2017 Stelvio running issues

[Twin AH]

Having a few issues with my 2017 Stelvio NTX as of late that may require Mark ( aka Beetle )

Where are you Mark.

Regards.

[pete roper]

I don’t think Mark posts here. What’s it doing?

[Twin AH]

Hey Pete thx for chiming in......... tried to get ahold of Mark with no avail.

I have a bit of response from others over on Wild Goose Chase.

At this point its starting ok but when you try and hold a steady rpm from 2k all the way through to about 5K it surges and wanders all over the place.... cant hold steady throttle when at load(moving) either??

Burning fuel like a bugger and smells the part?and is not making much power as I found out having a 100kph roll on with my Brothers stock same year Stelvio... he left me for dead??

Was hoping someone might have had something like happen abruptly to their lump in the past.......... also hoping NOT to randomly starting plowing new parts in it at random in hopes of getting lucky.

PS          None of the dealers or shops that I have spoke over the years know anything about these machines unfortunately........... for me.

[pete roper]

Ah, found the info on WG.

First thing to check, as suggested, would be the plug caps. Get it in a darkened garage and take the plug lead covers off. Start the bike and look and listen for the spark *Snapping* to earth at the rocker cover. Even if you can’t see it you should be able to hear it.

When you last serviced it, how did you remove the plug caps? If yo pried, pulled or levered them from above you will almost certainly of damaged them. They tend to tear at the right angle where the cap turns to meet the lead. Once that has happened it doesn’t take long for the spark to start earthing out. It may not happen immediately though so don’t be surprised if it started mid ride.

The way to remove the caps on the 1200-8V’s is to get a long, thin, flat bladed screwdriver and insert it through the cooling tunnel in the head just above the exhaust manifold. Poke around and you’ll feel the rubber of the cap. Hook the tip of the screwdriver under the bottom of the cap and lever it up, off the plug. Once it has unclipped from the top of the plug, then, and only then, do you pull it up from above.

The excessive fuel use and unburnt fuel smell will be from the uncombusted fuel passing through the non-firing cylinder. If you are running the original pipe, or an aftermarket one with a catalytic converter, the cat may well of been damaged by the unburnt fuel combusting in the cat. Look for discolouration at the front of the exhaust can.

It is very unlikely it is an ecu or mapping problem. The W5AM is pretty much unbreakable and the files can’t corrupt themselves. It will have a physical cause and plug caps are the most likely one.

Edited October 20 by pete roper

[activpop]

Pulling the plugs and looking at them might give a hint as to what cylinder is misfiring.

[Twin AH]

3 hours ago, pete roper said:

Ah, found the info on WG.

First thing to check, as suggested, would be the plug caps. Get it in a darkened garage and take the plug lead covers off. Start the bike and look and listen for the spark *Snapping* to earth at the rocker cover. Even if you can’t see it you should be able to hear it.

When you last serviced it, how did you remove the plug caps? If yo pried, pulled or levered them from above you will almost certainly of damaged them. They tend to tear at the right angle where the cap turns to meet the lead. Once that has happened it doesn’t take long for the spark to start earthing out. It may not happen immediately though so don’t be surprised if it started mid ride.

The way to remove the caps on the 1200-8V’s is to get a long, thin, flat bladed screwdriver and insert it through the cooling tunnel in the head just above the exhaust manifold. Poke around and you’ll feel the rubber of the cap. Hook the tip of the screwdriver under the bottom of the cap and lever it up, off the plug. Once it has unclipped from the top of the plug, then, and only then, do you pull it up from above.

The excessive fuel use and unburnt fuel smell will be from the uncombusted fuel passing through the non-firing cylinder. If you are running the original pipe, or an aftermarket one with a catalytic converter, the cat may well of been damaged by the unburnt fuel combusting in the cat. Look for discolouration at the front of the exhaust can.

It is very unlikely it is an ecu or mapping problem. The W5AM is pretty much unbreakable and the files can’t corrupt themselves. It will have a physical cause and plug caps are the most likely one.

OK then............ tomorrow I will tear into it and replace plug caps with new as well as plugs.

Others have stated its probably a failed TPS.

Your thoughts on that?

[Twin AH]

3 hours ago, pete roper said:

Ah, found the info on WG.

First thing to check, as suggested, would be the plug caps. Get it in a darkened garage and take the plug lead covers off. Start the bike and look and listen for the spark *Snapping* to earth at the rocker cover. Even if you can’t see it you should be able to hear it.

