Just the right amount of leaking would allow correct pressure at idle and present a strong stream but be low enough to affect high engine loads.

Morning Roger

Yes, he should definitely measured it but he also needs to know that the flow he is measuring is at the specified pressure.

If the pressure regulator is defective he could measure the required 1.8 L/M flow but it might be at only 12 psi (that won't run it properly at WOT)

He needs to have both the flow & the pressure to run properly at WOT.

Morning Roger

Have you ever seen or measured one with the fuel lines hooked up in reverse?

I can't say that I have tried to ride a BMW 1100/1150 with the lines hooked up in reverse. (obviously the pressure regulator wouldn't be working correctly)

I guess all this fuel flow/pressure talk got me thinking.

Matth3w-- have you verified that the lines from tank to regulator are hooked up correctly? (just a quick thought)

They have never been both removed at the same time so it would be impossible to be hooked up in reverse. I can easily check the 1.8 liters per minute when I get off work, ill have to order a pressure gauge from Amazon or something.

I checked the codes last night and just got 4444 also read they are pointless lol.

This leaking youre talking about do you mean inside the tank because I have no external leaks, also the pump is only 2 years old.

They have never been both removed at the same time so it would be impossible to be hooked up in reverse. I can easily check the 1.8 liters per minute when I get off work, ill have to order a pressure gauge from Amazon or something.

 

I checked the codes last night and just got 4444 also read they are pointless lol.

 

This leaking youre talking about do you mean inside the tank because I have no external leaks, also the pump is only 2 years old.

 

Morning Matth3w

There is a "U" shaped hose inside the fuel tank that can have develop split in it. The split allows some of the required pump pressure & fuel flow to just return to the inside of the tank. An internal hose clamp can also come loose allowing fuel leakage at the clamped fittings.

As a rule a fuel flow test at the return line will show this (internal hose leak or clamp leakage) as a reduced or non existent fuel return flow. (but this assumes the pressure regulator is operating correctly) -- I have seen a few pressure regulators leak but never malfunction enough to cause poor running at high RPM's (but it sure is possible even though I haven't seen it).

You might be at the point of going after non normal failure things.

Morning Matth3w

I just went back & re-read this thread from the beginning just to see if we are staying on track-- This thread has gone on for a long time & become somewhat convoluted.

So let's address a few things that we might have missed--

__When was the last time that the bike ran good at WOT? (we need to know this)

__What has been done to the bike since it last ran good at WOT? (just done BEFORE you noted the poor WOT performance not done after that time in troubleshooting things)

__When you tested the TPS pins 3 to 4 for voltage output were you using the handlebar twist grip or actually turning the Throttle Body cam by hand?

__Why was a new fuel pump installed 2 years ago?

__Why was a new ignition coil installed?

__Any more bike history or things done that you can remember prior to noticing the WOT problem ?

It was my uncles bike, it started to stumble just before winter almost 4 years ago, he took it to a dealer they told him it needed a complete engine rebuild due to a burnt exhaust valve and they wanted $3k+ so he went and just got another bike, he sold me the bike for scrap value because I didn't believe that was the case, it had good compression on both sides which says no burnt valve. I replaced fuel pump and it fired and ran good all of summer last year. Since I had it running good and it has almost 100k miles I decided to replace some things over the winter, repacked aftermarket muffler, replaced coil, oil, plugs, wires. Rear tire, drained tank and let it sit dry over winter and filled with 93 first nice day, cleaned TBs and injectors, synced TBs which it wasn't far off and set TPS to .37. And a new battery. Most everything I've done I replaced with old part to confirm I didn't get a bad new part,

When setting tps I rotate just the left side butterfly. With tps off and using my finger to rotate that little dingy it reaches 4.9 on 3 and 4 but won't go that high while attached.

It ran great last summer on 2 year old fuel and oil ...

In case you've,missed im 100% sure its a lean problem because it runs better with the air choked off.

