High Idle Speed - SOLVED AT LAST

Kiwi_Roy wrote:

Tony,
        I will see if I can bring out the end of the stepper hose
It has got worse since I changed out the stepper and I ran some serious dusty road up the Dempster Highway, maybe it's just crud.

You can just block the hose Roy - that stops the stepper doing anything - at least as a first step.

Understand the crud you may be getting, but this is from the clean side of the air filter, so should not get ingress from there. maybe it's just a poor quality stepper, or the aperture within. Who has pulled one apart? What is the actual valve like? Plastic? Metal? Both will wear, both can bind.

Do you use TunerPro Roy? There's a flag to deactivate this alleged "idle map" if you want to try that.

Where is Mark?

Offset 0x481F0

This is in the EEPROM image?

No, main map. I'll deactivate it, and send it to you.

The early valves have a cast metal body with a brass plug commonly called a globe valve, the later one I have now has a plastic body. The plug moves in and out on a fine thread spun by the stepper, a very simple design, it's hard to see them getting stuck.
I disconnected the inlet hose so I can get a feel for how far open it is by the suction, I can also squirt some cleaner into it.
I thought I read somewhere that Guzidiag has an option for stroking the valve, can someone confirm that.

Stroking, instrument speak for operating the valve over its range of travel.

Yes. In the 'Actors' menu.

Ok, I didn't remove the throttle bodies, just the intake hoses sprayed them liberally with carb cleaner.

I plugged the stepper entry hose and it still idles about 1500 to 1900, I'm starting to wonder if there may be an air leak between one of the throttle bodies and the head, is it known for those rubbers to go?

A related question
The RH intake was quite oily, I think it's coming in a hose at the RH of the air box LH was clean
Since this oil cannot get back into the engine, it's just burnt in the RH cylinder wouldn't we be better of to just get rid of it all-together, it's only going to foul up the throttle body.

Also the oil seems to leak out of the air box and make a mess on the starter cover. I may be wrong about that but I couldn't see anywhere else it comes from.
07 2 Valve

Hi Roy; couple thoughts based on my experience getting idle down on 8V. If blocking the air to stepper has no effect then there must already be enough air coming through the air bleed(s) so next step would be to cut the air bleed(s) further (I doubt the inlets are leaking).... If it still idles with both air bleeds shut then either TPS/balance is out or you do have a leak :-).

For the oil, you can't block that pipe as it is the only exit for blow-by gas coming past piston rings/gaps. In theory you could switch to old pre-emissions 'road tube' approach and let the oil/gas to atmosphere or floor but getting it on tyres is danger.

They all look like there is oil coming out the lower seam of the airbox (despite it is closed), I think it is just capillary action letting oil through the bottom of rubber inlet joint with airbox.

Thanks Paul, of course, I should have tried doing a throttle balance again.

Thanks for explaining the vent, When I first got this bike I found a Guzzi mechanic had added an extra spigot to the breather box up at the headstock and ran a rubber hose all the way down past the CARC where it spat out any oil mist, I shortened it to drip out just below the starter, it misses the back wheel.
No, I wouldn't plug the breather but just run it somewhere it doesn't make such a mess, I might try it into a can with some shop cloth to see how much oil we are talking about.

There shouldn't be any vent to atmosphere or need for it.

If you have a hose going to atmosphere reconnect it to the airbox spigot and run your oil lower.

Pete

Thanks Pete. I will plug the additional hose off, it comes from a brass pipe threaded into the breather box.
I'm already running the oil right at the low mark on the stick otherwise I seem to end up with the starter cover saturated

Some info sent to me by Bernd, the author of GuzziDiag. Should be helpful in diagnosing idle issues. I can't verify the efficacy of this test, as I can't walk yet.  

Of course, only one bypass screw should be open.

Show all stepper values in GuzziDiag. There you can see the current position of the stepper.
If it reaches one of the end positions (50 or 200) the stepper is not able to reach the target rpm.
If it is near 200 you have to open the bypass screws.
If it is near 50 you have to close the bypass screws.
If the stepper is near 50 and the bypass screws are closed, then you have a problem ... you have to close the throttle a bit with the 'forbidden' screw.*  


*Do so at your peril. I think that if it comes to this, one should consider rebuilding or replacing the TB's. Charlie J had a TB issue with his 1100 and had his butterflies replaced, and their spindles rebushed. His bike had done 160,000 + kms though.

