Fast Idle - again

[redtrek]

Hello all (again)! So my bike has still been suffering occasional high idle speeds. I haven't been able to tell if it's the TPS or the idle stepper motor, but last night I unplugged the connector for the idle stepper motor. Today it's working perfect. I just have to hold the throttle open a bit for a minute after starting while it warms up. I do, of course, have the check engine light on. My question for anyone who has gone through this is does this mean that the idle stepper motor is bad or is it the sensor/computer that tells the ISM which position it needs to be in? Thanks for any input. I know there are a couple threads on this, but I hadn't seen any where someone had done this particular form of troubleshooting.

 

[redtrek]

The cable is cheap and the software is free, so that seems like it would be a good solution. Before I order the OBD2 cable, though, do you know if there is a conflict between using TuneECU and having the PowerCommanderIII USB on the bike? I know that I can use PCIII to reset the throttle position and fine-tune the fuel mix per cylinder as well as the overall fuel map. Would I just skip using Tune ECU for those functions and just use it for accessing the rest of the bike's computer information? I appreciate your help, IDK!

 

[Blastedbones]

The first thing to check is the Primary TPS. This can easily be done with either TuneBoy or TuneECU.

To add, is your TPS original? if so, it's almost certain to need replacing. They wear out & Triumph supply a more modern version now. I've been thru 2 replacements, & I think a few others have too.

 

[warp9.9]

Once I changed to the new style (blue innards) and added the .010 shim I have never had the problem since and that has been 40,000 miles ago. Over 60,000 miles and still have original Idle stepper motor. I agree with IDK and Bones TPS First.

 

[redtrek]

Once I changed to the new style (blue innards) and added the ,010 shim I have never had the problem. sense and that hads been 40,000 miles ago. Over 60,000 miles and still have original Idle stepper motor. I agree with IDK and Bones TPS First.

Thanks you guys! Warp, is that .010 shim for the mounting of the TPS? Do you know if that comes with the new TPS or is it something extra I'd have to look for like on bikebandit.com? I'm also planning to do a valve adjustment within the next couple of months as I've made friends with a guy who has every tool imaginable in his garage and he's offered to help with it. Having the shop manual from someone who previously posted it on one of these threads doesn't hurt, either. Can you recommend any other maintenance I should do while the valve cover is off? I've just replaced the spark plugs in December and had to zip-tie the leads for my cylinder 2 coil as they kept going open while riding. Lot's of fun! I've just turned over 30,000 miles and about a third of those are mine. I ride it pretty much every day as my commuter and my fun-mobile. Thanks again!

 

[DCRocket]

The shim idea I believe was Walt's, certainly not from Triumph - however, my 3rd tps has been running fine for 30K so haven't bothered to mount the shim yet. I think the old style tps was to blame --

 

[Fred F.]

To add, is your TPS original? if so, it's almost certain to need replacing. They wear out & Triumph supply a more modern version now. I've been thru 2 replacements, & I think a few others have too.

I thinks that's cause you twist the throttle to hard

 

[Fred F.]

Once I changed to the new style (blue innards) and added the ,010 shim I have never had the problem. sense and that hads been 40,000 miles ago. Over 60,000 miles and still have original Idle stepper motor. I agree with IDK and Bones TPS First.

I guess I haven't heard about the "shim". Would you care to expound ?

 

[owl]

I guess I haven't heard about the "shim". Would you care to expound ?

This was the original thinking from Walt (Hombre): The standard TPS is a poor fit against the throttle body. Consequently when tightened with the setscrew, a stress is applied to this extremely sensitive potentiometer. IMO, this has been causing the frequent failures. The shim keeps the TPS "square" against TB, alleviating that stress... and so far keeping mine from failing

The failures are probably related to over torquing from the recommended 3.5nm. I doubt even Triumph dealers use a torque wrench on the TPS... its too **** sensitive. The critical dimension is the thickness of your shim stock. If you look closely at the TPS against the throttle body, you will see that the TB is not flush against the TPS where the screw mounts. That gap causes TPS to "cock" when torqued. The .010" shim fills that slim gap.

Shim is cut from .010" aluminium. Note that one side of "circle" is flat to fit TB.

 

[warp9.9]

This was the original thinking from Walt (Hombre): The standard TPS is a poor fit against the throttle body. Consequently when tightened with the setscrew, a stress is applied to this extremely sensitive potentiometer. IMO, this has been causing the frequent failures. The shim keeps the TPS "square" against TB, alleviating that stress... and so far keeping mine from failing

The failures are probably related to over torquing from the recommended 3.5nm. I doubt even Triumph dealers use a torque wrench on the TPS... its too **** sensitive. The critical dimension is the thickness of your shim stock. If you look closely at the TPS against the throttle body, you will see that the TB is not flush against the TPS where the screw mounts. That gap causes TPS to "cock" when torqued. The .010" shim fills that slim gap.

Shim is cut from .010" aluminium. Note that one side of "circle" is flat to fit TB.

Toms right and it was walts idea. I think it also helped because the oval steel ring on the tps did not contact the throttle bodie completley allowing it to mount crooked. SO I still use it without any problems,





you can just see it below the TPS bottom between the tps and the throttle body