Crank seals, Injectors, Fuel Pump, ?

[tdbaugha]

I have an interesting running problem that I've been trying to diagnose for 2 weekends.

Whenever the sled is hot and I give it WOT, the sled will bog. When the sled has cooled down, I can hold it WOT for ~10-20 seconds or more before it will start to bog. I am not seeing any lights on the gauge when the sled cuts out. The running issues started ~4 weeks ago with the random instances of loading up on the bottom end. Then the WOT bogging started ~3 weeks ago but only happened after 40-50 seconds of WOT. It has slowly progressed to cutting out almost instantly if I've been riding it hard for 20 seconds or more.

For diagnostics purposes, I held it WOT on the trail after it started to cut out and it has a pretty consistent noise of what sounds like the ECU cutting ignition(holds pretty steady RPM and has a repetitive bog-bog-bog-bog-bog exhaust note).

I thought the EGT sensor was starting to get faulty and causing the ECU to cut ignition. But today, I swapped EGT sensors with a working sled and it makes no difference. I'm starting to lean towards a bad crank seal, injectors, or fuel pump causing a lean condition which is being picked up by the EGT sensor and causing the ECU to cut ignition.

Sled is 2012 800 with about 3000 miles. This is the first problem that I've had with the sled. Engine is stock with an SLP pipe and PCV with the SLP map.

 

[Scott]

I dunno about your symptoms...but I had a crank seal go on mine. 1250 miles.

I was buzzing down the trail on Jan 4th. Straight stretch, about 2 miles from the truck. Water temps were in low 150s (scratchers are bent and not working well).
Pinned it and held for a few seconds. Tach hit 8600 and hit det lock. Shut it down and fired it up again. Fine.

Headed down trail again...pinned it. Det lock. Crap.
Babied it back to trailer.

Took it out on Jan 16th, MLK day. Had a slightly different note to the exhaust. The kids wanted to go into the warming hut for short one (7miles one way). Couldn't put my finger on that exhaust note. Just wasn't the same. Ran fine though. I saw 8600 on the tach. I did notice that. Wasn't sure why, because it never went above 8450 before.

A buddy was riding it Feb 1st weekend (his new XM threw a rod at 300 miles or so).
He helped a buddy dig out of a hole. Came back to sled. Started it. Let it idle. Water temps said 140...cooled down 5° at a time...and then dropped to 105. Sled made a pop and shut off.

He said he immediately pulled chord and it started again, but ran at high idle...like 2500. Never came down. He babied it all the way out about 9 miles. He said it ran WELL. Put it on a hill on the way out and it was fine.

Never idled below 2300. LOTS of REALLY deep snow that day. Thought maybe throttle block needed a thaw. Brought it home, warmed it up for 24 hours...no change. Idled at 2300 and up.
Sounded weird. Deeper sounding notes. Had a bit of a surge and uneven idle.

Took it into dealer. No codes. All was good.
Revved higher when sprayed with ether around intake.
Had an air leak somewhere in there I guess.

Took it apart...and voila...crank seal went and lost PTO bearing.

 

[Dirty Steve]

Have you ever changed your fuel filter?

Sent from my DROID RAZR using Tapatalk

 

[tdbaugha]

Put a new OEM fuel filter on 400 miles ago.

 

[steepndeep800]

I had a 11 that acted bad like that turned out to be worn out piston/rings. comp check was ok but leak down was not. piston rings solved the issue

 

[tdbaugha]

I just put in '14 pistons and rings about 400 miles ago.

I have been told by some friends that chipped/broken reeds can cause a cylinder to flame out at WOT so I'll be pulling those tonight.

I've also been told by two dealers that it sounds like a classic TPS issue. I'll be building a tester and checking/recalibrating that tonight as well.

 

[cateye5312]

Ugh, I hate problems that only happen when they're warm, tough to find in the shop. To me it sounds like a worn resistor or plug wire that is not functioning properly when the under hood temps rise. It really doesn't take much for something to expand just enough to cause a problem. Good luck.

 

[tdbaugha]

Definitely. I have 2 spare sets of ignition coils, wires, and caps that I can try to find the best fitting caps too.

Went to RadioShack today and none of the 3 5V regulators they had were outputting 4.99-5.01V. Soooo I wont be checking the TPS.

 

[xc6rider]

Definitely. I have 2 spare sets of ignition coils, wires, and caps that I can try to find the best fitting caps too.

Went to RadioShack today and none of the 3 5V regulators they had were outputting 4.99-5.01V. Soooo I wont be checking the TPS.

Use a good car battery, and power up the ECM! Test it that way, and back probe connector at the ECM.

 

[Newby2sleds]

Use a good car battery, and power up the ECM! Test it that way, and back probe connector at the ECM.

x2 Found this to be the easiest way. I set out to build a TPS tester and ended up making my own "Plug" for ECU port and connecting to a GOOD car battery. This way you should see the same voltage as when the sled is running.

Have you done a Comp check?

 

[tdbaugha]

Use a good car battery, and power up the ECM! Test it that way, and back probe connector at the ECM.

Which pin is the TPS signal?

No I haven't done a compression test but I am almost certain its fine. It has a fresh top end and it runs great till it bogs.

 

[polarisperformance]

Mine was acting like that and I try many thing ,no engine code , new injector, new fuel filter and I test everithing that can be test,,,, finaly I install my power commander and leaned it on top ,,,, now my sled seem to run very well.


try with ethanol and non-ethanol plug ,,, the ethanol plug send 5 % more gas,, then if it's worse when you are on the ethanol mode .... probably you need to lean it on top WOT RPM...

