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Iron Butt
Posts: 802
| Hi Guys,
When I'm slowing down in gear with the throttle closed and pass 1750 rpm or thereabouts the engine surges as the ECM turns the fuel back on. The surge is pretty strong and can be a pain particularly when going around a slow corner. Do you notice the same thing and does anyone know of anyway to soften it up? I'm running a PCV and Autotune with Lloydz cams and aftermarket air cleaners.
Thanks,
Marc |
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Puddle Jumper
Posts: 48
Simpsonville, SC | I have a stock 09 vision that does the same thing, it is annoying, I assume it it to prevent popping on decel. |
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Puddle Jumper
Posts: 48
Simpsonville, SC | Also, I would have thought you could program that out with the PCV or VFC III. |
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Iron Butt
Posts: 802
| gcefalo - 2011-01-18 2:49 AM
Also, I would have thought you could program that out with the PCV or VFC III.
I emailed Jamie at Fuelmoto yesterday to see if he has any suggestions as to PCV settings. Haven't heard yet.
Marc |
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Cruiser
Posts: 111
Prairie Dog Heaven, CO | Marc,
is this most prevalent when you come back down from a tour to higher altitudes? My bike is stock and I have this problem when I descend from a trip to the mountains (which is pretty much every ride here in CO). In these cases, the bike will also surge badly around 1700 rpm and it will idle at 1500 rpm. Turning the ignition off for a few seconds and starting back up always cures that - and the surging. Must have something to do with the fueling adjusting to lower ambient pressure and then not adjusting back. Does not make sense to me and I have never heard a reasonable explanation for it so I just turn the bike off and restart at the first opportunity after returning to the plains.
Frank
Edited by picard 2011-01-18 12:32 PM
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Iron Butt
Posts: 802
| No, it doesn't relate to altitude. It does it all the time. The FI system has a fuel cutoff on decel (closed throttle) which turns the fuel back on again at 1750 rpm at which point it bucks. I've tried playing with the fuel mixture at the transition point at 0 throttle to no advantage. I also just tried retarding the timing from 2000 to 1250 rpm by 5 degrees to try and soften up the hit but that isn't helping much either.
Marc |
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Visionary
Posts: 4278
| You guys need KevinX he can tell you why and if there is a fix he can tell you |
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Visionary
Posts: 3006
San Antonio, TX | I use the engine as a brake all the time and use two ways to get around the issue.
1. Leave the throttle a little open. Do not let it roll all the way closed!
2. Around 1800 rpm I pull in the clutch and start to feather it out at 1550 rpm.
Give these and try and let me know your results.
Ride Safe |
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Iron Butt
Posts: 802
| radioteacher - 2011-01-18 12:07 PM
I use the engine as a brake all the time and use two ways to get around the issue.
1. Leave the throttle a little open. Do not let it roll all the way closed!
2. Around 1800 rpm I pull in the clutch and start to feather it out at 1550 rpm.
These steps will undoubtedly work since you aren't allowing the engine to hit the 1750 rpm switch point under any load. I was trying to actually get rid of it or at least minimize it. So far I've retarded the ignition 5 degrees and increased the fuel by 20% at closed throttle between 2000 and 1250 rpm. It helped a bit but there's the distinct possibility that I won't be able to get it any better. I guess I'll just go back to pulling the clutch in sooner like you do. I was speaking with Greg Benner who has the same setup I do and his barely does it. Just goes to show how similar bikes can be different.
Marc |
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Puddle Jumper
Posts: 44
Middleburg, Fl. | Mine does it - stock 2011. Would love to get rid of it! |
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Cruiser
Posts: 60
Vancouver, B.C. & La Quinta, CA | I experience the very same thing. Even stock it burped at about 1700 rpm. After a few motor mods, same thing. Installed a PCV, it helped by about 50%. I am going to work with the PCV to try and eliminate it. My dealer says; "they all dot, there is no fix". That seems silly to me. There must be a fix and I believe it is is in the fuel controller. So far I am 50% correct. Time will tell however. Clutching and feeding throttle at the precise moment will alleviate this, but who wants to patch a problem when able to eliminate (hopefully). Keep us posted and I'll do the same.
Cheers |
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Iron Butt
Posts: 802
| DAL - 2011-01-18 10:34 PM
I experience the very same thing. Even stock it burped at about 1700 rpm. After a few motor mods, same thing. Installed a PCV, it helped by about 50%. I am going to work with the PCV to try and eliminate it. My dealer says; "they all dot, there is no fix". That seems silly to me. There must be a fix and I believe it is is in the fuel controller. So far I am 50% correct. Time will tell however. Clutching and feeding throttle at the precise moment will alleviate this, but who wants to patch a problem when able to eliminate (hopefully). Keep us posted and I'll do the same.
Cheers
Here are some observations and things to try with the PCV:
If you're running Autotune make sure that the 0 throttle column has all 0's in it. If Autotune sees a 0 it won't monitor that position so you can set it using the PCV tables and it won't change. That column is normally 0 anyway.