Also it has a k&n air filter in it which I cleaned without the k&n kit.

It was my uncles bike, it started to stumble just before winter almost 4 years ago, he took it to a dealer they told him it needed a complete engine rebuild due to a burnt exhaust valve and they wanted $3k+ so he went and just got another bike, he sold me the bike for scrap value because I didn't believe that was the case, it had good compression on both sides which says no burnt valve. I replaced fuel pump and it fired and ran good all of summer last year. Since I had it running good and it has almost 100k miles I decided to replace some things over the winter, repacked aftermarket muffler, replaced coil, oil, plugs, wires. Rear tire, drained tank and let it sit dry over winter and filled with 93 first nice day, cleaned TBs and injectors, synced TBs which it wasn't far off and set TPS to .37. And a new battery. Most everything I've done I replaced with old part to confirm I didn't get a bad new part,

 

When setting tps I rotate just the left side butterfly. With tps off and using my finger to rotate that little dingy it reaches 4.9 on 3 and 4 but won't go that high while attached.

 

It ran great last summer on 2 year old fuel and oil ...

 

In case you've,missed im 100% sure its a lean problem because it runs better with the air choked off.

 

Also it has a k&n air filter in it which I cleaned without the k&n kit.

Afternoon Matth3w

The dry tank all winter sort of puts up a bit of a red flag as that allows the internal hoses to dry out (did you install a new U shaped hose inside the tank when you replaced the pump). Also did you use proper fuel injection rated hose clamps inside the tank & not standard worm-drive type clamps?

How did you clean the injectors? If you sent them out to an injector shop then good chance they are OK as far as performance goes. If you cleaned them at home then possibly they are gummed up inside from washed in gunk.

I do agree it sounds like you have a lean issue but the big question is WHY. Also keep in mind that lack of spark at WOT can cause about the same, runability appearing problems, as a richer mixture ignites easier even with a poor spark.

I guess at some point you are going to have prove out the fuel flow delivery (1.8 liters/minute) at proper 43+ PSI delivery pressure.

If the fuel pressure/flow rate tests out OK then maybe do an injector spray test with fuel pump running.

One thing to sort of keep in mind is that it ran good BEFORE all the winter work was done so a good chance that your problem is related to that.

Did not replace that U hose.injectors were cleaned by direction of a YouTube video, put a mixture of seafoam and gas in a bowl, let gravity feed the injector and manually toggle power the the injector to open and close. Is there a way to test ohms on the coil at a high rpm?

Ok I tried it 3 different times, warmed the bike up, removed fuel return line. Start bike and timer same time and i got almost 3 liters in a minute each time. Bike was idling without rev lever at 1100 entire time.

Ok I tried it 3 different times, warmed the bike up, removed fuel return line. Start bike and timer same time and i got almost 3 liters in a minute each time. Bike was idling without rev lever at 1100 entire time.

Evening Matth3w

That's way more then enough fuel delivery (volume wise), that usually says fuel pump & internal hoses are not the problem.

What that doesn't tell us is if that fuel has enough pressure behind it to inject properly. (more then likely it has the pressure as it has to get by the pressure regulator to

flow out the return line). BUT, this assumes that the pressure regulator is operating properly.

I guess with your problem being difficult to pin point so far (personally) I would want to verify the fuel operating pressure just to take that off of the possibility list.

I'm also thinking that at some point you are probably going to have to do an injector spray test & spray quantity comparison test.

What do I need to do for the pressure test?

