Idle issue killing me

[Rocket Scientist]

I would un-hook the battery for a couple minutes. That will reset the adaptives. See if that helps. When I check for vacuum leaks, I use a spray bottle and water. Using a flammable gas will work, but after you've sprayed enough of it, it can be picked up by the intake and cause changes in the speed of engine, thus skewing your results. Learned that from one of my auto mechanic friends. If you rule out a vacuum leak, I would be looking at the cruise control next.

 

[Joesmoe]

What does the water do ?

While I would not rule out anything out of hand, the cruise control is off, and as such, has only the mechanical connection of the throttle spool, which is locked down and was not disconnected for the cam work. There is throttle free-play - even extra now just to ensure there is no tug on that.

 

[Rocket Scientist]

What does the water do ?

While I would not rule out anything out of hand, the cruise control is off, and as such, has only the mechanical connection of the throttle spool, which is locked down and was not disconnected for the cam work. There is throttle free-play - even extra now just to ensure there is no tug on that.

If there is a vacuum leak, it will draw in the water and cause the engine to stumble.

 

[SuperTED]

I have now similiar problem- high iddle at start (2000RPM), stays for a while, then drops to 900RPM, and again when i Neutral get high idle, for about15-20seconds and goes back.

Checked TPS with TuneEcu- did the ISCV calibration to 60/72 volts as per Tune ECU guidance, and still the same problem.

Did some different values like others succeeded doing 66/77volts- no luck.

TuneEcu clearly shows correct TPS values, Secondaries are 100% oper as per map loaded to the ECU.


I have removed today the locking nut from the Idle Stepper motor- which controls the Idle RPM, and the problem seems to dissapear.

I found this just disconnecting the cable from the stepper motor-that gave a fault code and engine check lamp on speedo, but stopped all the iddle issues.

That was the idea to just take the locking bolt off, before i ordern ew stepper motor, that way it does notcome with any faults codes.


Anyone else had the same issues with stepper motor?

 

[Joesmoe]

Yes, had that issue.

The really odd thing, is the bike was fine, before I disconnected a bunch of stuff in order to change out the camshafts. Upon putting everything back together, had the high idle problem, just as you describe.

I too went through the process of ISCV and reset adaptives and balanced the throttle bodies - made it smoother but did not resolve the high idle.

Out of desperation, I ordered and fitted a replacement stepper motor -- fortunately, in the U.S. at least, they're not expensive.

That action seems to have solved the high idle issue. Now, on starting, it goes up to about 1,200 for about five seconds, and then settles.

There is a recommendation from some knowledgeable folk here, that if the idle issue cannot be adequately addressed after checking connections and settings, they advise doing what you did, and simply disconnect the stepper motor at the physical actuator end - and that would have been my next step.

Good luck.

 

[TURBO200R4]

from what u said i think that it is normal for it to spike up a few times when u first start it.

 

[Rocket Scientist]

Here is my theory after having this bike for 10 years. On my bike at least, it starts with engine taking a little longer than usual to return to idle. Then it will start doing the high idle at start up. If I hit the kill switch and restart then it idles normal. I think some of the adaptive's in the program get skewed over time. Now days, I hook up tuneecu, without changing anything, I run it through the idle stepper reset procedure, and reset the adaptive's. That fixes it for a couple months. Usually have to do it twice a season.

 

[SuperTED]

It only can mean you stepper motor is sending wrong data to ECU and needs replacing.

 

[1K9]

Here is my theory after having this bike for 10 years. On my bike at least, it starts with engine taking a little longer than usual to return to idle. Then it will start doing the high idle at start up. If I hit the kill switch and restart then it idles normal. I think some of the adaptive's in the program get skewed over time. Now days, I hook up tuneecu, without changing anything, I run it through the idle stepper reset procedure, and reset the adaptive's. That fixes it for a couple months. Usually have to do it twice a season.

That was a Gurulikesque vignette of KISS solution to a common problem. Scrub the software, Brilliant !