The fuel cutoff switch from what I can figure out completely shuts the fuel off so any mods you make to the PCV fuel tables at 0 throttle above the switch point rpm will do nothing. That also applies to the ignition table.
From observation it seems that the switch turns back on again at 1750 rpm.
On the fuel tables (cyl 1 & 2) I used a block from 2000 to 1250 rpm at 0 throttle to make my adjustments. That way we're sure to catch the transition. You will probably find all 0's in the 0 throttle column which means the PCV isn't doing anything at that point. I tried leaning it out by -15 in that 2000 to 1250 block but it didn't help. I then tried richening it up by 15 and then went to 20 which seemed to help. Often a fat mixture will reduce rpm by a little bit. Conversely leaning a mixture will often cause rpm to rise so it makes sense that richening it would help a little bit.
I then tried playing with the ignition timing table. I retarded that same block between 2000 and 1250 at 0 throttle by -5 degrees and then tried it again at -10 degrees. The -5 seemed to be the most effective. This has the effect of reducing power slightly which should soften the effect.
Overall the changes seemed to make a little difference but certainly nothing to get excited about. One interesting thing is that some bikes buck more than others. Greg's CC which has the same setup as mine barely bucks at all. I don't know what the difference is beyond manufacturing tolerances. I've been thinking about the TPS and if there is a way to fool the ECM so it doesn't know when the throttle is closed. Probably a bad idea. Another thing I found out about yesterday is that Harley uses the same fuel shutoff scenario. One of the aftermarket fuelers available for their system has the ability to disable the switch in the OE software. Once turned off the fueler can tune the 0 column and eliminate the transition altogether. We don't have any such luck. If you come up with anything please let us know.
Marc |
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Cruiser
Posts: 62
ESCALON CA. | I ALWAYS ASSUMED IT WAS THE IDLE AIR CONTROL VALVE TURNING BACK ON & THAT THE LLOYDS VALVE WOULD PROBABLY HELP, BUT HAVEN'T TRIED IT YET. MAYBE E-MAIL LLOYDS. |
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Iron Butt
Posts: 802
| After riding around some today I decided that the changes to the PCV that I made really weren't helping that much so I put them all back to 0.
Marc |
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Iron Butt
Posts: 612
| It is my understanding that on Victory motorcycles, the Power Commander ignition tables have no effect. |
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Visionary
Posts: 4278
| I'm wondering if any of you has called PC and ask them or if you have check for a air leak or maybe a bad wire if you have tried a new idle air control valve.
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Iron Butt
Posts: 802
| Turk - 2011-01-21 6:53 AM
It is my understanding that on Victory motorcycles, the Power Commander ignition tables have no effect.I just checked with PC and they say it works but only to use the ignition mod over 2500 rpm due to Vic's built in double spark below that rpm. I'm not sure what he was referring to.
Marc |
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Iron Butt
Posts: 802
| john frey - 2011-01-21 9:28 AM
I'm wondering if any of you has called PC and ask them or if you have check for a air leak or maybe a bad wire if you have tried a new idle air control valve.
I have a new valve in my hand as we speak.
Marc |
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Iron Butt
Posts: 742
North Orange County CA | Great!
I've been able to ignore or work around this "feature" for almost three years and have enjoyed the hell out of my Vision. Now, thanks to reading this thread , every time I close the throttle I notice the surge; and for some inexplicable reason it seems to be getting worse.
It's like having a bad tune stuck in your head that just wont go away!
MAMBO #5 Right back at ya! 
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Iron Butt
Posts: 802
| Tarpits99 - 2011-01-21 10:02 AM
It's like having a bad tune stuck in your head that just wont go away!
I know exactly what you mean. BTW, the idle control valve did nothing.
Marc |
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Iron Butt
Posts: 802
| I spoke with Lloyd today and he had some interesting insight to the transition problem and also to changes that Vic made to the '11 bikes which have taken care of the pop on decel and stalling issues the earlier bikes had. He said that his Idle Air Valve should make a big difference in the transition so I ordered one. I'll report back when I get to try it out.
Marc |
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Cruiser
Posts: 60
Vancouver, B.C. & La Quinta, CA | Got rid of the decel problem with some fine tuning of the PCV. I am not using the auto tuner. Happy now! |
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Iron Butt
Posts: 742
North Orange County CA | So.............., any updates?
Have any of you guys resolved this issue without spending $1000s on upgrades?
Are Cams, Upgraded ECU, PCV, intake plate, Etc. the only path or will the IAC do it by itself?
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Tourer
Posts: 500
| I have an 2011 Vision with S1L1 from dealer, otherwise stock...I have not noticed any of the above issues with bike so far...My 08 Kingpin with Stage 1 kit used to "pop and crack and backfire" all the time..Do not miss it on the Vision...2400 miles so far..Is this something that happens down the road or has it been corrected as some have said....... |
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Iron Butt
Posts: 802
| I have all the upgrades you've mentioned and it is still there. Lloyd's IAC helped a little bit. Otherwise I've gone to clutching through the transition whenever possible.
Marc |
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Surge on Decel at 1750 rpm
