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2012 Norge Stepper Motor

abbienormal

abbienormal

High Miler
GT Famiglia
Joined
Nov 29, 2008
Messages
899
Location
Niles, OH
Looking online and talking to those who know, the current guess is the popping under 4,000rpm is from the stepper motor for the inlet. Doing some searches on the bike and in the parts manual I'll be danged if I can find it. Do I have one and if so where the heck is it? I have even had the airbox lifted up while replacing the oil pressure switch and no clue where it is. Or just tell me what hose to plug. If I don't have one I'll live with the popping as it does it less than my Mini.
 
Thanks John. Now the NEXT time I have the tank off I'll see what hoses I want to play with. I can also look in the shop manual and see the hose routing if it has it now that I know what I am looking for. My tank is a bugger to get the back bolt in.
 
Rudy you might be able to access the hose to the stepper from the RHS of your engine - just above and to the right of your RH throttle body. A pair of Long Nose Pliers might get it out for you (unless you have Jimi Hendrix fingers...) and you can stop it with an 8mm screw, or similar to see if this cures your problem. Only caveat on this is that you will need to feather the throttle when cold as it will be inclined to stall unless the engine is warm.
 
Three things will generally cause popping on the overrun, though if it is sub 3600 RPM, it is most likely the stepper. The others would be super lean on the overrun; super rich on the overrun or some leaks in your exhaust system. However one thing at a time...
 
I have the fuel tank off again due to a new problem that I am still trying to figure out what it actually is. I see the hose and I could have reached in and crimped it with some hemostats had I seen your post prior so thanks. I can play with it to see if it helps but popping vs cold bloodiness is kind of a wash so I may leave it pop. First I have to get it running again. When I know more I'll post but for now all I know is it quit running after about 30 miles and fuel is in the air box. Right side fires, left doesn't. In 44 years of riding this is the first time not involving an accident that my bike came home on a tow truck. Oil was my first thought since that was what I worked on last but pulling valve covers all looks fine and the engine turns over fine even right after it quit. Left plug was wet. Right normal.
 
I changed wires and caps when I got the bike. I am no fuel injection wizard but why would that make a pool of fuel in the air box? I plan a leak down test first then a spark test. Can I turn the engine over with the tank off to check spark? I know I'll get a service warning on the dash due to no fuel pump and who knows what else.
 
if your left plug is wet, fuel for sure and probably because the plug cap is having a small holiday. try and start it in the dark with the plug cover off and you may see where the holiday is coming from. others have used a different NGK plug (please chime in if you know) that is not as fragile as the original equipment.

If enough fuel has gone into your engine, your oil may also be contaminated - petrol is not a good lubricant!
 
You may have a stuck injector on the one side. That could explain both the wet plug and the fuel in the air box. But that is just a guess.
As to the stepper motor, a nice mod is to put a valve in the line connecting the stepper to the air box, that allows you to turn the stepper system one or off.
 
I liked the stuck injector theory. Here is where I am at. As I said the I was test riding the bike. I had just stopped on the side of the road and let it idle while I checked for any oil leakage. Seeing none and everything running fine I turned around to head home. Going down a straight almost flat road right only about 1/4 mile after stopping I heard it cut out then saw the red light on the dash and immediately hit the kill switch though it may have already been stopped. I think I hit the kill switch before I pulled in the clutch but not sure.
I have the valve covers off and all looks fine., Valve clearances are in spec and oil is everywhere. As I said, there was a pool of fuel in the airbox and when I got it to fire only the right exhaust got warm (didn't run it but a moment as the red light and Service came up on the dash.) The only code I on the dash is 27 which is ECU ground from what I see. Bike was running perfectly but doing a leakdown I get 4% right side and 27% left side. All coming out the exhaust from what I can tell but I still have normal valve clearance. Thinking (hoping) maybe something washed under the valve with all the fuel. You can smell the fuel as the air comes out the exhaust. I pulled the left injector and I cannot get 100psi of air to go through it. Have not checked spark as I think I need to reinstall the airbox and tank to crank the engine and get spark.
This bike has 7,400 miles on it and I changed the plug caps, plug wires, iridium plugs.
I am open for suggestions. I really don't want to pull the head if not needed. I see no way a leaking exhaust valve would flood the airbox with fuel. I ran into this on another bike years ago where I thought there was no reason for the leak down on one cylinder and after pulling it apart even though it ran fine I found nothing. That was exhaust valve also. Yes I put in new then but no noticeable change in running.
What is really sad was my plan when I got home was to order a new seat, pegs and tank bag. Now I am not so sure. I may spend the money on suspension for my Suzuki instead.
 
