Hanging Idle

[Kevin frazier]

I have had this issue and the way i dialed it in on my hot rod after the last tune it would idle crazy when i pulled in clutch to come to a stop. I test rode bike and it was warm, when i came to a stop and it idled high i leaned over with the 7mm wrench and very easily adjusted stepper nut, very small adjustment till idle was corrected, did this twice to get dialed in perfectly so when i pulled in clutch to stop idle acted correctly. Yours may very well be tps but that is something i did to correct the high idle surge, with built motors it seems the .62 to .72 doesn’t quite get it.

 

[Kevin frazier]

I also run my tps upto .64, also visually check butterflies closing and cable or stop not keeping it from doing so

 

[RockOn]

I have had every one of the pain-in-the-butt idle symptoms but have so far resisted replacing anything, not tpms's, not messing with the EMC brains, not anything. Currently bike is running fine and at start up it runs up to 1800-2000 rpms for a moment or two then settles down to 850-900 rpms. last week I had exactly the same symptoms you have. This week it is gone. My habit has been to pump throttle several times from max to min before turning on the ignition and then do it several more times with ignition on before starting. Usually results in good idle. I think Turbo is on to something about the springs. Anyway, spraying silicone on the throttle springs from time to time has been a big plus for me.

 

[Fungames43232]

Going to try these things this weekend

 

[Fungames43232]

Ok still battling the hanging idle. Next question. I replaced my TPS and now thinking, maybe I just got a bad one. My question is, after you tighten the TPS. Do you still see a variance in the TPS voltage when you wiggle it or is it rock solid on .60?

 

[Rocket Scientist]

I battled my idle stepper for years. Tried everything twice. After it decided to idle at 2 grand all day on an out of state group ride, I said fark it and took the stepper motor off. That was two years ago.

 

[Rocket Scientist]

If you haven't already, balance your throttle bodies. Try doing it at slow idle speed. That is where it is the most critical for good idle control.

 

[Fungames43232]

I did balance the TBs. Unfortunately when I blip the throttle after adjustment it can over 3k and stay there. Previously I did pull the stepper motor plug and it didn't help. Maybe I'll try again. Still bugs me that the TP changes voltage when I wiggle it. Not sure if that's normal. Did it with the old and new TPS.

 

[Rocket Scientist]

We used to cut a little shim washer out of an aluminum can to go under the screw on the TPS so that it sat straight when tightened. Also don't over tighten the screw. Personally, I think it's a poor design. Fuel injected auto engines don't have idle problems. I've driven several cars over 200,000 miles and have never changed a TPS on any of them.

 

[Kevin frazier]

I did balance the TBs. Unfortunately when I blip the throttle after adjustment it can over 3k and stay there. Previously I did pull the stepper motor plug and it didn't help. Maybe I'll try again. Still bugs me that the TP changes voltage when I wiggle it. Not sure if that's normal. Did it with the old and new TPS.

adjust the 7mm adjustment nut on the stepper when it runs up in rpm when you blib throttle., while running. This will lower that hanging rpm, adjust that nut slowly you dont turn it much at all, 2 or 3 flats, adjust to where it idles normally. Then if it hangs up again on a blip or retuning to idle adjust in the same direction before to make normal. I have gotten rid of that annoying high idle by doing that. I have ridden down road with box end 7mm in left hand and bring to fast stop and if the idle runs up i lean over and make tiny adjustment, you can reach from seat on bike in neutral no problem