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Bad Idle, where to start?


Jacob Ezzell

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My pretty new-to-me 2000 V-11 Sport has developed a habit of chugging to a halt at idle, like when sitting at a stoplight. Not all the time, I feel like it's more likely to happen when hot, but not always. Sometime soon I'm going to pull the plugs and check them out, maybe replace them just for kicks, but if they are fouled then something else must be wrong. I have a powercommander but I don't know how it's mapped.

 

Should I just bite the bullet and take it to the local guzzi/ducati/triumph shop and have it tuned up? It came to me from a much lower elevation, so I'm not sure if that's what made the difference.

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Personally, I'd ditch the power commander (temporarily) and revert back to factory settings for CO, TPS, valve clearance etc and balance throttle bodies. That should make allowances for any difference caused by the change in elevation and if nothing else, give you a known baseline to start a proper diagnosis. Chances are it's something silly and power commanders have been known to cause problems if not set up correctly. Once you've got it running sweet, refit the PC and git it set on a dyno. Trust me, it makes all the difference.

 

Good lucj with it.

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I'd check the valve clearings first. Set them to .15mm/.20mm in/out or both at .22 if you want. Especially the intake valve should not be tighter than .15.

As long as that's the only problem I def. would not bother with synhronisation, TPS and whatever more technical fantasy might bring up.

This can help as well, especially when the unit was tuned for a completely different height elevation (thx).

 

hubert

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I'd check the valve clearings first. Set them to .15mm/.20mm in/out or both at .22 if you want. Especially the intake valve should not be tighter than .15.

As long as that's the only problem I def. would not bother with synhronisation, TPS and whatever more technical fantasy might bring up.

This can help as well, especially when the unit was tuned for a completely different height elevation (thx).

 

hubert

 

Hi

 

Bad idling is likely to be roughly in order of likelihood and ease of diagnosis:

1. leaks in the throttle body rubbers

2. very out of balance throttle bodies

3. TPS setting too lean ie

4. TPS fault eg open circuit

5. very very badly adjusted PC

6. throttle body spindle seal leaking on 50K miler bikes

7. pressure regulator starting to fail (v rare)

 

A list created from much experience. Common denominator except point 2 is all give a lean setting. Another clue is jerky hunting on a light trailing throttle or hunting at a steady speed. Bike runs quite hot so unless it is really really lean you don't get much of a clue from the plugs. Likewise 60%+ throttle openings see the bike running perfectly. The reason why it shows when hot is that the startup mixture is very rich on the standard ECU setting, and stays so for at least 15 miles. This compensates for the otherwise lean setting so for the first few miles the bike runs fine.

 

Cheers

 

Guzz

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When I had a problem with my bike "flaming out" as in stalling when pulling up to a stop sign, I fixed it by adjusting the valve lash then sychronzing the throttle bodies and resetting the TPS. If you don't want to get into a full tuneup yet I think the first thing that you should do is set you idle to 1050-1100rpm if it isn't already there. Use only the throttle stop screw on the left side throttle body to do this. The next thing to look at is valve lash. Most here set it to .006" intake and .008 exhaust instead of using the specs in the manual.

 

It's really easy to adjust the valve lash on these bikes if you don't mind taking the time to learn. If you dig around this site you'll find instructions on how to do that or the complete tuneup yourself. For the complete tuneup I prefer the Micha method which is simple and effective. If you have a question or run into a problem you can always post it here. Of course if you'd rather not muck with it there's nothing wrong with bringing it to a shop.

 

Good luck!

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My 2001 V11 Sport has a simiar problem, will idle nicely fo about a minute then miss a beat and die, I thought it was a sloppy timing chain so I borrowed a strobe light last weekend, I couldn't see any timing marks but I found the right cylinder misses a spark now and then.

Same thing happens with the stock ECU

 

Elevation change should be compensated by the pressure sensor in the ECU.

 

Everyone says idle at 1100 but if I do that the engine braking is next to useless, besides it should idle slower.

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.. Elevation change should be compensated by the pressure sensor in the ECU...

 

Right, but the PC above it does not so. So any faults here become multiplied instead of compensated.

