Low idle, Low RPM surge 19-20 800 Axys

[jbrevsup]

OK,very odd problem here. I know of at least 4 other 2019-2020 800 Axys that are during this! When all of these machines got about 400 miles on them they started to surge at low rpms and have a low idle. Some of these machines are completely stock, some have just a can, two have SLP pipe. Our parking lot is at 9000ft. the highest area is about 10500 but most of the riding is between 9500-10000. When the sleds are started in morning they run flawless. We have to run out 7-10 miles of trail to start the play time so good heat soak in motor before playtime begins. After playing for a bit shut the motor off and start the sled and it will have a surge between 4000-5000rpm and low idle(around 1500rpm). As the day goes on this gets progressively worse till at the end of the day the machine will barely idle and the surge is like it is cutting out. As long as the you are on the throttle above about 5500rpm it runs fine. Many trips to the dealer for throttle cable adjustment and TPS check. No codes It seems that when the machine fully cools off whatever the problem is fixes itself. Makes me think it is a electrical circuit getting overheated and creating some more resistance causing the ECM to compensate for this. I have also suggested to the dealer that it might have something to do with the coolant bypass system on these sleds. I have a 2017 800 with SLP pipe with the resistor in for O2 sensor,IndyDan RideCool head for 9kto12k and runs flawless after 2200 miles. Both machines run at about 95-100 degrees when in the powder. I know SLP has three different options for a Stage 3 kit for the different years 16-17, just 2018, and 19-20. Makes me think the mapping for the ECM is different for all these years.Any suggestions?

 

[Sheetmetalfab]

Silber turbos has a different map for those 3 different year groups. all installed with the same turbo kit.

My 2016 runs cleaner and idles better than my brothers 2018. ??‍ (My 16 Uses more fuel for sure though)

My only thought would be that you might try Silber turbo’s N/A reflash.......... (assuming you are out of warranty)

 

[mtncat1]

my 19 with a side kick surges a little at 4k to 5k but its intermittent and i rarely ride in that range ,always starts great though .
my friend has a 17 that has a similar surge at low rpm but runs poor on restarts warm and sometimes stalls , it's been in and out of the shop for the past month , to day they found low compression warm . we will see if a new top end fixes it .

 

[diamonddave]

Have you tried running without the pipe temp resistor? If not, I’d try that first.

 

[jbrevsup]

Has anyone heard of the power valve servo motor cables needing adjustment?

 

[edgey]

My 20 800 does this too, surges and dies when trying to reverse. PITA!!!

 

[kidwoo]

Bumping this up. My 800 went through some surging when it was younger but then quit doing it. It also had some issues that I was able to tie back to the polaris tether.

However.....I do have a low idle (1550rpms). Anybody ever figure out what's up?

 

[jbrevsup]

Sorry I didnt update this sooner. Turned out to be fuel injectors! Put new ones in last fall and rips again!!

 

[longvalley]

i had same problem on my 20 800 pro rmk. all stock except ggb trail can. dealer did all diagnostics and said everything ok. read this post and decided to try new injectors. rode this weekend for first time since replacement and seems to be cured

 

[RMK900Tractor]

Does anybody know the part number for the injector? Think they are all made by Bosch so would prefer to save some money and buy at the local auto part store vs. Polaris dealer.

 

[Jpkos]