My sled was always running good the first 2 1/2 years then I start to have this problem .... this over fuelling cause my engine to seize because is has washed the oil on my cylinder ( I was at the very lean oil setting form factory)

But I can't say what is causing this over-fuelling issues

 

[Scott]

I just put in '14 pistons and rings about 400 miles ago.

I have been told by some friends that chipped/broken reeds can cause a cylinder to flame out at WOT so I'll be pulling those tonight.

I've also been told by two dealers that it sounds like a classic TPS issue. I'll be building a tester and checking/recalibrating that tonight as well.

Reed chips and problems like that tend to run rough with a burble on the bottom end, but then after you get past a certain RPM, they clean up and run well in mid range and top end.

 

[xc6rider]

Which pin is the TPS signal?

No I haven't done a compression test but I am almost certain its fine. It has a fresh top end and it runs great till it bogs.

Check out this post... It gives the pins you need to back probe etc...
http://www.snowest.com/forum/showpost.php?p=3470019&postcount=29

Be careful how you back probe. You can use long needles, or a paper clip if you hammer and file to down til it's small and very smooth.

Their is a clear 4 pin connector that hangs down above the center of the head, that is unused... It has a red/white wire, and you can check your reference voltage there, so you'll only need to back probe one wire at the ECM for setting TPS voltage.

Also, to check the base setting voltage, you need to unhook the throttle cable, and back the idle adjust screw away to verify the throttle plates are fully closed. Didn't know if you're aware of all that.

 

[MISER]

I have an interesting running problem that I've been trying to diagnose for 2 weekends.

Whenever the sled is hot and I give it WOT, the sled will bog. When the sled has cooled down, I can hold it WOT for ~10-20 seconds or more before it will start to bog. I am not seeing any lights on the gauge when the sled cuts out. The running issues started ~4 weeks ago with the random instances of loading up on the bottom end. Then the WOT bogging started ~3 weeks ago but only happened after 40-50 seconds of WOT. It has slowly progressed to cutting out almost instantly if I've been riding it hard for 20 seconds or more.

For diagnostics purposes, I held it WOT on the trail after it started to cut out and it has a pretty consistent noise of what sounds like the ECU cutting ignition(holds pretty steady RPM and has a repetitive bog-bog-bog-bog-bog exhaust note).

I thought the EGT sensor was starting to get faulty and causing the ECU to cut ignition. But today, I swapped EGT sensors with a working sled and it makes no difference. I'm starting to lean towards a bad crank seal, injectors, or fuel pump causing a lean condition which is being picked up by the EGT sensor and causing the ECU to cut ignition.

Sled is 2012 800 with about 3000 miles. This is the first problem that I've had with the sled. Engine is stock with an SLP pipe and PCV with the SLP map.

Throttle safety switch! Mine (2011 Pro w/full Slp stage 3 and Rtk tech pistons)has done the same thing for three weeks, just like dropping a cylinder! Great compression(1st thing checked, matched preseason service with no drop). We changed every part we could think of with a donor sled. Still had no codes or change to ****ty running on the top. A shorter sit down rider, test rode it by chance and problem went away 8250 rpm extremely strong again, I would ride it and problem came back(every time). All we can think of is his throttle pull was different than mine. Swung by my dealer to pick up my new sled(2014 just purchased) and they put my 2011 on the wrench 22 throttle safety codes, throttle block wore out from standing and rolling sled to unstuck. Replaced and problem gone!

Miser

 

[tdbaugha]

Throttle safety switch! Mine (2011 Pro w/full Slp stage 3 and Rtk tech pistons)has done the same thing for three weeks, just like dropping a cylinder! Great compression(1st thing checked, matched preseason service with no drop). We changed every part we could think of with a donor sled. Still had no codes or change to ****ty running on the top. A shorter sit down rider, test rode it by chance and problem went away 8250 rpm extremely strong again, I would ride it and problem came back(every time). All we can think of is his throttle pull was different than mine. Swung by my dealer to pick up my new sled(2014 just purchased) and they put my 2011 on the wrench 22 throttle safety codes, throttle block wore out from standing and rolling sled to unstuck. Replaced and problem gone!

Miser

I'm running a billet throttle block with the TSS deleted.

Pulled the reeds last night. MAG side was pretty bad. Already ordered some. I'm pretty confident that is my issue.

 

[04proxr800]

Really bad reeds will give you a really low idle, 1500 cold and 1000 or less rpm once it warms up. Just had bad reeds in mine, took a while to figure out because they were new... aftermarket doesn't work...

 

[theshadowrider]

I'm running a billet throttle block with the TSS deleted.

Pulled the reeds last night. MAG side was pretty bad. Already ordered some. I'm pretty confident that is my issue.

Make sure to post how it runs!

 

[Scott]

Ran good today, right?

 

[tdbaugha]

Ran good today, right?

Negative.

I was supposed to get a new TPS last wednesday but it was lost in the mail so I never got it on for the weekend. Had a similar issue when I first built my sled and it was a "dead spot" in the TPS.

The reeds helped - ish. The sled runs way better now but still has that weird WOT, high temp, high load bog.

Friday I reinstalled my old TPS and noticed that my reference voltage was 5.03V. Service manual calls out 4.99 - 5.00V. I still think 5.03 is within spec per Polaris though. +/- 0.5 millivolts is way to precise for the electronic hardware on these sleds.

I also tried other plug caps and that obviously didn't help.

Hopefully UPS can figure out what the heck they're doing and get me my new TPS for the weekend! Supposed to be deep up here!