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My 2001 V11 Sport has a simiar problem, will idle nicely fo about a minute then miss a beat and die, I thought it was a sloppy timing chain so I borrowed a strobe light last weekend, I couldn't see any timing marks but I found the right cylinder misses a spark now and then.

Same thing happens with the stock ECU

 

Elevation change should be compensated by the pressure sensor in the ECU.

 

Everyone says idle at 1100 but if I do that the engine braking is next to useless, besides it should idle slower.

 

By most accounts I think 1100 is pretty spot on for idle. I think the two biggest reasons are oil pressure at idle and the other (according to a few of the gurus around here, not me) is that a low idle is harder on the splines and whatnot rattling around in there. If you're losing engine braking maybe this indicates an air leak somewhere? :huh2: Mine is set right around 1100 and I don't have that particular problem. That said, I have no reason to believe that what works for one V11 should in any way work for the next, if experience means anything.

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... set you idle to 1050-1100rpm if it isn't already there. Use only the throttle stop screw on the left side throttle body to do this.

 

Is this the tiny allen screw on the back side of the left throttle body? None of my shop manuals clearly identify this one, but they do say that there is a 2nd screw that should never be used to set idle. :huh2:

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... set you idle to 1050-1100rpm if it isn't already there. Use only the throttle stop screw on the left side throttle body to do this.

 

Is this the tiny allen screw on the back side of the left throttle body? None of my shop manuals clearly identify this one, but they do say that there is a 2nd screw that should never be used to set idle. :huh2:

 

Yes it's a small allen screw that probably has yellow glyptol or paint on it. Twist the throttle while watching the left side throttle body and you should be able to see which screw is the throttle stop. Don't touch the big white knob, that controls the sychronization between throttle bodies. You can use the left side throttle stop screw to turn the idle up a little but if you try and turn the idle down you need to use the stop screws on both throttle bodies. You might need to dig the glyptol out of the allen screw head with a pin.

 

Many here including me back the right side throttle stop screw off so it doesn't stop the right side throttle because there is slop in the ball joint that's part of the throttle linkage. Backing the right side stop screw off lets the spring on the right side TB take the slop out of the throttle linkage so both throttle plates move in unison when coming off their idle position. Some use a feeler gauge to set the right side throttle stop screw very close to the throttle plate once the idle is set, other just remove it altogether.

 

I hope that made sense...

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I posted that I was having a stalling issue also. Finally I got around to connecting a strobe (timing light) and I found that every so often it missed a spark on the right hand cylinder. I couldn't figure out why it should do that. I reset the position pickup which is supposed to be 0.7 - 0.9 mm, this had no effect.

I thought perhaps the coil may have a problem. on checking I found 2 of the 3 rubber shock mounts broken and no direct path to ground for the coils. The spark is probably going to ground back through the primary connections so I added a ground wire from coil frame to the chassis.

Although it's still not perfect the stalling is almost cured.

Check your coils out, see if a ground helps at all.

Cheers

Roy

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Not sure I understand.

The two coils have a common connection that is connected to +12V via the fuel pump relay. The other side of the coils go to the ECU which grounds the coils via its power transistors.

 

Are you talking about ground the ECU case?

Are you grounding the coil body ( perhaps increasing the electrical shielding )

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Not sure I understand.

The two coils have a common connection that is connected to +12V via the fuel pump relay. The other side of the coils go to the ECU which grounds the coils via its power transistors.

 

Are you talking about ground the ECU case?

Are you grounding the coil body ( perhaps increasing the electrical shielding )

Cliff,

I realize the coils are grounded thru the battery, I should have measured to see if the secondary is connected to primary or the coils frame. I just figured perhaps the spark was somehow injecting back into the ECU and messing with the count somehow.

The stock ECU has the same symptoms as MyECU so I know it's not that otherwise I would have posted on your forumn.

Yes the ECU is well grounded.

I do have my idle set slower than most ~1000, at what point does the ECU think the motor has stopped?

Which spark occurs first after the missing tooth, left or right (sitting on bike)?

I will try switching the coils over, see if the symptoms move.

Perhaps I disturbed a bad contact but it's definately idling better with a ground to the coil frame.

It never misses a beat off idle, I would expect a bad coil to act up more at WOT

Cheers

Roy

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