Motor surging

[1K9]

Disconnect the linkage then plug the stepper back in. The ECU will see it is there and turn the light off. But it will not function because the linkage is disconnected/gone.

TBs have 2 sets of butterflies, one set at top that @Claviger removed and the primaries at the bottom that control air/gas

Ill try to reach it without taking the bodies off.

 

[Scholle]

In my mind, the butterflies normally are fully closed at sero throttle, when the bike is running, just to increase the motor brake effect. The butterflies will open slightly, when the engine is at idle to keep the engine running. This will be managed by the idle stepper motor.

If the stepper motor is disabled, the butterflies will not close fully at sero throttle but stay in idle position, reducing the motor brake effect. Is this correct?

 

[TURBO200R4]

In my mind, the butterflies normally are fully closed at sero throttle, when the bike is running, just to increase the motor brake effect. The butterflies will open slightly, when the engine is at idle to keep the engine running. This will be managed by the idle stepper motor.

If the stepper motor is disabled, the butterflies will not close fully at sero throttle but stay in idle position, reducing the motor brake effect. Is this correct?

just my opinion
while running the stepper motor it always stays open a little when u turn off ign it closes. i think that this is a safety to close throttle. now u also have the injectors that turn off and fuel pump so it is not likely to cause a hazard problem.

 

[Claviger]

For clarification for all, I didn't undo the linkage for 1 reason, easier to go back to using it in the future if desired, and it simply doesn't need to be disconnected. It was part of trouble shooting to ensure this was actually the issue.

The ideal way to solve this in 2019, is load TuneECU for android, read your tune, save it. Go to map options, then devices, and uncheck ISCV. Now it's disabled and no hardware changes were made, so you can revert at the touch of a button.

Regarding the time and check engine light, Alain has not responded, likely because he added "disable ISCV" option to the software, just not in your tune file for some reason.

I'll have a look at correcting it myself tonight since I saved your tune. I should be able to find a compatible map, copy all of your tables over, and use the software function to disable it.

Regarding secondary throttle open/close positioning etc:

It serves one purpose, and one purpose only, to limit power. The ECUs very rudimentary control strategy doesn't account for closed throttle over run, cold start, altitude, or airflow variance due to harmonics, it's literally there so Triumph can nanny you in low gears, that's it.

It doesn't help, or hurt, power delivery in any measurable way using stock cams.

 

[1K9]

For clarification for all, I didn't undo the linkage for 1 reason, easier to go back to using it in the future if desired, and it simply doesn't need to be disconnected.

Regarding the time and check engine light, Alain has not responded, likely because he added "disable ISCV" option to the software, just not in your tune file for some reason.

I'll have a look at correcting it myself tonight since I saved your tune.

Regarding secondary throttle open/close positioning etc:

It serves one purpose, and one purpose only, to limit power. The ECUs very rudimentary control strategy doesn't account for closed throttle over run, cold start, altitude, airflow variance due to harmonics, it's literally there so Triumph can nanny you in low gears, that's it.

It doesn't help, or hurt, power delivery in any measurable way using stock cams.

Thank you for the clarification Rob and your help. As you see there is a lot of interest in this common malady. I just looked at a spare throttle body assembly in the garage and taking off the linkage requires a cotter pin to be taken off in order to take off the arm. It looks like the assembly has to come off in order to do that. You approach to leave the disconnected motor ON seems to be a much simpler and reversible fix. If we are ever back together wanting to play mechanic after a run, Ill bring a spare assembly and replace the motor to see if it fixes the problem. The bike is running so well that I am reluctant to go back to the OEM set up. It's just HansO Tune rich, torquey and fast.

(Perhaps adjusting the linkage arm so that it can't reach the throttle arm might also fix the problem. It will give you funny values on TuneECU but the bike will idle without surging.)


As far as Scholle's comment/question.... Yes, the bike goes to 950 rpm with throttle closed and that might reduce engine braking but... I can use my brakes and a little throttle ON reduces throttle lashing. This is much better that an unexpected sudden surge to 2000 rpm while in a turn in a defective idle control motor set up. Ill tell you... it has been a Royal Pain to find this Fix.

Many others suffer and report the same dreaded "idle surge". FOR ME the Claviger fix has been to disable to stepper motor by disconnecting it and rising the idle at the main idle screw. IT WORKS! The only problem was "breaking" the original nut/idle stop factory set. This required 1. removing the secondary tps to get to the nut without stripping it. 2. Replacing and calibrating the tps. This requires the sensor to go IN a certain way and an Android phone that runs TuneECU that has the ability to see the secondary tps sensor setting. 3. Removing the secondary butterflies was part of the Mod.

If you have an intermittent sudden idle surge issue, go ahead and do all the lubing the motor and linkages, change the primary tps, check vacuum tubes and MAP sensor routine or whatever elase you think might fix the problem. If these do not fix the problem.... disconnect the idle stepper motor and see what happens. Be prepared to keep the bike idling with the throttle if you main idle is set low... or adjust the main idle screw when the bike is hot. Be prepared to live with a "check engine" light on until a fix for that is found.

 

[WyldCFH]

Do you have a spare stepper on that spare set of TBs? remove the stepper from the spare, plug it into the wire on the bike and see if the light goes out. If so, zip tie it out of the way and forget about. Then ride like the wind!

 

[TURBO200R4]

i was playing with my stepper motor bike running and unplugged the stepper it started and ran great with it unplugged..
so maybe u could while running unplug it then disable it with tuneecu and maybe everything would be fine and not set codes. ???

 

[Claviger]

Once disabled in TuneECU, it's totally off. No more stepping, no engine codes, no need to disconnect, actually, keeping it connected will protect the contacts better.

 

[1K9]

Once disabled in TuneECU, it's totally off. No more stepping, no engine codes, no need to disconnect, actually, keeping it connected will protect the contacts better.

Ill wait and see if that fix comes about. Cancel/disable the stepper in TuneECU and reconnect the motor to protect the contacts. In the meantime the bike runs guuud.

 

[1K9]

i was playing with my stepper motor bike running and unplugged the stepper it started and ran great with it unplugged..
so maybe u could while running unplug it then disable it with tuneecu and maybe everything would be fine and not set codes. ???

Disabling the stepper with TuneECU is a work in progress.