From that leak down test your left exhaust valve may well have something stuck under the seating area, or it has burned even though clearance is good. In any case, it will be off with its head to correct that issue. To confirm the injectors I'd send both to RC engineering or other injector reconditioning facility. As for the ECU error, check the ECU ground point. Hopefully the ECU isn't toast.
 
Abbie, dont get pissed, but it looks like your testing is helter skelter all over the place. It also looks like your fiddling is making it worse and you are now conflating and creating new problems. I'm very new to MG, but an old wrench. Slow down and isolate, separate good from bad.

FYI, the stepper motor is basically idle control and is on the throttle bodies. Its basically just a shaft that pushes on a cam in the throttle linkage and controlled by the ECU.

From what I see you have:
1. Popping at low RPM (original problem) - is this intake pop or exhaust? On accel or decel or steady running?
2. Wet Left (#1) spark plug & raw fuel in exhaust - is either bad plug, cap, wire coil or poser to coil (ECU) IMO, is priority #1.
3. ECU warning saying bad ground - This may be a false reading or fluke, try to reset. If it doesnt, you need to run this down and is likely part of your no spark issue.
4. Leak down tests - dont make sense to me and LD tests are often done wrong. IMO are a waste of time. What are the compression readings? When you do it, pull the Fuel pump plug and crank at WOT with both plugs removed. Otherwise you will get wacked readings.
5. Oil Everywhere - WHY? did you run it without the valve covers on? or did you have an oil leak?

I dont want to insult you but I would stop where you are man. Regroup. Why would you do a leak down test? why blow air through fuel injector? It opens with ELECTRIC signal to the valve/coil. Of course you can't blow through it, and if you energized the injector to get it to open you would likely burn it up by holding it open too long. You may have damaged it, no way to tell till you try to run the motor. You CLEARLY have no spark to CYL 1, if it is wet and you can smell fuel.

I would: Address ECU issue, fix your spark issue
1. Disconnect Battery
2. Locate all power connections and ground to the ECU, including the wiring harness, carefully unplug, check for corrosion, clean where necessary, particularly the grounds, use dielectric grease and reconnect everything. Check Codes & reset.
3. Check spark. Pull plugs from cyl head, plug into wire, lay threads on the cyl head or frame and crank engine, check for spark. If spark isn't healthy (bluish white) or no spark, trouble shoot that coil, plug or wire. That you say you changed the plug caps tells me something may be amis.
4. Once you establish you have spark in BOTH cyls, reconnect everything, double check all the FI connections & vacuum lines, reinstall tank but DONT bolt in place.
5. Try to start the motor and see how things are.
6. If it runs and idles/revs I would let it get warm/hot and CHANGE YOUR OIL - if you have been running/cranking it and have raw gas in your exhaust header, your oil is probably filled or tainted. You could run it and burn it off but...

If you can get it back to an overall good running condition, there are several other things you can check on to cure the pop.

Do you have the Guzzi Diag software and Cables? Best $30 you will spend. You need to have the TB's balanced & TPS/learning parameters reset, probably need to run a couple tanks of Seafoam through the bike too.
 
