Riding done but sled won’t run. Need help!

[1madbird]

I know most people are not watching snowest threads but hopefully some of the die hards are still check for new posts. This will be long so bare with me. So I have a buddies 2016 Axys with a boondocker turbo. Last year it broke the engine mounts and destroyed the case and the Voltage regulator when the belt blew. It is all back together and on the first ride in December it only made it about 1 mile down the trail. It over heated and died and could never get it started again. The dealer has had it for 4 months and could not solve it. They installed a new stator but still would not start. He brought it to me to see what I could find. I got it back and first unhooked the boondocker box and it fired right up. Stopped and started a few times and it was all good. Sent the box to boondocker and they said it was bad. Awesome I thought I had it fixed for sure. But wait got the new box back and it’s the updated Auto adjust. Plugged it in and it fired right up. Started and stopped it a bunch of times and got it up to temp after about 10 minutes of running, it won’t start crap! I have checked fuels system has around 60 psi. Checked spark it has spark but seems weak. Reset the TPS all good but idle is too low at the 940 spec. When I can get it running it’s so low it will die. Checked the Voltage regulator as per the manual and it seems good. Check the stator ohms it does not match the book specs they are all higher ohms then the book says, but no shorts or grounds. I have narrowed it down to a fuel issue. If I unhook all the harnesses and let it sit for a few days then plug it all back in it will start but once it gets hot it won’t restart. If I use a shot of starting fluid it will start and run but once you shut it off it won’t restart. So for some reason the injectors are not firing. Anyone got any ideas? Could it be injectors or is my stator not producing enough power. Can you test the stator output when cranking?

 

[gdn]

Are you saying even after it's warm you can give a shot of ether and it will start? I would not think stator if that's the case. We had a similar issue last winter with a Boondocker turbo - stopped for a break & would not start. Finally got pissed after about 20 rope pulls & just went old school & held the throttle wide open & it started right up. I know it's not supposed to work that way but it did on 2 separate occasions. Don't know if the injectors fire an extra shot of fuel on shut down sometimes & just floods it enough to keep it from firing up like normal. We have gotten real careful about idling for a few seconds before shutting down & that seems to have helped some.

 

[1madbird]

Yes when warm if I give it a shot of either it will start. I have tried holding the throttle wide open it still won’t start. I am thinking the stator because if there is not enough voltage the injectors may not fire. Once it fired the voltage goes up enough to keep firing them. It just concerns me because the dealer said they put a new stator in it.

 

[gdn]

If you pull a spark plug does it actually have spark when it has been warmed up? I know stators can go bad but I've been around these things for 40+ years and have never actually had one go bad on me. That being said it sure sounds like something electrical that doesn't like heat and that could be a stator. I did have a regulator go bad a few years back & the sled would shut down when it got warmed up then start up like normal when cooled down. On that one it would give a bit of warning tho by the dash going off a couple minutes before complete shut down. Not the same symptoms as you are having but if you have another sled with the same regulator it's an easy swap to try. Just trying to rule things out.

 

[wfieldin]

Have you looked at your reeds?

 

[1madbird]

GDN I have taken the spark plug out and I can’t see any spark. If I power up the ECU with a 12 volt battery I get great spark. But I have one of those spark plug window tools that lets you see the spark with the plug installed and it does show spark. I have my doubts that it’s the stator also but It could have got damaged due to the VR failure and engine rebuild or when the dealer installed the new one.

(Have you looked at your reeds?)
I have not physically checked them but I am certain that the dealer did because they completely tore the engine down looking for something wrong. I don’t think reeds would cause a no start and especially not intermittent.

 

[1madbird]

Also one other find is that I’m starting to believe that it may not be temperature based. After the last time running it and it wouldn’t start I let it sit for a few days and tried to start it and it wouldn’t start. I hooked up 12 volts to the ECU external power connector and after a couple of pulled it started. I can then unhook it and it will start. But then once it gets hot it won’t start again. It seems like it just does not have enough voltage to fire the injectors durning cranking. If it had electric start I think it would start every time but not certain.

 

[t30mg]

Do you have another ECU you can try? I found an intermittent gremlin living there once...

 

[gdn]

You said it destroyed the regulator, is it possible it did some damage to the wire harness so it is getting faulty voltages to the ECU? Just bouncing ideas around.

 

[1madbird]

The owner has another sled that I am going to try and get to use for testing.
So can try the ECU.
As for the harness it all looks good and I don't see anywhere that has a problem. I guess I will need to go through all the wiring again.

 

[t30mg]

We had a harness issue as well last winter on a 16-800.
Would die and re-start sometimes over and over and sometimes wouldn't die at all.
Was setting the tps with indy dans tool and noticed the voltage came and went as we turned the box to see the screen.
Turned out to be a bad connection on one of the pins in the harness plug for the ecu.
Next time you have the sled running, put some lateral tension in different directions on the harness close to where it plugs in and see if you can make it miss or die.

 

[1madbird]

Update. Last night I went through all the stator connections and ohmed them out and verified that resistance was with in spec. It all checked out right on and so I started following the orange boost circuit that is used to power the fuel injectors and pump. I found that one of those orange wires going to the ECU on pin 26 was pushed out. Again I was hoping this was the fix. Well it was and it wasn't. It started and idled high. I previously had to turn the idle up because it would idle. I reset the TPS to spec and it started and idled perfect. Got ot hot and still started. I thought I had it for sure. Started tying up the harnes and got all tied up and the connector bags on. Went to start it and no start. Got it started but wont idle again. I can not believe this. Anyways I know for sure it's a harness issue somewhere with a connector or something.

 

[el__gato]

ya, some of those Polaris wiring setup's..... like something you'd find on a homemade trailer, maybe not as good even. Looks like you are onto it now. Good luck.