Guzzidiag query (merged)

[Huzo]

Can someone tell me what the Idle Stepper Base reading refers to ?

[tris]

I thought that some better informed than me would have popped up by now H

I think that it's a baseline remembered by the ECU that the stepper starts to count from and is set by the initial physical jerks set by the bike at start-up.

However, I'm happy to be corrected if that is incorrect

[Huzo]

Hmmm.
My Norge has started idling too high, around 1800 rpm, then sort of settles….Sort of.
I have checked the stepper motor and it cycles when I switch the key on and off. I might have picked up an air leak somewhere…Dunno.

[tris]

 If a bit of crud has got in there it could hold the valve open a tad and the ECU would see that as the base line which could cause it to be lean as it would start from the slightly open position

A coat of cleaning might help and IIRC you can make GD stroke the valve, but its a long while since I've messed with a CARC bike.

[Huzo]

Mmmm.
As you see it’s currently at 100.
What the hell does that even mean ?

[SemperVee]

  I don't know of ANY FI engine that does not idle higher when first started then settles down.  This includes my 2022 Ford F150,  My 2012 Victory  and my 2007 MG Norge.  As long as it comes back to 900-1100 idle after a minute you are  good.

[tris]

Mmmm.
As you see it’s currently at 100.
What the hell does that even mean ?

I Don't think that it  means anything,  it's just a number to start with

Your description seems to suggest a sticky valve to me, and if you're asking nout the Norge I'd guess that it's a new feature

Bloody expensive new, so hopefully a clean will sort it out .

[Huzo]

  I don't know of ANY FI engine that does not idle higher when first started then settles down.  This includes my 2022 Ford F150,  My 2012 Victory  and my 2007 MG Norge.  As long as it comes back to 900-1100 idle after a minute you are  good.

This happened when I got back from picking it up from the depot in Melbourne. I have had the tank off and airbox out, so I took the stepper off and gave it a spray internally (as much as one can). I’ve had this bike a long time and know it well, I’m just glad it happened here and not in Europe.
I still have to properly fix the wiring issue that occurred in Europe, but I cannot see how that is relevant.

But anyway…Onwards and upwards..!

[tris]

Just had a thought.
Can you reach under the tank with some long forcepts and grab the air feed line  to the valve and choke it off?

If you can and the idle drops that would indicate a faulty valve.

Also GD has a stepper test IIRC revs should change when you push it

[Huzo]

Just had a thought.
Can you reach under the tank with some long forcepts and grab the air feed line  to the valve and choke it off?

If you can and the idle drops that would indicate a faulty valve.

Also GD has a stepper test IIRC revs should change when you push it

That is a good diagnostic ploy Tris, I did not think of it and will pursue it.
Thanks.
What I’ll do is pull the vacuum line off and plug it, then throw the tank back on and check it out. Funny thing is, I could never get a nice idle with the gears installed in the timing chest.

I’m doing a FULL service (200,000 k) so there are dozens of things on the go, the bike is in a hundred bits at the moment, but good fun..
I needed a new gasket for the timing cover and could not get one, but good old Roper came to the rescue..
A rock of Gibraltar if ever there was.

[tris]

Good luck matey

These valves are a POS. I had 2 at one point and both if driven shut with a little circuit I conjured up one side would leak.

[HarveyMushman]

How many miles? Worn TB's will give you a high idle. 

[Huzo]

How many miles? Worn TB's will give you a high idle.

Yeah 208,000 km (128,000 miles).
Thing is, I stopped to say hi to a mate on the way home after picking up the bike and it started and idled normally.
Then 15 minutes later at home as I pulled in, the idle sat at 1800…
Not the biggest drama I guess.
The suggestion was to crimp the air feed to the stepper to see if that dropped the rpm, if it did then it’s a faulty stepper.
I think I’ll follow that course, but instead just take the airbox cover off and plug the hole from in there.

[Huzo]

A picture’s worth a thousand words, so here it is…
https://youtu.be/OMCbqZI58Ps
BTW…
Those gears are for sale, there is NOTHING wrong with them, I’m just staying with the chain…

[Tom H]

FWIW: I was working on a Stevlio that had a bit of a rough idle and it would idle at about 1500. After much reading, it was fine to idle there or could try cleaning the stepper motor.

For the Stelvio, you just had to pull the battery and it's mounting case, no messing with the air box. The stepper hose was then easy to get to. Sprayed some TB cleaner in the hose and let it sit a few minutes. Repeat then turn the key on and listen for the stepper. Repeat a few times to cycle it. Spray more cleaner and then start the bike. With luck that should do the trick. worked for me. Idle now at 1100 to 1200 as it should be.

