electrical gremlin

[kidwoo]

well I think I would have tried the air intake sensor relocate by now just because they say it improves starting. not saying thats it for you but just something I know I would try in your shoes. Also I think you've pissed this sled off big time running that fuel. EFI should compensate for elevation and lean the fuel spray. 84 is way too low imo. The one time I ran corn premium I noticed lazier starting and more backfires that ride and a couple rides afterwards too. It takes a couple tanks to flush that crap out of there completely. No bueno.
Also you said you ran a hillclimb tune on this thing with that fuel? broooo... Id seriously check your top end out.

No what I said was I run low octane UNLESS i've got some tuning going on. 91 exclusively with the advanced timing. My top end is just dandy.

It's not an octane problem. This is the third zuke motor I've had, and like the 9th sled I've had at this elevation. And the 91 up here sits in tanks much longer and I've already had two friends blow up motors 20 feet from a parking lot buying 91 from the same station one morning. I don't risk it and riding primarily above 8k, it's a waste of money. My sled actually runs worse on 91 really high. The 91 rec is for safety at sea level and I do buy it when I get lower. These sleds have knock sensors for a reason. Also like I've said earlier, I've run tons of tanks of 91 through it too and the problem still happens. It's not the fuel unless you want to talk about vapor pressure of each octane...that is very slightly different.

The sled starts and then goes dry. After the zillion pulls I've become accustomed to, hot stagnant air should be cleared out. Plus I end up with the hood off half the time it does this so the air temp sensor isn't even part of the equation. I suppose there could be a scenario where it gets a hot read, cuts gas, and then it won't get the initial ignition any more on dry cylinders. But if that's the case, it should eventually pump enough fuel down the line just like filling it up initially.

summ8rmk: I tested the voltage to it when when I switch the fuel pump, then again when I switched the entire main harness. It's fine. I haven't checked the injectors though. Let me see what my fuel line relocation does. I'm trying to narrow differences between the M-series and these sleds, because it only became a problem with the proclimbs.

 

[Rixster]

Try unplugging your water temp sensor next time it does it. turboed sleds had this issue for years. guys were installing a "hot start" switch in the water temp circuit. if that is the issue. the sled will start (super rich) with it unplugged. then you can plug it back in and you are good to go.

 

[kidwoo]

Try unplugging your water temp sensor next time it does it. turboed sleds had this issue for years. guys were installing a "hot start" switch in the water temp circuit. if that is the issue. the sled will start (super rich) with it unplugged. then you can plug it back in and you are good to go.

I have the hot start switch that cutler used to sell with their turbos. I use it when I put gas into a cylinder to restart it. Once it dies, the hot start switch by itself does nothing.

There are tons of threads on here with this issue. A lot of guys are saying they run the pump backwards first, and that sometimes it won't run forward before doing that. The vapor lock theory jives with that since the line would be pressurized and maybe the pump can't overcome it until you relieve the pressure running it backwards.

 

[kidwoo]

I just got back from a ride where I was intentionally putting the sled into the heat soak scenarios. Riding two up on a packed track for snowboard laps. Got the sled hot and then it sat for about 25 minutes while we grabbed another sled for retrieval. Sled started right up, ran for a few minutes........and then petered out right when I started rolling. Only difference this time was that it actually started after a few pulls with the hot start switch I've got.

I'll keep updating but I will say this: if you're experiencing this problem reroute your fuel line and put one of those little insulator wraps on it. Get it so it's not going OVER the damn pipe. This is the first time my sled has restarted without taking it apart. That's progress.

 

[2015 m8000 sno pro 153]

My 09 M8 had one of the wires that power the fuel injectors chafe down to a bare wire in one spot. When the engine got warm the exhaust heat shield by the Y pipe had chafed the fuel injection wire when it expanded from heat. Once the insulation had been worn off and the heat shield touched the bare spot on the wire my sled would die and would not start. After several hours, once the engine (and exhaust) cooled down the sled would start. This left me stranded.

On my 2015 M800, I have had it not start as well. Drives you bat sh!t crazy when everyone else in the group is ready to go and your sled won't start. I thought it was the Teth-air I installed but, it did it once I removed it as well. If I don't let it idle down before shutdown, sometimes it won't start. I think maybe the temp sensor is getting heat soaked? I even tried another ECU and it's better but, it still does it occasionally.

Sorry, that's about all I can come up with for you off the top of my head. I will be watching for the silver bullet to show up.

I have a 2015 as well and was out yesterday morning and same thing

My 09 M8 had one of the wires that power the fuel injectors chafe down to a bare wire in one spot. When the engine got warm the exhaust heat shield by the Y pipe had chafed the fuel injection wire when it expanded from heat. Once the insulation had been worn off and the heat shield touched the bare spot on the wire my sled would die and would not start. After several hours, once the engine (and exhaust) cooled down the sled would start. This left me stranded.

