Power loss at 1.5k RPM general ignition issues

[blockade]

Hi Folks,

I have been scouring the internet, this board and every other I could find, to get some information or ideas on what could be happening with my bike - a 2004 r1150r 2-spark with about 20k miles.

My issues started with a bad battery. According to the local parts shop that tested it it had a bad cell. I grab a new one from beemerboneyard and the bike ran fine for about a week after swapping it out. The issues started with a surging (at 1500 RPM) and trouble starting it up, which I seem to have cured with an injector soak. I was due for a valve job so I started with that. I'll list out all of my diagnostic steps to date, I will admit that I am pretty new to the oil head so don't feel like you're insulting me if you suggest something obvious that I could have missed or could have screwed up when performing a piece of maintenance.

Another symptom I have observed - holding the throttle at 2k rpm I can watch the tach fluctuate anywhere between 1.8k and 2.2k. It's not a violent fluctuation but it is noticeable when I would expect it to just hold steady.

In order:

• New Battery
• Reset TPS by turning ignition on and opening/closing throttle three times.
• Valve adjustment (first time doing this myself, however I found it to be very straight forward)
• Ran bottle of Techron through the tank
• Checked all lines/connections from tank to fuel system
• spark plug check (visual)
• spark plug cleaning (using hot lemon juice and a brass wire brush)
• Throttle body balance (used a homemade manometer that I have used successfully on other vehicles)
• spark plug replacement
• Stick Coil/Coil test (used a "spark plug tester" from harbor freight)
• Ran second bottle of Techron through the tank
• Reset TPS by removing fuse #5 and opening/closing throttle 3 times with ignition on.
• O2 sensor disconnect (unplugged and ran the bike without the sensor)
• Cat removal/reinstall
• Injector cleaning (soaked in Techron overnight)
• Check for Vacuum leak by spraying WD-40 on all vacuum lines/air intake joints
• Used DVM to check TPS voltage
• Disconnected top fuel line disconnect (above right throttle body) to check return fuel flow - no fuel flow in line
• Disassembled Fuel Tank, found split in in-tank fuel line between fuel filter and external lines.

I will readily admit to very little expertise when it comes to electrical systems - shocked the hell out of my self testing the lower plugs - however I do have a volt meter if you can provide me any guidance on what I should check, values, etc. I realize that my test against the Stick Coils is not the most effective but have no idea how else to test. I also suspect the HES, but my symptoms don't seem to point to the common HES issues (namely random stalling and hard start/no start).

I've got an appointment with the local BMW Stealer next week - would love to be able to resolve this before then, preferably before this weekend.

 

[blockade]

And because everyone likes pictures:

 

[DANIELF]

Did you remember to reset the throttle after the new battery install?

 

[blockade]

Yes - I'll add that to the list. I actually did that multiple times, after the battery was reinstalled and then again later by removing fuse #5.

 

[lkchris]

1500 is just off idle. I'd suspect a vacuum leak.

 

[blockade]

Ok, good idea. I'll get out my bottle of soapy water and see if i can chase something down... Any pointers or common places of failure I should start?

I did do a canister removal a month ago which involved the vac system, but I followed instructions and sealed off the tube that led to the canister with one of the bolts...

 

[henzilla]

Welcome to the forum.

just looking at that side shot, is the rubber plug on the bottom of injectors? Part of the cannister plumbing removed.
And yes, valve adustments are pretty sraightforward, but sometimes can be too tight the first few times folks tackle it.

 

[blockade]

Welcome to the forum.

just looking at that side shot, is the rubber plug on the bottom of injectors? Part of the cannister plumbing removed.
And yes, valve adustments are pretty sraightforward, but sometimes can be too tight the first few times folks tackle it.

Thanks for the welcome.

I'm not certain I understand what you're referring to. Are you talking about the bottom of the injector or throttle body? And what do you mean by "part of the canister plumbing removed"?

 

[henzilla]

Mis-speak on my part... The bottom of each throttle body has a brass nipple and is part of vapor recovery/ cannister plumbing. If a complete canisterectomy was done, those hoses going to bottom of t-bodies are typically removed and rubber plugs installed in their place.
You did a sync hooking up to those ports, so maybe it just looks missing.

 

[happy wanderer]

Ok, good idea. I'll get out my bottle of soapy water and see if i can chase something down... Any pointers or common places of failure I should start?

I did do a canister removal a month ago which involved the vac system, but I followed instructions and sealed off the tube that led to the canister with one of the bolts...

Soapy water? Not a pressure leak but a vacuum leak. You'll need to use WD40 or propane or something combustible. Run the bike and spray WD around the intake tubes forward of the throttle bodies and around the shafts of the throttle bodies. Also around the injectors. These are typical leaky spots but don't be shy and spray it all over the intake area. You can use the solvent to clean afterward.

