After some ideas on a very intermittent problem we have with my wife's 2013 Slim.

Problem started 18 months ago for no real apparent reason. Bike would start idling either fast (up to 1700rpm) or low to to point of stalling. Usually it would idle fast when downshifting and stopping at lights, then it would switch to very low idle and stall. Misfiring and carrying on. If we were on a ride and stopped for a 45min drinks break it would not restart without cranking the throttle wide open. Plumes of black smoke would billow. Next few times riding there would not be the slightest issue. Then the problem would pop up again. Took it to our mechanic who is an independent HD trained tech, with an outstanding reputation here on the Coast. He checked fuel tank internals and changed the filter. Checked for inlet manifold air leak, found one so replaced all seals. Cleaned IAC. Bike ran fine for a month, then started the same b.s.. 

Replaced IAC. No difference. I should mention that there were no DTC's thrown. Went through the process and changed out all inlet sensors as well as CPS. After this, bike ran good for almost a year. I should also mention that this is so intermittent, we've left it with him for a couple of weeks, where he's ridden it every day and it hasn't faulted!

Anyway, we had it in his shop for 5 weeks recently to have the front end powdercoated. Maree picked it up after completion, got 2km down the road and the fuckin thing started doing it's farting stalling thing again. GOT IT restarted, straight back to the workshop, running like a dream. Hooked up to the SERT. Nothing out of the ordinary.. rode home,  no further issues. Fast forward a couple of weeks, just doin a short local loop up a tight hilly road (1st and 2nd gear) starts fumbling a bit. Across the top then back into traffic in town. Thru a set of lights, missing, coughing and dies all together. On the ph, the tech comes out. This time it's thrown a code for ETS fault. We restart it after maybe 30mins with no probs. Back to the workshop and sensor replaced. All good we think. Have done maybe 400km since then with no probs. GOT out today rode for 25km at 80kph all good. Slow dow/stop for lights - idling at 1700rpm. Fuck. Next set of lights same deal. Next set running ok. Next set, wants to idle slow, bout 750rpm. Stop for fuel, a bit hesitant to restart. Carry on a bit further and end up in gridlock traffic. Stop n go shit. Bike missing farting etc. Dies all together. Restart by cranking throttle wide open. Get out of the traffic and on to the highway all ok. Get off to head for home thru a couple of T intersections. Missing wanting to die. Have to keep the revs up to keep it running. Get home, again after 15-20km of 80kph, bikes running perfect. I took it for a 30min run and tried to replicate all the shit we'd just been thru and it didnt miss a fucking beat! Anyone got any ideas? The only sensor that hasn't been changed (I think) is the VSS, but there have been none of the other symptoms that go along with this, e.g.  Speedo fluctuations, turn signals not cancelling.

I'm sorry this is so long and drawn out, but it's got us fucked. 

Help anyone??

I chased a fault on mine for a long time, idle related.

All sensors checked out well, i think they are fairly reliable, same stuff for automobile world.

You have to check all wires are working, no shorting, wires that have to bend to get to sensor or fuel injectors

But I believe the intake manifold seals are the cause of a lot of these issues, stick with HD ones, make sure clamps are on correct way, make sure air cleaner backing plate is on when you position and tighten throttle body down, use Vaseline 

Cheers Robots. Manifold seals replaced and rechecked.

It's getting to the stage of replacing looms or ecm and seeing what happens. Bloody costly business. Because the fault is so intermittent, it's almost impossible to track down. I even had the idea of leaving the SEPRT plugged in and recording continuously, so that it would just over-write until the problems started, then we could stop recording and review. Used to be it would record for 1 1/2 hrs then just keep overwriting data until stopped. Now it will only record for 15mins and does not overwrite. Thanks EPA.

Maree has lost all faith in the bike and now doesn't trust it. Can't say I blame her.

need the wiring diagram in the manual. follow it through with multimeter as VirtualT advised. Probably have to lift tank or remove throttle body to get good access.

this takes time, I would do at home. Need to write everything on paper.

no point changing ecm or main wiring loom if no fault is found. If fault is found to lets say IAC harness then a new wire could be put in from IAC to ECM

if high kms i would change throttle body clamps also, could be warped. Not a lot of mechanics want to install the throttle body with air cleaner backing plate attached to it as not much room to install and tighten bolts, but its the only way to "center" throttle body otherwise air cleaner backing plate will move it when installed. 

no check engine light when riding, so sensors and wiring are operating as the ECM getting signals all the time

Been plenty of instances of sensors failing with no fault code.

then presto when you get back into town, roundabouts, intersections up goes the idle

check your wiring first using the service manual

what if

could there be a bit of cloth or sponge in your tank as you are weaving about it covers the outlet letting minimal fuel through, turn the other way the fuel moves it off, say when you turn left is the worst

the only starts with full throttle could be it is settled on the outlet on the side stand (left),

your sensors will be reading the engine needs more fuel and open up for more (high Idle), then the ECU will tell it there is to much fuel and the low Idle/stall

the cloth/sponge would not make any sound when tank was taken off and the tap checked or shaken and could get stuck to the side of the tank out of view on a visual inspection

just a thought, one of two things can happen, you find something in there or I have wasted an hour of your time

Cheers Pete.

1100km run to Monto and back a couple of weekends ago, 500km this weekend and no problems at any stage. Fingers crossed. Maybe a faulty battery cell breaking down under certain conditions?? I hope that's it anyway.

Will keep that in mind