Booster Plug??? - 1150RT-P surging querey

[flyinPhixer]

Hi Guys,

First off new to BMW's, I live in Northeast Houston, been riding forever. I have 02' 1150RTP, that sat for a bit and I bought and rode home (8 miles). Instantly noticed the surging, started getting freaked. Took it to local bike shop (non-BMW) and their two monkeys could not figure it out. Rode the bike Tupperware-less to the official BMW shop (Gulf coast/British USA), in rush hour traffic stop and go and first gear and the surging was so bad I looked like a bobble head. They merely synced the bodies, new plugs and cleaned everything out. Its better but not gone. Got caught in a massive down pour from a thunderstorm, got soaked, but ambient temp dropped close to 25 degrees and surging was almost gone (after waiting for heavy stuff to pass). I am just looking for a solution for the surging, primarily on the highway at cruise speeds.Love the bike and want to make it work better....

 

Thanks guys

[Paul Mihalka]

Hi Guys,

First off new to BMW's, I live in Northeast Houston, been riding forever. I have 02' 1150RTP, that sat for a bit and I bought and rode home (8 miles). Instantly noticed the surging, started getting freaked. Took it to local bike shop (non-BMW) and their two monkeys could not figure it out. Rode the bike Tupperware-less to the official BMW shop (Gulf coast/British USA), in rush hour traffic stop and go and first gear and the surging was so bad I looked like a bobble head. They merely synced the bodies, new plugs and cleaned everything out. Its better but not gone. Got caught in a massive down pour from a thunderstorm, got soaked, but ambient temp dropped close to 25 degrees and surging was almost gone (after waiting for heavy stuff to pass). I am just looking for a solution for the surging, primarily on the highway at cruise speeds.Love the bike and want to make it work better....

 

Thanks guys

Switch to Autolite 3923 plugs can help a lot.

 

[dirtrider]

Afternoon flyinPhixer

 

Welcome to the board.

 

First off, you really should start your own NEW thread on this as technically you are looking for help for “your” bike (hijacking the thread) not helping with the OP’s querry. (next time as you are already on this thread now)

 

 

Unfortunately the 2002 (single spark) 1150 was the worst of the surgers. Large cylinders and a lean emission complient fueling system. In fact even BMW couldn’t make them right so next version they added dual spark plugs.

 

 

You really need to get a base line before doing a lot to your bike otherwise you might be doing things that won’t or don’t help.

 

SO, first thing is remove the Motronic (#5) fuse for about 30 seconds, then reinstall it, then turn the key on (do not start the bike), then with (choke OFF) FULLY open & close the throttle twice. Then start the engine. That will do a re-learn for the TPS (throttle position sensor) so at least you know that is calibrated correctly. (if that is out of whack due to a dead battery the fueling can act strangely)

 

Next, is run 2-3 tanks of fuel through it to clean out the fueling system, clean the fuel injectors & get a good base line on how the bike acts under ALL riding conditions. Add the max amount of Techron allowed for each tank full. (that Techron is a wonderful fuel injector & fuel system cleaner)

 

OK, once you have a base line & if it still surges more than you like (probably will as most do) temporarily by-pass the fuel tank vent at that black canister hanging on the rear of the bike. To do that, open the gas cap then blow air into each hose going to that rear canister while listening for air escaping at the gas cap area (that is the tank vent hose), then trace the hoses & find the one going down to behind the R/H foot peg. Just hook the tank vent hose to the one going to behind the foot peg.

 

Next find the CCP in the fuse box & make sure it is in there & is the correct color for your bike (probably pink) (An incorrect or missing CCP can force some strange spark/fueling control & sometimes make the surging worse).

 

If it still surges next move is a bit more intense as it requires removing the R/H Tupperware & lifting the rear of the fuel tank up a bit. You need to try disconnecting the 02 sensor (connector at right rear of gas tank). Then ride the bike. (more than likely this will help your surging problem more than anything (if you have the correct (stock) CCP installed & all is right with the tank venting & fuel injectors). If the runability with the 02 disconnected makes it smooth out enough to live with you can either leave it disconnected (will hurt your fuel mileage a little) or try a new 02 sensor. (even a good 02 will probably bring some surging back).

 

Other things to check are:

 

-the valve adjustments (they have to be off a fair bit to make it surge though)

 

-fuel pressure

 

-TB balance

 

-compression

 

-for exhaust leak (pre cat)

 

If you want the best long term cure then either spend big money & have the cyl heads converted to 2 spark plugs (that is what the factory did on later 1150’s.

 

Or, just buy a Techlusion 259 aftermarket fuel controller—If a Techlusion is installed & set up correctly that will cure most of your lean surging , make the engine a bit more responsive & not kill your fuel economy.