Allow me to state that this thread started as the stepper motor. I know where I stand there at this point.
Now the bike stopped running while it was running fine with some popping out the exhaust. It appears that the left cylinder is not running and fuel was in the airbox. A lot of it. It only started on the right cylinder and made a strange sound as it quit which may have been nothing more than running on one cylinder. I had just changed the oil pressure sending unit so first thought is lack of oil. Checking for that all looked ok. Next would be if the fuel had been getting in the oil and weakening the rings. The oil level has not changed and doesn't smell so I am guessing no but to be safe I did a leak down test to see if there was anything like blow by past the rings or the inlet valve. Instead I got it past the exhaust valve. While I do not think that is the cause of my current no run situation 27% leak down is way excessive for a 7,400 mile engine so I will get the valves checked. As for blowing air through an injector I was holding in my hand off the bike I was only seeing if something has jammed the injector open. I do not know squat about injection but I'll bet 100 psi of air pressure will do no harm to that injector and if it did go through I would know it was jammed open. Yes it is becoming a comedy of errors but you are telling me to ignore a blatant problem found with the leak down test. I do a leak down test on any engine that is experiencing odd problems as it gives an idea of what is going on in the engine. If one cylinder is that much different than the other that tells me something has been going on.
The bike has had several tanks of Seafoam in it's short life because it had sat and I wanted to clean out any buildup. I have the Guzzitech reflash box and the tps has been reset. I have not checked the balance but I will if it ever runs correctly again. I have no idea if I have a spark issue and unless somebody can tell me I can turn the engine over with the fuel tank off safely I will not know if I do till I get the valves fixed.
If one more person tells me to buy Guzzidiag I am going to scream. As I have stated before. I am not an injection wizard, i tried the Techno Research software and did not like playing with it on my other Guzzi.
Maybe you think I am helter skelter and I am looking everywhere but I did spend 1973-1993 working at a Honda dealer in all capacities, I have a mechanical engineering degree and currently wrench on equipment in a factory so yes, I have turned a few wrenches but will not claim to know it all and I am far from the world's best wrench but I have a clue.
 
To each their own, but I've only done a leak down test if a compression test was inconclusive. And you're right your primary issue right now is that you have no spark at 1 cylinder. Those figures with such a low mileage engine are suspect and I would do a compression test and redo the leak down test.

Changing the oil pressure switch would have no impact on the oil circuit in your motor. It's more than likely you disturb something else while you were doing that.

The fact that you've changed out your plug caps makes that a suspect for no spark. Run down that entire ignition circuit. You also have an ECU error on the dash so checking all of your connections and grounds and ECU make sense. Of course you can crank the engine with the fuel tank removed physically and electrically (fuel pump unplugged). If that triggers the warning light you can reset it. It didn't when I did mine.

Popping from the exhaust can also be something as simple as an exhaust leak. If this is a 2012, has it been rollerized, or still flat tappet? Sun 2012 came with the roller lifters from the factory but there seems to be some uncertainty about when that started.

And don't scream, but if you had Guzzi diag you could also check your engine codes and see real time data from your engine :). You don't need to be or even want to be a wizard to use it. You don't need to use the separate reader or writer programs that up and download Maps. HD is basically just a good tool for communicating with your ECU resetting your TPS and several other tests functions. But, scream or not it's a great cheap tool.

On putting the fuel tank back in, my mechanic showed me a trick. If you look on either side of the tank bolt, there are two small holes in the frame. By inserting two screwdrivers or thin bar into those holes you can then hold them together and leverage the tank forward to drop the bolt in. Made it very easy.

I do hope you get your bike straightened out. no offense intended just trying to help the process along. Seems crazy to me to think about cracking your engine case before you diagnose why you have no spark. This is likely the reason for fuel in your exhaust and intake airbox What other work did you do to the engine?
 
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Rudy,

This is one of those cases where you need to start back at the beginning and forget everything you have already found. It will drive you crazy with all the balls in the air of potential problems. Engineer to Engineer, you need to find the root cause of the issue.

