Author Topic: Stalling Off Idle?  (Read 466 times)

FatDrunkStupid

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Stalling Off Idle?
« on: April 12, 2015, 06:11:07 am »
Apologies for all the questions from a forum newbie. Y'all have caught me during a period of clueless spannering.

I have a 2011 with an Akrapovic silencer. The bike suffered from terribly snatchy FI when I acquired it but I've almost completely cured this by switching the paper air filter for a KTM "off road" foam filter, installing a G2 throttle cam (using the "medium" cam profile) and installing the Evo 1 maps via TuneECU. With this setup the bike (finally!) runs perfectly with wonderfully smooth throttle response and none of trhe previously-experienced popping and banging when overrun. However... when the engine is hot it has a tendency to stall off idle or at low revs (when approaching a road junction for example) and while it restarts easily enough, it usually takes 2 or 3 attempts before it will run without immediately re-stalling when I touch the throttle. This is somewhat irritating.

When I installed the Evo 1 maps I did the throttle calibration and 15 minutes adaptation processes (during which the bike stalled a couple of times but was immediately restarted as per recommendations). While doing due dilligence and searching the 'net for a solution to this problem, it became clear that there's no universally-accepted solution, probably due to the fact that there seems to be so many variations of the symptoms.

So, my question is whether any of my betters (but not necessarily elders) on here have any suggestions on how to approach this? TPS check/reset? Would simply raising the idle speed resolve it? I ask rather than try because while I've been riding and stripping small-bore 2 stroke trials bikes for years, the apparent complexity of this FI-ed 4 stroke still scares me right now. All comments and suggestions are much appreciated!

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Guymcfly

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Re: Stalling Off Idle?
« Reply #1 on: April 12, 2015, 07:12:37 am »
First up, does it happen when you chop the throttle?
Second, have you changed your clutch lever (I'm serious about this)?

And also try this...because I think some dirt/dust/crud has got in your tank during assembly and may have fouled your injector.

Pop you air box. Unscrew you fuel injector screw (use the supplied screwdriver for this), unplug harness and pull out you injector. Watch out for the o ring...don't loose it. Activate your injector with a 9 volt battery and a couple of wire/clips and and spray contact cleaner thru it. Then spray compressed air thru it.
Or drop down to the nice man at the local garage and ask them to clean it. It should cost you squat.
Reassemble. Make sure you seat the o ring properly or it will leak.
Enjoy as you marvel at the benefits of having removed the crud from your injector.

Remember to do this every time you service, clean or otherwise tinker with you orange beasty.
« Last Edit: April 12, 2015, 07:28:14 am by Guymcfly »

Guymcfly

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Re: Stalling Off Idle?
« Reply #2 on: April 12, 2015, 07:19:59 am »
« Last Edit: April 12, 2015, 07:24:24 am by Guymcfly »

FatDrunkStupid

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Re: Stalling Off Idle?
« Reply #3 on: April 12, 2015, 02:43:54 pm »
Thanks for the sage advice. I'll give it a go and report back  :)

FatDrunkStupid

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Re: Stalling Off Idle?
« Reply #4 on: June 15, 2015, 12:40:12 pm »
OK, I know it's been a while but I thought I'd better report back on this one since it seems to be a pretty common problem.

I followed all the advice in this thread and elsewhere. I did:

1. Airbox out, clean injector - problem marginally improved but still there.
2. Airbox out (again), adjust TPS (THAD/APAD values) - all OK, no improvement.

Then, while re-mounting the airbox and preparing to break out TuneECU yet again I noticed a gap between the (Evo 1) lid and (foam) filter on both sides. No idea why I didn't notice this before. I pulled the filter and the inside of the airbox was clean so I put it back together and ran a bead of silicone around the 'box/lid joint. Waddaya know? Problem solved! Constant idle speed, no choking or stalling!

So, too lean at low rpm apparently. One more for the checklist.

Many thanks for everyone's help!