On my 2015 M800, I have had it not start as well. Drives you bat sh!t crazy when everyone else in the group is ready to go and your sled won't start. I thought it was the Teth-air I installed but, it did it once I removed it as well. If I don't let it idle down before shutdown, sometimes it won't start. I think maybe the temp sensor is getting heat soaked? I even tried another ECU and it's better but, it still does it occasionally.

Sorry, that's about all I can come up with for you off the top of my head. I will be watching for the silver bullet to show up.

 

[kidwoo]

Anybody know what injectors cat uses? They charge too much for cat to mail them.

And what's the real difference between the circle/square/triangle designation? Does cat test them and then that's their flow rate?

 

[2015 m8000 sno pro 153]

My 09 M8 had one of the wires that power the fuel injectors chafe down to a bare wire in one spot. When the engine got warm the exhaust heat shield by the Y pipe had chafed the fuel injection wire when it expanded from heat. Once the insulation had been worn off and the heat shield touched the bare spot on the wire my sled would die and would not start. After several hours, once the engine (and exhaust) cooled down the sled would start. This left me stranded.

On my 2015 M800, I have had it not start as well. Drives you bat sh!t crazy when everyone else in the group is ready to go and your sled won't start. I thought it was the Teth-air I installed but, it did it once I removed it as well. If I don't let it idle down before shutdown, sometimes it won't start. I think maybe the temp sensor is getting heat soaked? I even tried another ECU and it's better but, it still does have a 2015 as well just bought it for the way for Christmas went to the mountains yesterday and died after about an hour of writing tried everything plugs electrical checked the fuel line wasn’t getting fuel but heads parked and after waiting about 20 minutes and 1 billion pools later still nothing just a little fire and Die So fortunately I had cell service and googled it and after all the forms I had jumped up on top of the sled with one knee and put all my weight into it and drove it into the seat on top of the gas tank three times and the damn Sled fired right up soI don’t know what it is yet but apparently there is a check bowl in the stock fuel pump and not sure if you can get an aftermarket one but that’s what I will be trying first and I’m hoping that it does it again so I can confirm that by driving money into the gas tank it relieves the check ball in the pump

My 09 M8 had one of the wires that power the fuel injectors chafe down to a bare wire in one spot. When the engine got warm the exhaust heat shield by the Y pipe had chafed the fuel injection wire when it expanded from heat. Once the insulation had been worn off and the heat shield touched the bare spot on the wire my sled would die and would not start. After several hours, once the engine (and exhaust) cooled down the sled would start. This left me stranded.

On my 2015 M800, I have had it not start as well. Drives you bat sh!t crazy when everyone else in the group is ready to go and your sled won't start. I thought it was the Teth-air I installed but, it did it once I removed it as well. If I don't let it idle down before shutdown, sometimes it won't start. I think maybe the temp sensor is getting heat soaked? I even tried another ECU and it's better but, it still does it occasionally.

Sorry, that's about all I can come up with for you off the top of my head. I will be watching for the silver bullet to show up.

I have a 2015 as well the 600 clicks on it but for the wife for Christmas went riding yesterday and an hour and a half into it it died. It had spark And the plugs were dry. All connecters are good. Every 15 Pulls It would fire spuder and die . Buy fluke I was mad and had jumped up on the runningboards and drove my knee into the gas tank on top of the seat three times and what do you know it started so I think it may have something to do withThe check valve in the fuel pump.I’m waiting for it to happen again so I will keep everybody posted

 

[kidwoo]

Just fyi, a new fuel pump is one of the things I put in mine. So if you're correct, it's a design flaw, not a fluke.

 

[matt159]

Just fyi, a new fuel pump is one of the things I put in mine. So if you're correct, it's a design flaw, not a fluke.

I am adding a small fuel pressure gauge under the hood. Maybe it will help with troubleshooting down the road. only $25 for a gauge & a brass T... guess i am adding weight to the sled now.

I have seen the same style of injector that Cat uses on Ebay... but no good way to know if flow rates match close enough without a fuel injector test rack to measure fuel flow... and then you just keep buying injectors until you find a pair that flow about the same as your stockers. You could send your stock injectors to www.motormanfuelinjection.com. they will ultrasonic clean & flow check them for $15 each.
If yours are bad/failing they can get a flow rate off of the good one & then find you a matching pair to replace them at much better pricing than cat.
I used them for some boat injectors last year with good results.