When you last serviced it, how did you remove the plug caps? If yo pried, pulled or levered them from above you will almost certainly of damaged them. They tend to tear at the right angle where the cap turns to meet the lead. Once that has happened it doesn’t take long for the spark to start earthing out. It may not happen immediately though so don’t be surprised if it started mid ride.

The way to remove the caps on the 1200-8V’s is to get a long, thin, flat bladed screwdriver and insert it through the cooling tunnel in the head just above the exhaust manifold. Poke around and you’ll feel the rubber of the cap. Hook the tip of the screwdriver under the bottom of the cap and lever it up, off the plug. Once it has unclipped from the top of the plug, then, and only then, do you pull it up from above.

The excessive fuel use and unburnt fuel smell will be from the uncombusted fuel passing through the non-firing cylinder. If you are running the original pipe, or an aftermarket one with a catalytic converter, the cat may well of been damaged by the unburnt fuel combusting in the cat. Look for discolouration at the front of the exhaust can.

It is very unlikely it is an ecu or mapping problem. The W5AM is pretty much unbreakable and the files can’t corrupt themselves. It will have a physical cause and plug caps are the most likely one.

 

7 minutes ago, Twin AH said:

OK then............ tomorrow I will tear into it and replace plug caps with new as well as plugs.

Others have stated its probably a failed TPS.

Your thoughts on that?Also machine has always had a Mistral can no cat but still has evap system from factory.

 

[pete roper]

I’d be very surprised if it was the TPS. I’ve only ever replaced one and that Thad been submerged at some point!

You can check it fairly easily using Guzzidiag. Just look at the value as you open and close the throttle. Any sudden jumps or drops will be immediately obvious.

[Twin AH]

Thx to all for commenting.

 

Ciao for now

[Twin AH]

OK............... all new plug caps and all tidy on both barrels.

The bad news.................. still doing exactly what it was doing before replacement of caps??

Any other ideas all?

[Pressureangle]

If it was any sort of primitive automotive system I'm familiar with, I'd say to check connection to and function of the engine/intake air temperature sensors. If they fail they can make it run 'on choke' forever. 
Does it run any better cold than warm?
Also hard to check here, but if a piece of debris holds an injector open it dribbles fuel all the time. Pretty common in earlier car stuff, and both EFI bikes I have desperately needed their injectors cleaned. One didn't seem to dribble and the other I haven't run yet. 

I suppose you could pull the injector and see that it primes properly, then should not produce any more fuel at the tip. If it's leaking bad enough to produce your symptoms it should be obvious.

Edited October 20 by Pressureangle

[PJPR01]

29 minutes ago, Twin AH said:

OK............... all new plug caps and all tidy on both barrels.

The bad news.................. still doing exactly what it was doing before replacement of caps??

Any other ideas all?

Did you replace the spark plugs as well or just the caps?

As suggested over on WG...might as well repeat it here as well since the post is in both places.

Fuel Filter?  When was it last replaced?

Bad gas...did you try adding any additive or drain/siphon and refill with good gas?

Just have to go slowly and methodically thru the possibilities. before getting into the low probability ones.

[Tomchri]

Still burning way to much fuel ? My fuel regulator decided to stay open. Probably seldom, BUT. And yes they can consume a lot.

Cheers Tom.

[pete roper]

39 minutes ago, Twin AH said:

OK............... all new plug caps and all tidy on both barrels.

The bad news.................. still doing exactly what it was doing before replacement of caps??

Any other ideas all?

It’s still showing all the signs of not firing erratically on one cylinder at least. The lack of power, the very high fuel consumption, the smells unburnt fuel, all point towards one or both cylinders only working sporadically.

The plug caps are a known problem area so it was a logical place to start. Now you need to go deeper.

Does the dash blank out or the lights flicker when it’s surging and misbehaving? Try hooking up a strobe to the plug leads and riding it to see if and when the spark is dropping out. 
 

Check and swap around the relays and clean all the fuses, including the ones under the small triangular panel under the seat on the RH side. Clean the battery posts and the cable connectors and ensure the earth strap is clean and securely attatched to the mount on the gearbox inboard of the starter motor cover.

With the bike on its centrestand and the ignition on turn the handlebars slowly from lock to lock and see if the lights or dash flicker.

Something is causing it to drop at least one cylinder. It’s simply a process of elimination to work out what it is.

[Twin AH]

Just caps at this point.......... new plugs should arrive tomorrow.

Original fuel filter. Yes did give it a good does of injector cleaner a couple weeks ago(that was my first thought on what it might be)

I'm thinking from time to time now the way it is acting that has anyone had a vacuum leak some where in the system that could be causing all this?

It still has all the original pollution control/evap can ect.

 

Just trying think of all the easier tests to do first is all.

Ciao