95 R1100R very rich fuel left cylinder

[Bill51]

Hello all, I'm new to this forum and I'm looking for someone who might be able to direct me to a diagnostic flow chart for 1995 era BMW fuel injection system. I just bought the bike last week, and was successful in getting it to start, but it is only running on the right side with very rich fuel condition on the left side. There is good spark on both sides, and the throttle and high idle cables appear to be pulling and releasing properly. I have inspected the throttle body seals and they appear to be tight and without visible damage. The fuel pump starts up with the key, builds pressure, and shuts off after a short time. Anyone have any ideas? A diagnostic flow chart would be wonderful.

 

Thanks,

 

Bill

 

[T__]

Bill, both side injectors inject from the same pulse & at the same time (wired together) so that probably means the fueling computer part is OK..

 

 

First try swapping the spark plugs side to side..

 

Then

 

Try swapping the fuel injectors side to side to see if the problem follows the fuel injector..

 

If OK per the above then maybe do a compression test & a valve adjustment (either can effect the run ability of a cylinder..

 

Maybe also try plugging off BOTH rubber hoses going into the bottom of the TBI units as a problematic evap system could be allowing some raw fuel in that way..

 

Otherwise look for the basics like a plugged exhaust system or TBI throttle cables out of adjustment side to side (hook a delta type manometer between both TBI units & look for a big discrepancy side to side)..

 

Any chance the crankcase is full of raw fuel? If so the fuel can work up past the rings & make it go mighty rich (especially on the low side)..

 

Added,--maybe look for a mouse or rodent nest in the air box partially blocking one side air tube gong to the TBI..

 

Added,-- more, if nothing blatant found then maybe remove both rocker covers & verify the cams are timed correctly (sprocket arrows pointing out at TDC compression on each side)

 

Twisty

 

[Boffin]

My first stop would be to check the throttle cables are fully seated at the TBs - it is common for a cable to hang up slightly on the ferrule .

 

Andy

[Capt'n]

Bill51

 

First and foremost, Welcome to the group and I know you will enjoy solving this mystery. I have solved a few issues on my own 95 R1100RT with the help of this group and enjoy talking with many people.

I have had what I thought was a sticky throttle cable or skipping cylinder and ended up with two burnt valves. I still have not found out what caused this at ODM 17,000. After I changed the valves, I have not had any issues and have ODM 25K.

 

Keep us posted on your findings

 

Bill

 

 

[NonComp]

Remove the large brass screw on each throttle body and clean out the carbon therein with O2 sensor-safe carb cleaner and a bunch of Q-tips. These screws control the amount of air at idle, and hence effect idle speed. Before removing, turn each screw all the way and gently seat it, while counting the number of turns. Then reset when cleaned out. You will probably want to do a throttle body sync after anyway. I think the default setting for these screws is 1.5 to 2 turns out from seated.

[Bill51]

Well I think we have discovered the source of the problem, it may not be my only problem. As suggested earlier in the thread, I swapped the injectors from side to side, and the problem moved with the left injector. It now runs on the left, and is dead on the right. So I am now in the market for a good injector, any recommendations?

 

Thanks to everyone,

 

Bill

[T__]

Bill, try Beemer Boneyard

 

http://www.beemerboneyard.com/

 

You might T-R-Y filling the injector fuel inlet with some full strength injector cleaner then,, hooking the injector inlet to compressed air,, then pulsing 12volts across the injector terminals..

 

Maybe doing this a few times will clean up the injector innards & pintle/seat..

 

 

 

Twisty

[Bill51]

Well the injectors arrived today from the Beemer Boneyard, and it was a quick operation to install them into the throttlebodies. The bike fired right up and ran like a top, but there is still a lot of smoke, and what appears to be raw oil being emitted from the muffler. I'm hesitant to run the engine like this for very long due to my fear of ruining the catalytic converter. I suppose that it could still be raw gas that was left in the exhaust from the bad injector being forced out, but the engine is running too well to be a super rich mixture still being introduced.

 

 

 

I pulled the bike out of the barn and run it up and down the street a few times for perhaps 2 or 3 minutes, finally twisting the wick a little bit and she pulls pretty hard, I was impressed. There are no loud noises, but there is a slight ticking noise, and never being around a beemer, I don't know if it is normal or not.

 

 

 

Is there something that would allow enough oil into the exhaust that some would be expelled as a liquid form the muffler? It would seem that a broken oil ring wouldn't allow more than would be burned in combustion. Anyone have an idea? If not, I guess my next step will be to start pulling the heads and cylinders down.

 

 

 

Thanks for considering,

 

Bill

[T__]

Bill, while whatever is in the exhaust system is probably not the best for the cat you never hear of any plugging cats on the BMW’s.. Maybe ineffective but not plugged.. The metallic honey comb inside the cat is pretty hearty..

 

On your ticking,, those BMW 2 cylinder bikes have a fair amount of ticking noises from the solid valve lifters,, to ticking fuel injectors,, to timing chain rattle,, to transmission neutral gear rattle,, to the R/H throttle plate rattling in the TBI throttle bore..

 

Remember you are sitting right on top of an exposed cylinder engine.. Go open the hood on your car/truck then revv the engine then listen to it..

 

 

A good base line is to find another like BMW then go ride it a while.. Or have someone with a like bike ride yours..

 

Just do a search in the archives for engine noises & you will find plenty,, then do a search for blown up engines (you won’t find many or maybe none at all)..

 

Added: when a cylinder doesn’t fire correctly a fair amount of oil gets up past they piston rings..

 

You might also check your air cleaner box.. The engine vents into the lower air box & there is a little plastic valve on the L/H lower rear corner to drain it.. You might open that valve & see what comes out..

 

 

Twisty

 

[NonComp]

How many miles on this bike, Bill? I wonder if the stuff in the muffler is residual stuff from the injector problem? How is the oil level? Has the bike been overfilled? There is a drain in the left-rear corner of the airbox. Remove it and see what comes out.

 

The ticking may be coming from the right-hand throttle body. The shaft may be warn and you may be hearing the butterfly clicking.