I recorded the sound of my ride again, unfortunitly I used a site that only hold the audio for 24 hours but it was quicker than utube. so what I did was warm the bike up then one side at a time remove the injector while running and let it spray into a bucket for about 30 seconds . after so it sound like it was running better other than the pops in the exhaust, so I took it out WOT all the way to 5th and it ran much better than the last run (if you compare the 2 audio clips) it still had a small amount of hesitation which sounds like backfire in the exhaust but was running much better, this is with tps set to .36 on 1 and 4 and nothing else messed with the only other difference is now my tank is only about 1/4 full when my last run had about 3/4. ive drained allot doing this fuel tests and idles. can you think of any reason other than running the bike with one injector off at a time why its running better but stil not great? I finally got a hold of a mobile BMW mechanic and I kid you not he told me to scrap it and move on, "if it takes longer than 3 days to figure out the problem its time to get a new bike"

audio clip https://clyp.it/wbgx4j23

Ok I tried it 3 different times, warmed the bike up, removed fuel return line. Start bike and timer same time and i got almost 3 liters in a minute each time. Bike was idling without rev lever at 1100 entire time.

I agree with DR. That's a lot higher than usual. It suggests that either you have a very strong pump or that your fuel pressure is low, making it easier for the pump.

I recorded the sound of my ride again, unfortunitly I used a site that only hold the audio for 24 hours but it was quicker than utube. so what I did was warm the bike up then one side at a time remove the injector while running and let it spray into a bucket for about 30 seconds . after so it sound like it was running better other than the pops in the exhaust, so I took it out WOT all the way to 5th and it ran much better than the last run (if you compare the 2 audio clips) it still had a small amount of hesitation which sounds like backfire in the exhaust but was running much better, this is with tps set to .36 on 1 and 4 and nothing else messed with the only other difference is now my tank is only about 1/4 full when my last run had about 3/4. ive drained allot doing this fuel tests and idles. can you think of any reason other than running the bike with one injector off at a time why its running better but stil not great? I finally got a hold of a mobile BMW mechanic and I kid you not he told me to scrap it and move on, "if it takes longer than 3 days to figure out the problem its time to get a new bike"

 

 

I recorded the sound of my ride again, unfortunitly I used a site that only hold the audio for 24 hours but it was quicker than utube. so what I did was warm the bike up then one side at a time remove the injector while running and let it spray into a bucket for about 30 seconds . after so it sound like it was running better other than the pops in the exhaust, so I took it out WOT all the way to 5th and it ran much better than the last run (if you compare the 2 audio clips) it still had a small amount of hesitation which sounds like backfire in the exhaust but was running much better, this is with tps set to .36 on 1 and 4 and nothing else messed with the only other difference is now my tank is only about 1/4 full when my last run had about 3/4. ive drained allot doing this fuel tests and idles. can you think of any reason other than running the bike with one injector off at a time why its running better but stil not great? I finally got a hold of a mobile BMW mechanic and I kid you not he told me to scrap it and move on, "if it takes longer than 3 days to figure out the problem its time to get a new bike"

 

 

Morning Matth3w

 

That thing still sounds weak in the mid range (not crisp like it should).

 

How did you clean the injectors?

 

You need to look at the spray pattern on a piece of cardboard to verify that they spray a nice looking pattern without sputters.

 

You also need to point each injector into similar containers (like matching quart jars), then manually trigger the injectors (ground the injector low side) for a given time, then verify that BOTH SIDES are squirting the exact same amount of fuel into the jars.

 

You still might have fouled fuel injectors from the cleaning procedure (something that should be eliminated anyhow).

 

 

 

I agree with DR the fuel injectors still need to be eliminated from the problem.

I had a bad injector on my rig. These were new injectors installed and only had 6k on them. Not quite sure what the problem was with them (sent back to vendor and am awaiting an answer from them) but at times it sounded as though it would run on only one cylinder. It missed when running above idle and could not get to rev limiter at all, very sluggish on full throttle opening at any RPM above idle and was doing the herky jerk when giving it throttle. At idle whacking the throttle to full open, it would die. Had old injectors and installed them and all problems went away. This may not be your problem, but it might be worth it to find some other injectors and give those a try and see if it makes any difference. You may have cleaned them but if something is wrong with the solenoid that controls the pulse you would not be able to see that unless you hook up some sort of test light to monitor it during a ride.

What's happening?