Hey Mark, rest up and get better.

I will give it another go over the weekend.
Since at the moment I have the stepper inlet plugged off at and it's idling around 1900 I don't think it will work but I may have a bypass screw set wrong. I will start by doing the body alignment again as per Pete's tutorial, just in case I did something wrong, I imagine if it were out by a mile it might idle faster.
The bike has only done 50k kms.
I would describe the idle as harsh, hard to put a finger on it but it just doesn't feel right, makes me want to turn it off at the lights.
It is definitely idling faster than it used to and I swear I haven't touched the forbidden screw but I will examine them closely.

I will unplug the stepper port and take a note of the position.

Probably something stupid I have done.

beetle wrote:

If the stepper is near 50 and the bypass screws are closed, then you have a problem ... you have to close the throttle a bit with the 'forbidden' screw.

Oh no, not the forbidden screw.  Don't you have to bin your carefully calibrated throttle bodies if you mess with the forbidden (or sacred) screw?    

Yep. Hence the 'peril' warning.


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beetle wrote:

Do you use TunerPro Roy? There's a flag to deactivate this alleged "idle map" if you want to try that.

Just noticed this, no. is tuner pro different than Guzzi Diag, as you know I had enough trouble with that.

I can get Guzzi Diag to sort of work but not download capable. PC & Mac too old.

TunerPro is map editing software. What OS are you running? GuzziDiag doesn't require much.

OK I spent some time on the bike.
First of all I checked the throttle balance using the Roper method
Both air bleeds closed.
The high speed balance was just a little out < 2 inches of oil in the manometer, adjusted the crank screw < 1//2 turn
Low speed balance was about 8" out, opened the air bleed ~1/2 turn.

Connected Guzzidiag laptop, finally figured that I had to go File/Connect
Before I started
RPM 0, CO Trim 0, Stepper Controller 64. Throttle 4.5

Started
RPM 2466
Stepper Break 162, Stepper Base 100, Controller 0

The RPM would drop to 2100 if I blocked the stepper inlet hose with finger.

Later I started the bike up it was running about 1500
I was watching Guzzidiag Stepper controller it was sitting at 58 or 60 not sure but all of a sudden it dropped to zero at the same time the revs shot up to 2500+


My Guzzidiag keeps crashing
V0.47 running on a Mac OS X 10.5.8
I can't find a menu for setting the TPS, where is that?

Thanks in advance
Roy

Actors, Roy, it's in there!

In the Actors menu. Use one of the drop-downs.

Mark, just know I really appreciate your help, I'm at a loss to know what has gone wrong with the old girl, it was running so well earlier this year, I'm trying to remember everything I saw

I did pull down the drop down and open actors
VIEW/
Measurements
Diagram
Faults
Actors
CO Trim

ACTORS/
Fuel Pump
Ignition Left
Ignition Right
Stepper Idle Control   I think the option was Start/Stop (I was looking for a button that said Set or Reset)
I did toggle the one I saw there

Fuel Pump seems to work without the bike running, at least I can hear something that sounds like the pump, ignition Left and right also sounds the same, they do nothing while running
So I assume Stepper Idle Control only works while key is On but not not running also.

Getting back to the fast idle, at one time the bike seemed to be idling ok at 1500 I think Idle Stepper Controller was reading 64 or 58, it switched to 0, no ramp down and the idle went right away to 2500 or so, throttle reading didn't move from 4.50, it will slow down a little if I plug the stepper intake but only to about 2000, usually when I started it it went straight to high speed, it doesn't seem to follow a pattern.
Thinking about this some more perhaps the sudden drop of the Stepper Controller to zero was the response to the increase in revs, not the cause of it.


Its hard to imagine how the revs can jump up with no increase in throttle opening, I don't touch the throttle and it can jump 1000 revs.
I can see the stepper doing that but not if I have the inlet blocked.

It's very unpleasant to ride this way, have to keep the brake on in slow traffic.
I loosened off the intake rubbers and slid them around no sign of a crack
I inspected the linkage and idle grub screw, all the yellow paint is still intact
I did let the bike heat up and clicked on CO Trim, I only saw it at 0, I wasn't sure what I was supposed to be doing there

It doesn't help that I cannot get on the net where I work on the bike.

I thought I saw a new thread on using GuzziDiag, it's hard to follow the 48 page version on Wild Guzzi

I have a PDF version. Download link:

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Thanks Mark
The instructions make it clear.