Good luck!
Tom

[guzzisteve]

Just for kicks I looked up a new one, GASP   $814.00 USD In 2009 they were $100. 

It's not even needed if you put a manual valve in the hose, like a $15 inline fuel tap.

[Huzo]

Just for kicks I looked up a new one, GASP   $814.00 USD In 2009 they were $100. 

It's not even needed if you put a manual valve in the hose, like a $15 inline fuel tap.

I will start by blocking it off inside the airbox to see if that’s the cause.

[Tom H]

I tried pinching the hose with pliers, the first time it seemed to make a change. The second time it made no difference in the high idle. Just sayin'

Tom

[tris]

Just for kicks I looked up a new one, GASP   $814.00 USD In 2009 they were $100. 

It's not even needed if you put a manual valve in the hose, like a $15 inline fuel tap.

It's a standard Ducati part, but availability might be better on the Ducatis.
Interestingly Ducati changed the design on later bikes, so they obviously sussed that it was a pants design. Sadly I don't believe that they're interchangeable

[Huzo]

I did what Tris suggested and blocked the air supply to the stepper.
I did it inside the air box and the idle immediately dropped to 1000 rpm but a bit erratic.
So it’s the stepper.
I’ll see if it settles, because it could still be an erroneous command from a sensor.

[tris]

That's progress.
IIRC it was Kevin in NZ who did some work and proved that blocking the air feed dropped the idle speed to 1k.
The reason it's lumpy is probably because the TB bypasses are now wrong because you have been tuning out the leak.

Worth having a go at cleaning it though

[Huzo]

Okay here’s the latest.
There are a few functions on GD that I don’t know how to drive. I successfully got the TPS reset done along with self learning parameter reset so that’s ok. The TPS value is sitting around 4.7 which is what Beetle says is the go.
At one point, I was looking at the TPS reading and it fluctuated around without any intervention by me, but it’s settled at 4.7 so on we go.
After reading over Beetle’s tutorial again on CO trim procedure, I thought that my fast idle might be a function of that being arse up….
It was on +1 so I ratcheted it in both directions quite a way, but there seemed to be no real change. It’s currently at -10 which is within decent limits according to Beetle.
But it’s still not dropping down to a steady 1150 idle.
Now I see there’s this function on GD


With this showing up on the readout


What conclusions should I be drawing and is there something I should be doing ?
Just for general interest, at one point the engine was idling at (more or less) 1,300 rpm then with no intervention by me, dropped SUDDENLY down to 900 rpm then caught and just as suddenly jumped back up to 1200 or so.
Is this an erratic stepper ?
There are no apparent air leaks in the intake tract.
Interestingly enough, I cleared away some stored faults and ran it up again, there were no actual faults recorded.

[tris]

It might be a faulty TPS.
GD has a graph feature.  Get it to trace TPS, and slowly and steadily open the throttle to WOT and see if you get any random jumps.

[Huzo]

It might be a faulty TPS.
GD has a graph feature.  Get it to trace TPS, and slowly and steadily open the throttle to WOT and see if you get any random jumps.

I’ll do that tomorrow Tris.
Also I have this spare stepper.




The one with the white text on it is the non original spare. It can be seen that the two number sets on each one are different.
Does anyone know what significance these numbers hold ?
Also I don’t know what this does

[Huzo]

This is what it did this morning.




Can I ask, what is the potentiometer rear throttle position code telling me ?

[Huzo]

Short and sweet.
What is the best method for cleaning throttle bodies on the Norge ?
I am happy to remove them.

[Bisbonian]

When I did this on my 1200 Sport I just removed the throttle bodies as a set and used spray carb cleaner on them.

[sdcr]

When I did this on my 1200 Sport I just removed the throttle bodies as a set and used spray carb cleaner on them.

IIRC, the last time I cleaned one, I was advised to use a specific Throttle body cleaner. Something about damage to the inside coating of the TB could occur if standard carb spray used.

[Dirk_S]

I’ve also read there’s a distinct difference between the two cleaners.

[bigbikerrick]

Its best to use the spray made specifically for TBs. Regular carb cleaner may be too harsh for some of the components. I have carefully used some gasoline, and a little brush to clean them when thats all I had on hand. I figgured, they are exposed to gas anyway, so it could not hurt anything.
Rick.