Rocket III stumble at slight throttle

concours

concours

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2014 R3T, 2.3 liter, It's been doing it for a few hundred miles now, getting worse. About 1500-2000 rpm, with very light throttle in the lower gears. Not there with a cold engine, gets worse hot.
Keihin engine management system, I have "hot" tune I put in with TUNEECU. (Which has worked PERFECTLY for 7 years, 20,000 miles, dispatching all comers)
I have a fuel pressure gage coming. I had to check valve clearances to rule out a tight valve.
My TUNEECU software is currently inop, the Windows version is no longer supported, waiting for an Android device to be delivered so I can run it, check more sensors, devices.
If it were a carbureted engine it would feel "too lean/weak" just off idle.
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Hmmm, i've had something similar as you describe, but on a 2013 T100 Bonneville. Not a misfire, but a subtle power dip every second or so while at steady cruising speed or even accelerating. All gears, all rpm. Goes away if coasting in neutral or clutch in. Had this for years. Now at 70k KM's and it feels more noticeable than ever.
Tried all kinds of things: balancing throttles via TuneECU, re-mapping with several different maps, two from a professional outfit, new plugs/caps/leads/coil, adjusting crank position sensor gap, throttle position sensor adjusted, disabling O2 sensors, replaced fuel filter in tank. Recently checked compression, good at 150psi each can.
Have not pulled injectors to check/clean spray patterns.


Never found anything that affects the issue.

BTW I think TuneECU does still work, but must be used on older versions of Windows OS, not updated for newer OS. I have two older laptops running Win7 and it works fine.
 
If it's OK on cold warm up that's because the cold map overlaps the main map and its getting extra fuel ,when its warmed up it will be just on the main fuel map , can you adjust accel sensitivity? . Or save the whole tune then, rename a nother tune and bump a few cells up in the light load / rpm area you are having issues with . Dont forget basic stuff like vacuum leaks etc Cheers ,
 
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Tornado said:
Hmmm, i've had something similar as you describe, but on a 2013 T100 Bonneville. Not a misfire, but a subtle power dip every second or so while at steady cruising speed or even accelerating. All gears, all rpm. Goes away if coasting in neutral or clutch in. Had this for years. Now at 70k KM's and it feels more noticeable than ever.
Tried all kinds of things: balancing throttles via TuneECU, re-mapping with several different maps, two from a professional outfit, new plugs/caps/leads/coil, adjusting crank position sensor gap, throttle position sensor adjusted, disabling O2 sensors, replaced fuel filter in tank. Recently checked compression, good at 150psi each can.
Have not pulled injectors to check/clean spray patterns.


Never found anything that affects the issue.

BTW I think TuneECU does still work, but must be used on older versions of Windows OS, not updated for newer OS. I have two older laptops running Win7 and it works fine.
Click to expand...
This stumble is severe now, helmet banging when riding two up.
I have 2.5.8 on my Windows 10 laptop I've always used, and now it won't work. (Can't open the comms to ECU) I tried loading 2.5.5, but the zip file won't extract. Pretty sure the creator changed his mind about the "free" part, and wants some payment now.
6FAF3686-481E-4801-B331-F6AF426BE78C.jpeg
 
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Shelby-Right said:
If it's OK on cold warm up that's because the cold map overlaps the main map and its getting extra fuel ,when its warmed up it will be just on the main fuel map , can you adjust accel sensitivity? . Or save the whole tune then, rename a nother tune and bump a few cells up in the light load / rpm area you are having issues with . Dont forget basic stuff like vacuum leaks etc Cheers ,
Click to expand...
Agreed. Thank you.
I was trying to figure out what has degraded to cause a tune that worked well, to now be acting like that.

I noticed when I first put the tune in, the low end was LEANER than stock.... I wrote the idea off to not needing to keep the cats lit.
So, yes, that will probably be the end game.
 
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concours said:
This stumble is severe now, helmet banging when riding two up.
I have 2.5.8 on my Windows 10 laptop I've always used, and now it won't work. (Can't open the comms to ECU) I tried loading 2.5.5, but the zip file won't extract. Pretty sure the creator changed his mind about the "free" part, and wants some payment now. View attachment 105878
Click to expand...
If the program launches and runs fine, just won't connect to the ecu, then I suspect the usb port driver has updated to one that doesn't play well with your cable. I recall there was guidance on Trat about not letting Windows search for latest driver on-line when first plugging in the cable and to select one of the default ones already on the pc. You might need to disconnect cable from pc, go into your drivers lists and disable/remove the one in use for the cable, then reconnect and stop the auto search for latest drivers on line.
 
Tornado said:
If the program launches and runs fine, just won't connect to the ecu, then I suspect the usb port driver has updated to one that doesn't play well with your cable. I recall there was guidance on Trat about not letting Windows search for latest driver on-line when first plugging in the cable and to select one of the default ones already on the pc. You might need to disconnect cable from pc, go into your drivers lists and disable/remove the one in use for the cable, then reconnect and stop the auto search for latest drivers on line.
Click to expand...
I'll give it a try. Thank you.
 
Tornado said:
If the program launches and runs fine, just won't connect to the ecu, then I suspect the usb port driver has updated to one that doesn't play well with your cable. I recall there was guidance on Trat about not letting Windows search for latest driver on-line when first plugging in the cable and to select one of the default ones already on the pc. You might need to disconnect cable from pc, go into your drivers lists and disable/remove the one in use for the cable, then reconnect and stop the auto search for latest drivers on line.
Click to expand...
Can you use another laptop or older windows version and or try different coms cable ? On some ecus you can select different coms ports .
 
Last edited:
Shelby-Right said:
Can you use another laptop or older windows version and or try different coms cable ? On some ecus you can select different coms ports .
Click to expand...
I had two "generic" OBD-USB cables, neither worked, and they always did.
I DID connect with a generic auto OBD scan tool, cleared a code (one I intentionally created), no problem. No older laptops here, my work PC nerds have that one all locked down, can't install any programs. Wifey is an apple Koo-Aid addict.
Today's challenge, (in & around driving 200 miles & working) to find two valve shims. My two local dealers closed up when Triumph hired the Harley marketing guy. 🤡
The big Boston area shop, I've been trading there since 1975, gave me punk attitude when I asked for Triumph valve shims ( I had part numbers).
"Anything Triumph, we're not gonna have, have to order it."
After I mustered all my patience, to explain to the little turd how 25mm valve shims fit a plethora of Yam/Honda bikes (they also sell/service BOTH of those brands there!), he begrudgingly looked them up. Nope. No gots.
We're fucked.
 
concours said:
2014 R3T, 2.3 liter, It's been doing it for a few hundred miles now, getting worse. About 1500-2000 rpm, with very light throttle in the lower gears. Not there with a cold engine, gets worse hot.
Keihin engine management system, I have "hot" tune I put in with TUNEECU. (Which has worked PERFECTLY for 7 years, 20,000 miles, dispatching all comers)
I have a fuel pressure gage coming. I had to check valve clearances to rule out a tight valve.
My TUNEECU software is currently inop, the Windows version is no longer supported, waiting for an Android device to be delivered so I can run it, check more sensors, devices.
If it were a carbureted engine it would feel "too lean/weak" just off idle. View attachment 105870View attachment 105871View attachment 105872
Click to expand...


Bob,

Does your bike have a TPS? Sometimes they develop a worn spot (usually in the area right off of idle) that will test out well, but stil cause a problem. Sometimes they can be re-adjusted to a different value to check for a change in performace/test. Other times you have to bite the bullet and just get a new one if you suspect that it is the issue.
Pete
 

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