2009 Stelvio, after warm up idling on what feels like a single cylinder

[motowfo]

This is a non ABS bike so there is only a single lead possibility to connect my VDSTS to to try and figure things out...
Starts immediately (I know, it's not supposed to do that!) when cold

After about 4 or 5 minutes of warm up, it starts to idle on what feels like 1 cylinder

If I give it gas, the rpm's pick up and it runs great...

Back to idle with what again feels like 1 cylinder.

If I let it cool off (cold start) it will repeat the same results.

What I have done so far:

1. Checked valve adjustments
2. Replaced new fuel with even newer non-ethanol
3. Swapped spark plugs
4. Did the "turn out the lights and look for sparks" thing. No arcing detected (SP Covers off)
5. Swapped injectors from side to side... seemed to be a small improvement to "mostly" idling on one cylinder but still irregular idle after warm up.
6. Attempted to attach VDSTS with my old WINDOWS XP machine that has worked in the past, unable to connect to ECU
7. Attempted to attach VDSTS with my Windows 7 machine, unable to connect to ECU.

(Only other 'symptom' is the heated grips have quit working but all of the wiring and relays have been checked and appear to be ok)

My current thought is ... ECU needs to be reflashed but maybe you have a different opinion or could suggest further diagnostics....?

OR????

 

[john zibell]

I hate to ask, but is the version of VDSTS for the 5AM? If so have you checked the integrity of the diagnostic cable and comm ports? VDSTS is no longer supported and there could be an issue with a failed interconnecting cable.

 

[motowfo]

Been on TechResearch Tech Support all of this afternoon...

Yes , 5AM has been supported ... (I've connected to it in the past... just seems to be an issue now)

PS... Hi John!!!!

 

[WayneOrwig]

Have you checked the throttle body balance?
Have you tried to clean out the stepper motor passages?
When it is idling on one cylinder, shut if off and pull the plugs nd inspect the ceramic.

Sounds like you a bum driver or cable.

If BOTH grips aren't heating, odds are, BOTH wires or grips are actually bad. Or the ground for them is bad. The dash actually has two outputs for the grips and treats them almost like independent circuits. The ground may be common though.

 

[motowfo]

I'm bumping this thread with additional info...

Finally got VDSTS to connect after support from TR...It was a computer issue.

Checked TB Balance - all is good
Reset TPS - no change.

Out of desperation, I pulled the front body and swapped coils from side to side. This seems to improved the warm idle but now the bike is "hunting" from 1000-1200 rpm at idle and the off throttle response is finicky (I have to pump it like the Harley riders do before the engine smooths out)

Another board seems to think this is because I have not done the roller rocker conversion on my 35k miles Stelvio. From my understanding 95% of the 09 Stelvios were fine... I did check local "dealer" and they seem to be pretty clueless as to what the heck I'm talking about when I mention the roller rocker setup.

I have a set of new coils and wires that I'm planning on putting on this weekend to see what difference that will make.

I will continue to post the results until I come up with a solution...

NOTE: I saw a posting from PEDRO that has the same symptoms as to the single cylinder running except his single cylinder issue was an arcing plug wire. I am not able to identify that as a root cause and it wouldn't really explain to me why that when the bike is cold, all is good. Once it reaches operating temp is when the idle goes wonkers...

Open to all suggestions... I'll probably pull the left side cam chamber this weekend to see how the tappets look. Assuming they are OK... what next?

 

[canuck1969]

You may have a stuck stepper motor. The hunting may be caused by air surging. If you can access the hose to the stepper from the airbox, pull it off and plug the end to the stepper. If the surging stops they you have a screwed up stepper. It may be diverting air to one side more than the other. I would start there.

I agree, when it gets hot the plugs should not make a difference, but I have seen stranger things on these bikes. Pull the plug boots just to look at them. If there are any white marks wrap them with electrical tape and see what happens.

As an aside, I responded to your PM concerning the kit that is needed. i could not post the service bulletins to the PM to determine the kit type so I have added it here. There are a few different variations but they all have the same guidelines on how to determine the kit. Hopefully it will be a B kit as that will be a lot easier. C will required valve spring shimming and removing the head.

 

[motowfo]

You may have a stuck stepper motor. The hunting may be caused by air surging. If you can access the hose to the stepper from the airbox, pull it off and plug the end to the stepper. If the surging stops they you have a screwed up stepper. It may be diverting air to one side more than the other. I would start there.

I agree, when it gets hot the plugs should not make a difference, but I have seen stranger things on these bikes. Pull the plug boots just to look at them. If there are any white marks wrap them with electrical tape and see what happens.

As an aside, I responded to your PM concerning the kit that is needed. i could not post the service bulletins to the PM to determine the kit type so I have added it here. There are a few different variations but they all have the same guidelines on how to determine the kit. Hopefully it will be a B kit as that will be a lot easier. C will required valve spring shimming and removing the head.

Thanks JOE!!!!!

Good news... I have the FLOATING type so looks like KIT A!!! Don't have to mess with valve springs and the like... YEAH!!!!

Strike the above!!! It's a C kit... ugggg

 

[canuck1969]

Scared me for a second.....couldn't figure out how you had a motor that would have taken an A kit.....

C sounds about right for your year although I have heard of some B but they were rare. Just double check to paint mark in the TSB to be sure.

If you are doing the work yourself, it won't be that much harder than the A kit, but you will need the valve compression tool or be very creative to get the shim in. If you end up doing it let me know and I have a step by step procedure for the C kit that someone else put together

 

[motowfo]

I was thinking about cutting the shim in by cutting it in half and inserting 1/2 at a time

I pulled left side to check flat cams... 32 k Miles... Not as bad as I thought but... going for the C kit...

 

[canuck1969]

Your still good. That much wear would not cause any running issues, but should be fixed. My coating was completely gone and the bike ran flawlessly, and still continues to run flawlessly after the conversion at 50,000 KM. Don't believe everything you read on the internet.

 

[motowfo]

Latest update, the local dealer submitted the info to Piaggio and has receive preliminary approval for a roller cam upgrade. I will happily pay the labor while Piaggio supplies the parts under their special warranty.

Hoping to hear that the kit is in some time in the next week or two... Now on to reassembly!!

Thanks to all for their comments and suggestions!

 

[motowfo]

Thanks to all (Mr. Roper, Mr. Zibell, and canuck1969 among others). Issues resolved...

Rollerized, found pinhole in the left cap (under the wire cover) that was shorting out (aka sparking) causing the miss. All pretty much back together and waiting for a good test ride. Only issue (new one) is how to get into the glove box... switch clicks but no unlock action... something I did in assembly...