Author Topic: Stelvio 1200 NTX rough idle  (Read 1148 times)

Offline whitewolf

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Stelvio 1200 NTX rough idle
« on: May 21, 2025, 10:04:28 PM »
I have some problems with rough idle on my 2014 Stelvio NTX, it rides well but it's pretty annoying, especially at slow speeds
I did already:
- valve adjustment (no improvements)
- throttle body sync (it didn't fixed the issue but big improvements over 4k RPM)
- replacing the spark plugs and caps, also minor maintenance work like cleaning air ducts and airbox
- lambda sensors check

I tried to test which cylinder it's not working well, to isolate the problem, so I tested removing spark plugs connectors then injector connectors, one by one, while the engine is idle, and I had a big surprise: with only one cylinder working the idle is smooth, but as soon as I connect the other cylinder the idle goes lumpy, with RPM variation and tending to stall

From similar topics I red that changing the map could solve the issue. I bought the bike with this problem, thinking it's an easy fix, so I can't tell if it's the factory map or it was altered before. Could someone please point me to where may I download a better map for this ECU, or could someone share a working map?
Also, I would highly appreciate if someone had this issue before and could recommend a fix

Offline Huzo

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Re: Stelvio 1200 NTX rough idle
« Reply #1 on: May 22, 2025, 12:06:26 AM »
So will it idle smoothly on either cylinder with other disconnected ?
Could you shoot  a video and post it ?
When you are operating on one cylinder, is the rpm the same for both and what is the figure ?

Offline whitewolf

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Re: Stelvio 1200 NTX rough idle
« Reply #2 on: May 22, 2025, 03:07:24 PM »
yes, the idle is smooth on either of the cylinders, with other one disconnected, the RPM seem to be pretty much the same for both. It gets lumpy when both fires, and the RPM varies from under 1k up close to 2k

I'll try again, with GuzziDiag connected, to check parameters, and I'll shoot a short video then

 

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