Circle/Triangle/Square: Supposedly Circle is the leanest injector (richest ECU) & triangle is richest injector (leanest ECU). Square is in the middle of those two.
Not sure if someone swapped injectors out of my sled previously or if BDX was trying to fatten up fueling on the ProLites but I have a Circle ECU & Triangle injectors for whatever reason.. but runs perfect other than occasional hot start issue. From my 2013 cat. Same 3 part numbers (circle/square/triangle) through 2017.

 

[kidwoo]

I'll be curious to see what fuel pressure is on these no start scenarios. I've thought about doing the same just to test the pressurized line theory.

What's the likelihood of BOTH injectors being faulty?

 

[0neoldfart]

I'll be curious to see what fuel pressure is on these no start scenarios. I've thought about doing the same just to test the pressurized line theory.

What's the likelihood of BOTH injectors being faulty?

I know you mentioned a fuel pump replacement - did you replace the entire unit with pickup and harness, or just the pump? I only ask because The harness where it goes into the tank caused me some grief a few years back, drove me nuts as it would ground out periodically when riding, causing the same symptoms. Might be worth a look...

 

[kidwoo]

The whole shebang, float, harness, and the rest of the erector set.

 

[Suzzy-Q]

Have you ever had a recoil rope get sucked in from it fraying/braking? I’ve seen a recoil rope bunch up and push the trigger coils up and increase the clearance between them and the flywheel providing a weak signal causing issues before. Can’t remember what the gap is supposed to be but something to check.

 

[matt159]

Have you ever had a recoil rope get sucked in from it fraying/braking? I’ve seen a recoil rope bunch up and push the trigger coils up and increase the clearance between them and the flywheel providing a weak signal causing issues before. Can’t remember what the gap is supposed to be but something to check.

I have seen that personally as well... it is something worth checking. My experience was a won't-start-ever scenario once I shut it off. Ran fine for about 45 minutes back to the trailer after the rope broke, then wouldn't start at all after I shut it off.

 

[kidwoo]

I did break a rope once.

But it was only because of yanking the shlt out of it for half an hour every single time I went riding. In my case the problem way predated replacing the rope. And nothing changed or got worse after that.

 

[kidwoo]

I am adding a small fuel pressure gauge under the hood. Maybe it will help with troubleshooting down the road. only $25 for a gauge & a brass T... guess i am adding weight to the sled now.

I have seen the same style of injector that Cat uses on Ebay... but no good way to know if flow rates match close enough without a fuel injector test rack to measure fuel flow... and then you just keep buying injectors until you find a pair that flow about the same as your stockers. You could send your stock injectors to www.motormanfuelinjection.com. they will ultrasonic clean & flow check them for $15 each.
If yours are bad/failing they can get a flow rate off of the good one & then find you a matching pair to replace them at much better pricing than cat.
I used them for some boat injectors last year with good results.

Circle/Triangle/Square: Supposedly Circle is the leanest injector (richest ECU) & triangle is richest injector (leanest ECU). Square is in the middle of those two.
Not sure if someone swapped injectors out of my sled previously or if BDX was trying to fatten up fueling on the ProLites but I have a Circle ECU & Triangle injectors for whatever reason.. but runs perfect other than occasional hot start issue.View attachment 336840 From my 2013 cat. Same 3 part numbers (circle/square/triangle) through 2017.

Hey matt: learn anything with the fuel pressure gauge on there?

 

[matt159]

Hey matt: learn anything with the fuel pressure gauge on there?

1st trip west is in February. will let you know how my luck goes & what I find out.

 

[XCaSSAULT]

I’ve had my 15 m8000 for 3 seasons now and have always struggled with the “after it sits for 10-20min, it won’t start thing.” The longer it sits the worse it is.

Trip out west last week. I was dealing with it and my poo buddy came over and held the throttle wide open and BAM! Fired right up.

After that I pull with left hand, hold to the bars with right. It fires right up everytime just like everyone else’s. No more watching everyone else ride away. Doesn’t even matter if I let it idle down.

Yes I’m aware that this probably isn’t your issue but for anyone who’s been dealing with similar issues it’s worth a shot.

 

[matt159]

That is a good suggestion. It has worked for me many times also... but sometimes it is still a no go. so many possibile contributing conditions...

 

[kidwoo]

Just an update. I took it out skiing again which by its nature involves heavy loads and then letting it sit and heat soak. Multiple times started up and ran fine, then finally did the sputter and die right after starting. A couple pulls with the hot start switch and it fired up. So it's not cured but it's way better.

I think it's a given that if your sled has this issue and has been sitting a while, don't start it up and let it idle. Start it and go immediately. That gets the coolant and air stagnating in the air box moving through the system and back into reality. But it's definitely better since I rerouted the fuel line.