Stutter at idle

[TonyRS]

I've searched the forum in case forum police chimes in:)

 

My R1100RS starts fine and pulls away without issue. But when warmed up, the idle stutters. It's random stutter and sometimes it feels like it just might stall the engine(it hasn't yet).

 

Recently: new spark plugs, valves adjusted, new air filter, GS intake and GS CCT, TPS zero-zero'ed, BBS adjusted about 2 turns out and TB's synced.

 

Where do I look next?

[Jim Moore]

What's your idle rpm? The spec is for 1050 +/- 50, but I prefer a little higher. I always set my idle at 1200-1300.

[dirtrider]

I've searched the forum in case forum police chimes in:)

 

My R1100RS starts fine and pulls away without issue. But when warmed up, the idle stutters. It's random stutter and sometimes it feels like it just might stall the engine(it hasn't yet).

 

Recently: new spark plugs, valves adjusted, new air filter, GS intake and GS CCT, TPS zero-zero'ed, BBS adjusted about 2 turns out and TB's synced.

 

Where do I look next?

 

Morning TonyRS

 

When did the problem start? This might help us pin it down.

 

You have covered most things--

 

What year 1100RS?

 

Your problem might be a dripping fuel injector or injector with a spray pattern issue (maybe try running a couple tanks of fuel with a good dose of Techron in it).

 

Or could be an o2 sensor that isn't working properly (lazy or poisoned)

 

What exhaust system are you running? If not stock that can effect the exhaust reversion & effect idle fueling.

 

Also, try going back to the stock CCP. Or even try removing the CCP completely to see if that straightens the idle out.

 

 

[TonyRS]

Jim: My idle is right around 1100rpm when warmed.

 

DR: The bike is new-to-me this summer; it's done that from start. I ran one tankful of Techron two fill-up ago. I'm running stock exhaust. Is there an easy check for O2 sensor?

 

I'll try go back to stock(YELLOW) CCP and see if that helps.

[dirtrider]

Jim: My idle is right around 1100rpm when warmed.

 

DR: The bike is new-to-me this summer; it's done that from start. I ran one tankful of Techron two fill-up ago. I'm running stock exhaust. Is there an easy check for O2 sensor?

 

I'll try go back to stock(YELLOW) CCP and see if that helps.

 

Afternoon TonyRS

 

No real easy way to test the o2 sensor (even removing & bench testing with a propane torch is non conclusive).

 

BUT/ there is an easy way to see if the o2 sensor might be causing the problem-- just remove the CCP completely, then remove fuse #5 for about 5 minutes, then reinstall fuse #5, then ride the bike . Removing the CCP deactivates the o2 sensor from influencing the fueling control. (Removing CCP forces open loop fueling control)

 

If the idle problem is then gone that means the idle fueling was off (could be a bad o2 sensor or other fueling issue)

 

 

[roger 04 rt]

Tony,

Follow DR's advice but for the future note that zero=zero isn't the right procedure. At zero degrees open the TPS should be set to 250mV.

[TonyRS]

DR: I'll try removing the CCP and reset fuse 5. I'll report back on results.

 

Roger: I read through your posts after I'd already done my zero-zero and set it at 385mV. Next time I touch the TPS, I will set it to 250mV as what you said made sense to me.

[TonyRS]

I just wanted to wrap up this thread as I don't like it when an issue is left dangling.

 

After the bike was warmed up I pulled the YELLOW CCP as suggested by DR. Immediately the stutter at idle greatly lessened and the bike felt smoother. However it felt the midrange power was bit down.

 

I rode home and swapped in the GS CCP and pulled fuse #5 for couple of minutes. The idle stutter is just about gone and the midrange power is back. I'm very happy with this.

 

So what changed since my original posting? I know the original RS CCP(YELLOW) doesn't work with the GS intake tubes. Stutter city. Maybe I didn't pull the fuse #5 long enough when I stalled the GS CCP and I did today? But I know now that with the GS intake tube, it needs GS CCP to work on my RS.

 

So it isn't a scientific closure on this issue but closure for me. I'm happy with the way the bike is running and the enhanced mid range power from GS intake swap. And no more idle stutter issue!