For the popping, I honestly think it is probably related to a loose exhaust gasket, either at the head or along the exhaust. That is usually the #1 and simplest solution, but right now I don't know if that is even related to the fuel flooding.

The ECU error for ECU ground may just be a code cause by the underlying issue and not the root cause. That being said, the ECU has a separate ground, just verify that it is good and move on from that for now.

The fuel in the cylinder and only running on one cylinder. A valve issue would not cause that. That is either an injector issue (which sounds like you have verified as not being the case), a phase sensor issue (not likely since it would cut both cylinders but keep that on the list just in case), the coil, wire, plug cap or plug (all likely suspects in the case).

I would start with the coil, wire, cap or plug. Something is not firing right. There is also and injector relay but pretty sure there is one relay for both injectors so it should be good. Make sure the wire is good and tight at both the plug and coil ends. The plug on my stelvio has a habit of coming loose from the coil and needed a re crimping of the terminal end at the coil and cable tying it in place. Failing all that, swap the left and right coils and see if the problem with the firing on one cylinder follows. You said you replaced the plug caps, what kind did you put in.

Start simple first. The leak down test is a good indication that something is a miss on the left side, but hard to say if they are related to the fuel issue that is your biggest problem. For all you know the leak down test may have been the same if you did it 3 weeks ago. If the fuel did indeed wash the cylinder or lodge something in the valve it is what it is and will need to be fixed, but unless you figure out what the root cause of the fuel and running on one cylinder, it may just happen again when you fix those issues.

As always just my 2 cents. I know you are more than capable of fixing the issue but sometimes we end up going in 10 different directions instead of just looking straight ahead because we want to fix the issue. Start simple, then get complicated if need be.

Joe
 
Let me clarify that I have not a clue if I have spark on both cylinders. I wish I had checked for that initially but I was worried something had come loose and got into the lubrication system as it quit right after I had worked on it. Therefore, go back and check what you did.
On past bikes, when I was even more anal, I would do an annual leak down test to keep track of the condition of the engine. I I know what it is at the start I can track any degradation. I don't do that anymore. As for the suggestion to go back and redo the the test I'll take a leak down test over a compression test any day. When I saw the ridiculous number I turned the engine over a couple revolutions and did it again. What I am thinking of doing is turning it so the exhaust is open and shooting some air in with the hope is is just something that got under the valves.
What is being said it to ignore the 27% leak down and put it all back together and fix the problem. If it was leaking past the rings I would do this on the assumption that the oil had washed off the rings. If I reassemble it and it runs then I know I still have a problem with the valves. I may just do that though to run it a bit and check spark.
I could give a rats ass about the popping at this point but the very first thing I did when it started popping was check all of the exhaust joints and where it bolted to the heads. All were and are tight, The flange bolts I loosened and retorqued to spec.
Fuel in the cylinder is minor compared to "How the heck did it pool in the airbox?" A carb bike I would say the float stuck. As I have stated I really do not think the leak related to the fuel.
My last Norge gave me a bunch of headaches as leaking final drive, rear brake that continually got air in it and others till I sold it because I didn't trust it. Here I sit again but old one had 26,000 miles on it and always made it home. The guy who bought it says I fixed everything as it has been great for him. I don't want to do that again but my trust in this thing is waning fast.
 
For those of you anxiously awaiting the ending of this soap opera with the final answer and who don it, tough. It is a dream (nightmare) sequence apparently. I decided screw it, I'll ride the rest of the season with the leak down if I can get it to run. Pulling a head I am thinking is no big deal. So I put on the tank (except for that @^%#% rear bolt) and instead of setting the plugs on the covers I first put them in and tried to start it. The SOB runs just fine with a bunch of fuel smoke initially from what I am guessing was left in the system as it cleared up after running a bit. Now I need to put the plastic back on and go for another test ride. When it cools I'll do another leak down test to see if something seated. Blowing air through it made no change.
 
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