Missfireing on the right.

[Big Nick]

HI there Im big Nick, I got a 1998 BMWR1100RS, missing on the right cylinder, so I swaped plugs,leads,injectors, replaced the fuel filter, did the hall sensor rewire, checked valve clearances, got spark, fuel, 200psi on the right and 150psi on the left. But only the left wants to fire reliably. Could it be my onboard computer? there looks to be earth wires on the bottom of the throttle bodies, any clue to there reason for existance? Any advice at this point would be appreciated.

Edited May 10, 2020 by Big Nick
added fuel filter replacement.

[dirtrider]

58 minutes ago, Big Nick said:

HI there Im big Nick, I got a 1998 BMWR1100RS, missing on the right cylinder, so I swaped plugs,leads,injectors, replaced the fuel filter, did the hall sensor rewire, checked valve clearances, got spark, fuel, 200psi on the right and 150psi on the left. But only the left wants to fire reliably. Could it be my onboard computer? there looks to be earth wires on the bottom of the throttle bodies, any clue to there reason for existance? Any advice at this point would be appreciated.

Afternoon Nick

 

The computer (Motronic) sparks both sides from the same coil & controls both fuel injectors as a single function.

 

Have you absolutely, positively, thoroughly verified that the right hand throttle cable is FULLY seated in it's adjuster furrel  at the R/H throttle body ???????????????

 

If the R/H cable isn't properly seated it holds the throttle plate open so more air flows in but there is  no added fuel to go with all that air so you get a dead cylinder.  

 

That is the number one reason that the right hand cylinder doesn't fire at idle on the BMW 1100 engines. 

 

[dirtrider]

Afternoon Nick

 

There looks to be earth wires on the bottom of the throttle bodies, any clue to there reason for existence?-- Probably only on the L/H side throttle body, that would be the redundant ground  for the TPS.

 

 

[Lowndes]

Nick,

 

You might have a clogged injector.  It's very easy to check, leave the fuel line and wires connected to the injector and remove the injector from the TB.  Hold the injector in a clear plastic soda bottle and crank the bike.  You should see a strong pulse of fuel spray in the bottle while cranking.  See if the other side looks the same.  

 

In addition to the fuel filter in the tank, each injector has a tiny strainer little bigger than a grain of rice in the inlet side.  Easy to check, pull the retainer clip from the fuel line on top of the  injector and get a magnifying glass to  look at the screen in the filter.  

 

DirtRider's advice on adding Techron concentrate to the fuel has really helped me on several occasions.  You might try that, too.

 

These are Bosch injector filters,  almost impossible to remove without destroying them.  These are new replacements:

 

 

 

 

This is a '99 RT injector but similar to the R11S.  The retainer clip and the electrical connector are off but this is the way to check the spray in a bottle:

 

 

 

 

[dirtrider]

34 minutes ago, Lowndes said:

Nick,

 

You might have a clogged injector.  It's very easy to check, leave the fuel line and wires connected to the injector and remove the injector from the TB.  Hold the injector in a clear plastic soda bottle and crank the bike.  You should see a strong pulse of fuel spray in the bottle while cranking.  See if the other side looks the same.  

 

In addition to the fuel filter in the tank, each injector has a tiny strainer little bigger than a grain of rice in the inlet side.  Easy to check, pull the retainer clip from the fuel line on top of the  injector and get a magnifying glass to  look at the screen in the filter.  

 

DirtRider's advice on adding Techron concentrate to the fuel has really helped me on several occasions.  You might try that, too.

 

These are Bosch injector filters,  almost impossible to remove without destroying them.  These are new replacements:

 

 

 

 

 

 

This is a '99 RT injector but similar to the R11S.  The retainer clip and the electrical connector are off but this is the way to check the spray in a bottle:

 

Evening  Lowndes

 

Nick already checked the injectors as he swapped the injectors side to side & the problem remained on the R/H side (didn't move with the injector).