OK,very odd problem here. I know of at least 4 other 2019-2020 800 Axys that are during this! When all of these machines got about 400 miles on them they started to surge at low rpms and have a low idle. Some of these machines are completely stock, some have just a can, two have SLP pipe. Our parking lot is at 9000ft. the highest area is about 10500 but most of the riding is between 9500-10000. When the sleds are started in morning they run flawless. We have to run out 7-10 miles of trail to start the play time so good heat soak in motor before playtime begins. After playing for a bit shut the motor off and start the sled and it will have a surge between 4000-5000rpm and low idle(around 1500rpm). As the day goes on this gets progressively worse till at the end of the day the machine will barely idle and the surge is like it is cutting out. As long as the you are on the throttle above about 5500rpm it runs fine. Many trips to the dealer for throttle cable adjustment and TPS check. No codes It seems that when the machine fully cools off whatever the problem is fixes itself. Makes me think it is a electrical circuit getting overheated and creating some more resistance causing the ECM to compensate for this. I have also suggested to the dealer that it might have something to do with the coolant bypass system on these sleds. I have a 2017 800 with SLP pipe with the resistor in for O2 sensor,IndyDan RideCool head for 9kto12k and runs flawless after 2200 miles. Both machines run at about 95-100 degrees when in the powder. I know SLP has three different options for a Stage 3 kit for the different years 16-17, just 2018, and 19-20. Makes me think the mapping for the ECM is different for all these years.Any suggestions?

Can I contact you or chat about the details? I have a 2020 800 that is acting like what you have described in your post. Not sure what to do next.

 

[jbrevsup]

OK my 19' 800 has about 2600mi on it now. I put the new injectors in it at about 1100mi and it has run good since then. I always let it warm up to 90 degrees before I move it. Whether first start in the morning or after taking a break. My thermostat went bad earlier this year (stuck open) so it was really tough to keep heat in the motor. Thats all better now! I also put about 8oz of seafoam in it about every third or forth ride. To my knowledge everyone that I knew that replaced their injectors hasn't had any other issues either. The part # for the injectors for mine is 4014715, you will have to get the o-rings also. I would say replacing the injectors is not easy. Kinda time consuming and the o-rings that go on the tips are a pain. But if you have decent mechanical skills you can do it.

 

[Jpkos]

thanks for the follow-up. did your lights go off and on when it would cut out? mine does and the mechanics think it is electrical...maybe?

 

[longvalley]

My injector replacement fix lasted approx. 600 miles and now same problem is back . Starts fine . but engine surges at low rpm after sled is warm. Gets worse as day goes on especially if you stop during a ride and then restart in 10-15 minutes . mechanic is thinking to try tmap sensor or fuel pump next.

 

[meyerx]

Hi,
I have a 2020 RMK 800 with what sounds like the same low rpm surging problem.
My sled symptoms are:
-a cold start does NOT result in an elevated rpm, as it should. So i have to babysit the sled to keep it running during warm-up. Not sure what's going on there.....annoying.
-then the sled surges with off-idle rpm's at and below 5500 rpms.
-anything above 5500 rpms seems smooth and totally fine. It pulls great.

The tps has been dealer checked and in spec. No codes. I just pulled and cleaned the exhaust valves. No impact.

Is the agreement an injector issue? It seems longvalley's issue returned after injector replacement. Something else? Any other thoughts??
Thanks!

 

[curranl]

Very interested in everyone’s experiences here. I bought a ‘19 RMK and took it out for the first time today. After a warm restart, it would idle at 1300-1400 and sometimes stall. Other times it would idle at 1850-1900. I also felt the surge at around 5k but it wasn’t consistent.

 

[Gunk]

I'm having the same problems, low idle, 1300 rpm, ran great at top end, heading back from breakfast and just died like it was out of fuel, towed it back, filled it up and can't get it to run again for more than a few minutes, it has a turbo but never had any problems

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[meyerx]

I recorded the motor pulsing at low-rpms:

New video by Alex Meyer

photos.app.goo.gl

Riding slower makes it even more abrupt.
Once you hit mid-throttle (around 5500rpm) and beyond, it pulls smooth and strong, zero issues...

 

[Gunk]

I finally worked on my sled, reset TPS , fixed stator wiring, decided to check compression, 80 in PTO, 0 in other, still ran just didn't idle, new top end on the way hopefully that's the fix


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[meyerx]

Same fix for the thread's originally stated surging problem at low-rpms. Injector change seems to have addressed the problem. Fingers crossed that it sticks
for the life of the sled.