If there is a vacuum leak the engine will suck in the WD and you will see the RPMs rise.

Power loss can be a lot of things but another one that has come up here is cracked fuel lines in the tank or plugged up fuel filters. Basically fuel flow issues.

 

[cele0001]

1500 is just off idle. I'd suspect a vacuum leak.

Vacuum leak should have more influence at idle. As the throttle opens more, vacuum leak (if any) is becoming smaller and smaller portion of the total air and should have less influence on the mixture.

 

[69zeff65]

Low easy miles

I would consider sending the injectors out to be cleaned by a pro, soaking them and adding Techron to the tank is OK (don't over due the Techron though) but it will never get 11 year old injectors clean that have spent most of they're lives pressured up with old stale gas. Check your in tank fuel and vent hoses and replace the fuel filter while your in there.

 

[gsaddict]

Your year has the updated HES, I doubt that is causing the problem.
Do you have access to a GS911 scanner? Make sure you don't have any faults.

 

[BC1100S]

If your hard starting occurs only when cold, check to see that your fast idle (choke) cable is adjusted properly? If too much slack it could cause your hard start issue.

Edit: I see you cured that with an injector soak. Carry on.

 

[roger 04 rt]

If you buy or can borrow a GS-911, you can quickly see what the sensors and error log are saying. It will save time and a lot of diagnostic guesses. You could bring it to 2000 rpm hold the throttle steady and see what sensor is causing the rpm fluctuation.

Setting the cable tensions correctly and TB SYNC at idle and 2500 rpm is important. You mentioned that you did a TB balance. How Did you accomplish that with the rpm surging? At idle, how many turns out is each TB? Does each throttle stop screw and TPS have original blue paint or have they been "adjusted"?

It sounds as if off-idle at 2000 rpm your throttle butterflys are open different amounts. Check that there's no small stones lodged in the pulleys.

 

[blockade]

Update:

I did a vacuum leak test (by spraying WD-40 on vacuum lines/air intake joints) and got zero results. After I cleaned up the bike I loaded it up on a trailer and took it up to the local dealer. It was a surprisingly pleasant experience. I had them run the GS-911 on the bike and it threw codes for the TPS and O2 sensor. I asked them what their next steps would be. Their reply was:

• Attempt to reset TPS (again)
• Replace O2 sensor
• Replace TPS if no improvement
• Do a TBB
• Run a fuel pressure test

I told them to button it up and I would pay for the diagnostic, they handed me the key and didn't charge me a dime for their time. Awesome.

Since then, I've reset the TPS for a third time... still no improvement.

I have started looking for an 02 sensor and TPS at less than MSRP - any ideas? Found an O2 sensor on beemerboneyard but still looking for a TPS for less than $200.

Setting the cable tensions correctly and TB SYNC at idle and 2500 rpm is important. You mentioned that you did a TB balance. How Did you accomplish that with the rpm surging? At idle, how many turns out is each TB? Does each throttle stop screw and TPS have original blue paint or have they been "adjusted"?

1. Haven't touched the cable tension, it appears to be fine based on a visual inspection (both sides start moving at the same time).
2. I did the TB balance by playing with the right side BBS after setting the left side to 1.5 turns. The Right side BBS is at around 1.75 turns. The variable RPM is not a constant issue, seems to be intermitant (mainly when the bike is cold).
3. Not sure where the throttle stop screw is, haven't sought it out. Frankly, based on what I've read, I really don't want to make any adjustments to them.

Since this issue only recently came up and it started before I did a TB sync I don't believe this is part of the overall problem.

I really appreciate the ideas and input. My next steps will be to change out the TPS and O2 sensor unless someone can think of something else?

 

[blockade]

I would consider sending the injectors out to be cleaned by a pro, soaking them and adding Techron to the tank is OK (don't over due the Techron though) but it will never get 11 year old injectors clean that have spent most of they're lives pressured up with old stale gas. Check your in tank fuel and vent hoses and replace the fuel filter while your in there.

Suggestions on where I could send them? Never needed to do this before. My other "projects" have a carburetor and the solution to cleaning those it to take them apart and boil in lemon juice for an hour.

 

[roger 04 rt]

If you set up your GS-911 to log realtime values to a CSV file, start the bike, let it idle for a while and then increase the throttle to 1500 rpm and email me the file I can probably tell you if the sensors are working, O2 and TPS.

Both sensors showing errors sounds like a ground problem.

 

[blockade]

Both sensors showing errors sounds like a ground problem.

Great... an electrical issue...

I don't have a GS-911, unfortunately. The dealer pulled the codes. Would love some guidance on where to start to figure out if this is a ground problem.

Could this have something to do with my battery dying last month?

Wouldn't other sensors or electronic components be showing signs of misbehavior if this is a grounding issue?

 

[blockade]

When the cell in the battery went bad, could it have shorted out/broke the TPS and the O2 sensor?