Need assistance

[YukonMP]

I have limited mechanical experience but a load of time on TY and there were one or two guys last season whose intermittent/warm running issues ended up being failing coils. Give them a read and see if they ring any bells. I just wish the damn thing would throw a code for you.

 

[TMBVLMP13]

I would love a code. Or even for it to do it consistently. It's really strange about 1/2 way home today it started running great. Then get home let it sit for 30min, sart it up and it starts acting up. Had a pair of test injectors injectors so i put them in to test and while installing them I noticed the boot from the throttle body to the head are wet on both cycl, nothing around them is wet just the boot. Best as I can tell the only thing that could cause that are leaking injectors. I put the test ones in made a mile or 2 run and it still did it. When I opened the throttle body while doing the injectors I could see a little fuel sitting on the lip for the rubber boot. Not sure what to think now.

 

[Royboy]

I would love a code. Or even for it to do it consistently. It's really strange about 1/2 way home today it started running great. Then get home let it sit for 30min, sart it up and it starts acting up. Had a pair of test injectors injectors so i put them in to test and while installing them I noticed the boot from the throttle body to the head are wet on both cycl, nothing around them is wet just the boot. Best as I can tell the only thing that could cause that are leaking injectors. I put the test ones in made a mile or 2 run and it still did it. When I opened the throttle body while doing the injectors I could see a little fuel sitting on the lip for the rubber boot. Not sure what to think now.

I guess if that you swapped out injectors, that would rule them out? I would think some fuel would be present with a throttle body system?
Can you get in there and unplug a plug or injector while it’s running poorly? Looking for a change?

 

[TMBVLMP13]

Not really. Rechecked connections and swapped out the ECM with a known good one still does it..

Does anyone know if the coolant temp sensor is used by the ECM to control fuel delivery by the engine temp? I noticed when it's doing it the idle fluctuate about 200-300 rpm. When it's running good the idle is at 1820-1850.
Dealer has no idea and can't get to it for a week to 10 days.

 

[Mooseman]

Have you checked what temperature it's running at? Maybe the thermostat is stuck open? Or it could be the temp sensor. If it's hot but the ECM still thinks it's cold, it will run in cold mode and dump extra fuel as if on choke.

 

[Royboy]

Could the anti-knock sensor act up? Retard timing or improper timing periodically ?

 

[Mooseman]

I think the KCS light would be flashing.

 

[Royboy]

I think the KCS light would be flashing.

I agree, most likely

 

[Mooseman]

Apart from overheating, it's always good to know actual running temperatures. That's why I added a temp gauge.

If everything checks out, I'd play with the fuel mixtures. I don't know why but I have a feeling this could be the issue. Costs nothing to try

Too bad these sleds don't have an oxygen sensor to adjust mixtures for different conditions and would throw a code when there is an issue.

 

[TMBVLMP13]

Hey guys I think we got er figured out. So i installed the temp gauge and adapter that Mooseman had in a previous thread, I was gong to do it anyway, but it became vital with this issue. Everything checked, out temp was consistent with the sensor. So I talked again to the dealer here and one in anchorage they weren't really any help, other than to bring it in in a week or so.
I had previously ordered some parts from Yukon Yamaha that weren't available here in the US and they seemed to know their stuff. So I thought, i can call them, got nothing to loose. They put me through to the service manager right away. We talked for a bit and he mentioned they had an issue with a unit going into rev, all the sensors including the TPS checked out, so they ordered a new harness, put the wiring harness in and it still had the issue. Turns out the TPS had a "issue". He mentioned to try that, he was pretty sure that was my issue. I wasn't too sure, but I found one off a "parts sled" and tired it. They are pretty spendy new, there wasn't one in town and I really don't like throwing parts at stuff. Installed the used one, set it according the manual and test drove. No further issues. I wasn't too convinced yet so I went caribou hunting this weekend and we put on about 130 miles. It never missed a beat, ran awesome over some really rough low snow tundra.
So here is a shout out to Yukon Yamaha, once again they came through.

Thanks guys!

 

[YukonMP]

Good to hear. Yes I feel pretty fortunate that they are my dealer. This stuff is never cheap but it is nice to deal with guys and girls that know their stuff and know what good service is.