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Huzo, no the bike does not have a step motor as far as I know.
It must, at it needs some method of controlling idle air. I presume it is another unserviceable component of the combination ECU/throttle body.
V11's and many Guzzis run just fine with IFE and no stepper motor as do many many Ducati's with EFI. They use air bypass screws and throttle plate stops working in concert for idle control together with fuel and ignition mapping of course. Not sure what the OPs bike uses but if it does use a stepper motor that would be a good place to start looking. Electrical connection first I'd suggest. Phil
Can't speak the V11 sports, obviously the Cali V11's and the 2 TB smallblocks both used physical fast idle levers.The CARCs all used steppers.I've been told the 1TB smallblocks use a bypass valve or something integrated into the throttle body.But no matter what the solution the ECU can't automatically adjust idle speed unless it has some method of controlling air right?Bypass screws or whatnot are fine if they are adjusted and set for certain conditions, but what happens on other conditions? And there are no physical adjustments on the 1TB units.Oh screw this... See link, download PDF, SEE PAGE 7, Stepper Motor:https://www.guzzitek.org/documents/injection/ECU_MIU-G3_Training.pdfHa ha sorry got tired going from memory...
Yep and so does the V11 Sport and the Daytona and Centauro. The point I was making is many older EFI engines control the idle without a stepper motor so it's not a mandatory thing to have. When the engine is cold you can use the fast idle lever or the throttle to maintain an elevated rpm for warm up. My V10 Sport starts and idles without the fast idle lever or throttle at any temps from 10 deg C to 40 deg C. Then again it's been mapped by me not the factory.Ciao
Ahhh, ok I see where you're going. But it's not in conflict with my logic. An ECU cannot control cold and hot idle speed without something like a stepper/bypass. Now maybe there's an exception somewhere that uses say ignition timing or something to affect idle speed.But absent an automatic/ECU controlled system there's a mechanical method that's adjustable. I knew the 1TB didn't have that and seemed to "control" idle speeds therefore there has to be a mechanism.Your lack of need got the fast idle lever for cold streets suggests richer mapping and probably idle speeds that vary somewhat from spec (neither of which are necessarily problematic). EFI does have an advantage over carburetors here in that it can enrichen mixture for cold starts without needing to mechanically limit air for the same result or open an additional fuel passage etc. But it still doesn't actively control the speed without additional input if that makes sense.Anyway op, let us know what you find.
Hi and thanks for all your replies. I am sorry I cannot contribute to the stepper motor question as my knowledge is very limited on this, I just did not find any mention of such thing in the manual and assumed the bike does not come with one. Coming back to the issue however, I think that @vintagehoarder must have had the point. I removed spark plug caps and spark plugs this morning for inspection. I am attaching the images of each. There is a significant difference in how they look. It's the left hand side cylinder which looks much more black/oxidised. More interestingly however is the fact that upon reassembly and starting up the bike again the spluttering, inconsistent idling and cut-offs have now gone. So I am probably looking at an intermittent problem caused by the spark plug cables ... I will try to search this forum for information about problems with this year models and see what I can find.
So I am probably looking at an intermittent problem caused by the spark plug cables ... I will try to search this forum for information about problems with this year models and see what I can find.
Those plug gaps both look big in the photos . did you re gap them before re installing? I think .027 is recommended.
Thanks for all the good advice.I will be first of all changing the spark plugs. If you look close at the image below, there is a black residue/banding on the top of the spark plug where it connects to the plug cable. I wonder if this might be affecting the connection under certain temp/humidity settings thus causing the problem. I will not be going down the route of changing plug cables at this stage. I do however wonder as some of the posts here suggest, whether I have to personally adjust the plug gaps on the new spark plugs I receive ??I mean, first of all I would not know how to do this and secondly I would assume that one of the numbers in the spark plug name (NGK CPR8EB-9 in this case), refers to the gap the plugs come with. Is it really the case that Moto Guzzi expects the owners to adjust the gap of the spark plugs when replacing them with the same exact model as OEM?
Lots of nope here.As I've said, my 2013 has done this since new, with the original map, with an updated OEM map, with BRAND spanking new spark plugs, with new spark plug caps... the occasional cold start stumble for a few minutes till warm is the only symptom mine has ever had and it goes away as soon as it is warmed up. Now why yours didn't seem to do it much before, I have no idea.No I don't think that residue means jack. But then again I really don't believe that stumble is just an ignition misfire.As for spark plugs, no, the gap is not in the code. The code is strictly about heat range (length of insulator), thread diameter, whether it's a resister plug or not etc. Though spark plugs often will be near or close to the correct gap when purchased, they are not designed for just one motor and therefore they might be wildly wrong. A simple wire feeler gauge is used to measure the gap, and it is adjusted by very VERY gently bending the side electrode that protrudes out to vary the gap.But fresh plugs aren't going to hurt anything.
Thanks for that Kev, message received. The way I see it it will be hard for me to pinpoint the problem since this seems to only occur on very rare occasions and disappears before I have the chance to put the diagnostic tool on the bike. As I said earlier, this time the problem stopped as soon as I took out the plug cables and put them back on again. Correlation is not causation of course, so I need to see if this will be relevant next time this happens. On with changing the spark plugs then. I measured the gap on a pair of brand new ones and they come at 0.75mm. The user's manual says gap should be 0.6mm-0.7mm, so I guess 0.65mm is what I should be aiming at, right?