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Discussion Starter · #1 ·
So with a new full size here getting ready for its new life, one of the others needs to go.

I have a 2018 that for a couple years now has had an issue running cold. It’ll run smooth and then just shutoff suddenly. It will restart and might stay running, maybe not. Might run 1 min might run 5 or 10. Once to operating temp it stays running. I’ve checked for codes, checked for rubbed wiring checked valve lash and replaced the fuel pump twice.
I hate throwing more parts at it without a direction, but I’m almost ready to put a complete throttle body on it.

Any ideas?
 

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Hey Adam, if it wasn't for the fact that it is a 2018 and " Once to operating temp it stays running. ", I would say that it might be a faulty ignition switch or a bad/dirty connection at the THROTTLE PEDAL but you know how fickle a Ranger can be sometimes. As far as the throttle body goes, I had to replace my 700 TB with 1500 hours on it with a new one as I could not get it stabilized. Runs perfectly with the new one .Although the 700 and 570 TB's are so different, I am convinced now they have a usable life span . Yours probably has 3000 hours or more as I know you guys really roam the landscape there on the ranch.

Happy Thanksgiving to you and the family !
 
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I was reading where some earlier model 570's (2015 +) were getting a "cold restart flash" done to the ECU compliments of POCO for this problem. Engine starting rotation speed in the cold was also a big factor. A clean TMAP sensor and a unblemished TMAP harness was also a plus. NO ethanol fuel is always a must not have.. Maybe a 900 engine upgrade or switch back to them wild ponies ? o_O
 

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Maybe a 900 engine upgrade or switch back to them wild ponies ? o_O
With no intent of stealing this thread, can a 900 engine be installed in place of the 570 on the 2015 570XP models?
 

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With no intent of stealing this thread, can a 900 engine be installed in place of the 570 on the 2015 570XP models?
The main frame of the 2015 570 & 900 are the same so that would follow the 'anything is possible' scenario depending on how bad you want it and how much you are willing to spend to make the swap :).
 
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Discussion Starter · #8 ·
I can get in touch with my Polaris tech tomorrow or next week and see if there is a reflash we can try. Might try taking the throttlebody off and giving it a thorough cleaning again. It’s just a really weird deal. It always starts up when cold, just likes to intermittently die, until it warms up. Acts like either an idle air control or TPS issue to me. Although
 

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The electronic throttle pedals have a history but that does not explain why after warm up it starts normally . A CPS problem will kill the engine intermittently but once again would not explain the temp variable.
 
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‘17 Ranger 570 Midsize
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the reason I asked, higher octane gas does not like cold weather starts.
I think that's only for the high HP engines. I've only ever ran Premium in my 2017 570 Midsize, and it starts reliably at all temperatures. Well, down to negatives in F. Sure, I may waste some money, but I don't use that many gallons a year, and I can buy Premium without Ethanol. I find it simpler and better for all my other engines even though I also use Stabil at times. I also keep my Ranger on a trickle charger to make sure the battery is at full strength.
 

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Has nothing to do with HP. If I remember right and not being a chemist, higher octane takes more heat to burn, a lot of people start having trouble when the weather turns colder running 91. I'm not here to argue or promote ethanol, I've fixed a lot of stuff it's screwed up, but have run it in 2 different rangers over 10years with no issues, main problems seems to be older stuff, pretty much everything today is designed to run 87/10. Now, on the 570's, at least the ones I've been around, always thought they seem to crank over slower.
 

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I believe the difference, in lay terms, between high octane and lower octane (regular) gasoline is the rate of burn or flame propagation. Fast flame burn rate in high compression engines causes pre-ignition and possibly detonation which causes engine damage. The slower burn rate of high octane fuel eliminates this.
Of course this is a super simplified explanation; RPM, combustion chamber temperature, combustion chamber design, spark plug heat range, carbon build up, ignition timing, cam lobe overlap and lobe separation angle all play a part in how much pressure the cylinder really sees. In real day to day terms the use of high test (high octane) fuel in lower compression engines (those designed to run on regular fuel) really isn't noticeable. I suppose in extremely cold temperatures starting may be harder but the reality is that the vaporization rate of the fuel probably plays a larger role in hard starting in cold temps than octane number.
For the record, I use 90 or 93 octane non ethanol regularly in my 570 and have no trouble starting the engine at temperatures below freezing and into the high teens (F). I have had incidents of starting and stalling with a restart required at low temps a few times, but after the restart it continues to run.
 

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Has nothing to do with HP.... Now, on the 570's, at least the ones I've been around, always thought they seem to crank over slower.
I have a 570. Pyromedic has a 570. Higher octane is no issues for these two engines in spite of that theory.

OP has a 570. Unless you can point to a 570 that has issues with high octane in cold weather, I don't think that's OPs issue. But, maybe OP will post whether he is using high octane or not. ;)
 

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I have a 570. Pyromedic has a 570. Higher octane is no issues for these two engines in spite of that theory.

OP has a 570. Unless you can point to a 570 that has issues with high octane in cold weather, I don't think that's OPs issue. But, maybe OP will post whether he is using high octane or not. ;)

It was actually Adam the op.... a year or so ago. Who posted about the 570 having issues with higher octane in cold weather. Was either in his fleet or neighboring farms with 570's. The switch to 87 cured the hard cold starts.

I'm sure it depends on the year and how the ecu's fuel and timing mapping is set up.
 
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It was actually Adam the op.... a year or so ago. Who posted about the 570 having issues with higher octane in cold weather. Was either in his fleet or neighboring farms with 570's. The switch to 87 cured the hard cold starts.

I'm sure it depends on the year and how the ecu's fuel and timing mapping is set up.
My point is that it's not a generic octane issue for that engine. That particular Ranger 570 has other issues. Quite the puzzle. I don't know if there are settings that dealers do or are supposed to do. Mine is a 2017, btw.

I guess that means he's not using high octane fuel in any case.

Fwiw, the hardest thing my Ranger does is haul firewood, dirt, or snowplowing. I don't trail ride it, and I'm in L almost all of the time. The only issue I've had is getting air into the coolant system. Mine is stock with the exception of a MMA lift.
 

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Something to consider that has more to do with temperature than octane is that in some parts of the country they have summer and winter blend gasoline for emissions purposes. Summer blend gasoline has additives that reduce vaporization becasue gasoline vaporizes more easily in warm temperatures. Therefore if a summer blend fuel is being used in cold temperatures hard cold starting may be the result.
See more info here: The Difference Between Summer-Blend and Winter-Blend Gasoline
 

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Discussion Starter · #18 ·
I have a 570. Pyromedic has a 570. Higher octane is no issues for these two engines in spite of that theory.

OP has a 570. Unless you can point to a 570 that has issues with high octane in cold weather, I don't think that's OPs issue. But, maybe OP will post whether he is using high octane or not. ;)
Yes, actually, high-octane fuel is a poison to cold start ability in very cold temperatures. It was an issue on the old Ranger 800s, but a much bigger issue on the 570s and 900s.

every single one of our 5 570 machines will not start well in cold-weather (below zero) on 91 octane fuel. Put about two or 3 gallons of 85 octane in it and they will start at any temperature. my neighbor had the same issue with his ranger 900 thought I was blowing smoke at him when I told him to put some 85 in it. Now he keeps a can of it in his garage every time the weather gets down below 10°. . it’s no theory, it’s proven fact around here that you don’t run high ethanol fuel in the winter time even my local dealer has been pushing that fact as well.

However, octane level has nothing to do with my cold start problem
 
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