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Tardis 04-10-2013 06:47 AM

990 intermittent running issue
Greetings, am turning to the forum after not being able to have the issue rectified at the dealer. My 2010 990 Adv has for some time been behaving badly. After a period of slow and throttle happy running in traffic or trail it can develop a severe misfire that rapidly ends in no forward progress.
The engine appears to be fairly hot when it happens although the temp gauge does not indicate particularly adversely, I note the exhausts appear to be very hot.
The dealer checked the charging circuit, fuel etc but have only been able to replicate it once and then couldn't diagnose. Alternator stator and exhaust CO2 sensors have been mentioned as possible causes but they test OK.
It feels like severe fuel starvation, alas there is no carburettor to unblock ...
Has anybody out there experienced a similar issue and found the cause?
I am becoming slightly desperate, yesterday I found myself at the end of a track in the forest with a failing engine. I let it cool for twenty minutes then was able to get back to the tarmac after which it would only run for a few km at a time. I got to a roadside stop and force cooled the exhaust system and engine with buckets of water which seemed to enable it to run again. After a twenty minute freeway journey when it was fine it immediately started choking when I came back down to the city streets in Melbourne.
Today I ran it for half an hour at high throttle slow speed through two fan cycles ... And it was fine ...
Any prior experiences similar chaps?
Thanks for such an excellent and informative forum.

DELTATANGO 04-10-2013 07:42 AM

That sound like any over lean condition which will fuck up your engine. I don't know the cause but I wouldn't ride it anymore before getting it fixed.

Velociraptor 04-10-2013 08:29 AM

Bad fuel pump? Sometimes the pumps will start to fail like that. I had a similar issue with my 690 enduro and it was a poor connection to the coil. Could be so many things though.

what car?? 04-10-2013 08:30 AM

tardis when you say misfire, are you meaning a backfire through the exhaust? Does it seem perhaps more like a fuel starved issue than ignition? Were the coils checked out with an oscilloscope or other graphing meter? What about on the injectors? Perhaps the dealer doesn't have those kinds of tools at their disposal. What was the fuel output by the dealer? They've only had it happen once?

I have been experiencing something kind of like that, though my cans aren't super hot and the temp gauge seems about where it should be. Thought the fuel pump seems a bit hotter than I think it should be. But that doesn't explain any kind of backfiring through the exhaust (at least that's where I'm experiencing some kind of backfire, not extreme, but there none the less).

I keep thinking perhaps fuel starved, on a recent ride when it died I pulled the pump and tried to clean the sock as much as I could, couldn't access the main filter (no adequate tools). Still happened a bit later, running rough, choking, and wanting to die (did die momentarily a couple of times). The next day on the way back home from the Mexican border it started up again. Again I let it cool down; it happened a couple of different times. Once the temperature cooled down to around 60F and rain came in, it ran fine until the temp started to rise again.

The other day I reversed the polarity on the pump to try and purge the filters and test rode it. Took a little while, but again similar situation, but not as extreme as before. I also was down on fuel. I finally had a chance to refill and didn't happen the remainder of the short ride back home.

I wonder if it's something similar to what you're experiencing and not running lean, but pump is running hot and kind of vapor locking? Or filter issues? Guate city dealership does not have filters or pump in stock to find out if that's the cure.

Any thoughts from the orange gurus??

pdxmotorhead 04-10-2013 08:56 AM

Sounds exactly like a fuel pickup issue, and,, if your inlet sock is plugged you will overheat the pump which makes it worse.. This is based on my EFI experience, not KTM experience..

Once the engine goes lean its going to heat up worse,, and then the problem spirals downward.. As the lean engine symptoms distract from the real problem.

If the dealer cant help you,, see if you can track down a decent sports car or bike race tuner (Track/Road racing not ricer drag action) They can hook up to the engine with their gear and see whats working and whats not.. a couple hundred spent on someone who knows there stuff is cheap compared to a gorilla throwing parts at it..

Bad injector will cause hot pipes as well, but normally that should throw a code..


gefr 04-10-2013 10:29 PM

I had similar issues on my 990Adv.
In hot weather only, the bike bogging and dying. Struggled with that for a while. Fresh fuel cools the fuel down and runs better for a while. I finally left it in a dealer. He installed a pressure gauge in the fuel line and diagnosed a failing fuel pump. I believe you have the same issue.

Tardis 04-11-2013 03:48 AM

Thanks very much for that. I gather then that the fuel pumps are a weak point with the 990adv ... Earlier in my relationship I had a high rpm misfire that the dealer said was a blocked fuel filter and thus not warranty ... It cost me several hundred dollars and some perplexity at the time and thus money it took for the dealer to diagnose.
For the life of me I cannot understand why a vehicle of this nature has the pump and fuel filter hidden inside the fuel tank in such an unserviceable fashion ... Pain ...

TcRulz 04-11-2013 03:00 PM

Hi Tardis, 990's have a bad reputation for blocking filters. Dalby moto in QLD sell a efi filter purge kit that reverse the pump and pumps fuel backwards, cleaning the filter. They have a legendary reputation in Oz so might pay to give them a call.:D

gefr 04-11-2013 04:37 PM

The fp is placed inside the fuel tank to cool off.
It also has to be as low as possible to use the whole of the tank capacity, so there you go.

pdxmotorhead 04-11-2013 04:43 PM

Having the pump immersed in the fuel keep it cool, unfortunately it heats the fuel up..

Pretty much all cars now have the same setup...


what car?? 04-12-2013 12:49 PM

I kind of wondered when I might have this issue act up on me. Didn't bring extra provisions with me. Damn the luck!:D

Having the pump immersed in the fuel keep it cool, unfortunately it heats the fuel up..

Pretty much all cars now have the same setup...


Actually the pump is not hard to get to or remove. Try a full tank of fuel and replacing the pump on a truck or car without the use of proper jacks or shop to do it in. :rofl. Good stuff for sure.

Looking forward to getting her back on track without the hiccups.:clap Great sight and useful/helpful tips and advice... :freaky

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