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Just want to see if I can get some more input. A while back I explained to my mechanic that when my Ranger is hot it idles real rough on start up. He explained to me to just rev it up and it will idle fine. He was exactly correct. He said to drive it this way until the part went out. He said it was the "rev limiter" (I believe) and it was pretty expensive, I have done that for a while. Now when its hot and I try to start, it wont start until it cools off just a little. Then it starts just fine....rev it up one time and she's ready to go, but Ive had to do this 2 or three times this week, with deer season quickly approaching I dont want to get stuck in the woods.

Could anyone give me their opinion on this issue, and if this is the "rev limiter" going bad is the "rev limiter and ECU the same thing??? I have looked at parts on the micro fiche and cant find a part called the "rev Limiter"

Thanks everyone for your expertise. :D
 

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The ECU is what limits rpm's and it is not "going bad". It's VERY rare for an ECU to fail, plus they simply work or they don't and will not typically show a sign if it is getting ready to fail.

Several of the 2011 and 2012 800's have had some heat issues and my guess is that your problem is that it's vapor locking when it's hot.

Another possibility is that the fuel pump is geting weak. Sometimes a weak pump won't show itself until it gets hot. Try getting the machine hot enough to duplicate the problem and then check your fuel pressure.
 

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My 2012 6X6 did that and I found that by letting it idle untill the temp drops to 194 and the fan turns off that it was no longer an issue.
 

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Buy some good quality high heat resistant Taylor brand thermo fiberglass sleeve line insulation. I got mine at summit racing, insulate the fuel line from the tank to the motor. This prevents the exhaust heat from causing the fuel line to heat up and possibly cause vapor lock or fuel boil.



 

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If your mechanic is telling you that your rev limiter is going bad then I would highly suggest you find a new mechanic. Like commanderjjones said, the rev limiter is controled electronically by the ecm. As for the hard starting when hot is seems that most have had good luck not shutting the engine down if the temp is high enough that the radiator fan is on. Wait until the engine cools enough that the fan shuts off before shutting down and it should start a little easier.
 

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To help prove the fuel getting too hot and causing the system to vapor lock, the next time this happens, take some ice and rub the fuel line down real good. Chances are that it will crank right up. :D Most likely it's high exhaust temps causing the problem and if your fuel pump gets a little weak it lets the problem worsen. The more pressure the fuel system has, the higher the temperature needed to make the fuel "boil".

There are a lot of post on here about adding insulation, fans, and richening the fuel mix to help cool down high under seat temps. Adding a $20 atwood marine fan under the seat seems to be a good bandaid also. It's low cost, water proof, and it doesn't draw many amps to operate.
 

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Hello PRC. First time poster long time reader.
On my 2011 800xp I was having hot start issues and rough idle when hot. The problem seemed to get worse as time went on until I starting getting stranded places until the motor cooled down. I would watch my temp gauge prior to the rough idle and hard start condition and everything seemed fine. Engine would heat up to about 204. Fan would kick on and the temp would lower to about 179 and repeat. This led me to believe it must be a fuel or ignition problem. After ruling out ignition it was on to fuel. While running the ranger it began to run rough and stalled at idle. It would not start no matter what I tried. So while messing around with the engine I removed the fuel line reserve off the end of the fuel rail and noticed a huge amount of pressure and fuel release from the fuel rail. This should not happen as the ranger ecu actually runs the fuel pump in reverse to clear the fuel line about 5 seconds after the ignition looses power.
So I had unwanted pressure hold fuel in my fuel rail and this was the cause of the poor performance from the ranger. Adding this to the fact that the problem only happens after the engine has been running for a while ment the two conditions were tied together. I did as much research as I could and learnt that if there isn’t enough air around gas won’t ignite. The fuel line coming from the ranger is routed right over the exhaust pipe. And the heat from the exhaust is actually able to boil the gas in the fuel line causing it to expand and vapour lock the fuel line.
A couple fixes for this could be to reroute the fuel line away from the exhaust or upgrade the fuel pump to be able to overcome the vapour lock. I learnt that I. 2013 Polaris themselves addressed this known issue ( that they won’t seem to admit) but upgrading the fuel pump from a 42 psi output pump to a 58psi pump. So I decided to do the same as Polaris. I also read and even the pump I bought recommended a tuner or ecu flash to adjust the fuel ratio being delivered to the engine. So I bought a tuner and upgraded fuel pump and installed them both. Keep the tuner at stock settings and was going to see how it ran and what adjustments might be needed.
All of a sudden all my problems went away. Engine idles perfectly regardless of temp and time off year and length of use. Never have an issue starting when hot and feel like I’ve even got a small performance increase. The engine seemed to take way longer to heat up and runs cooler and smoother than ever.
Long story short. I think overtime the stock pump looses its ability to maintain its 46psi output and even begins to create a lean running condition. This in turn causes even more heat and causes the vapour lock which the stock pump can not overcome. i still am running the ecu at stock levels even though I have the tuner.
if you are having this issue get the 58 psi fuel pump and go from there. Made me love my ranger again and restored my confidence to take it places withoutgetting stranded.
 

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My 2011 has done this since it was new. Do you have a part number for the 58psi pump?
 

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Just fyi...........it is the REGULATOR that gives you 58 psi. The pumps put out waaaaay more than that. The catch is you have to have the ECU reflashed at the stealers to make it work........
 

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Had the dreaded 800 heatsoak vapor lock, engine would only turn over and must wait several minutes to restart. Stealers looked at me crosseyed about 58psi and reflash. Dropped in new complete one piece pump assy 42psi, heavy insulated the fuel line from tank to rail, this might be enough, also did fans for extra. No more vapor lock
 

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My 2011 has done this since it was new. Do you have a part number for the 58psi pump?
.
Just fyi...........it is the REGULATOR that gives you 58 psi. The pumps put out waaaaay more than that. The catch is you have to have the ECU reflashed at the stealers to make it work........
If you have a properly functioning pump this is true. The plastic vien and impeller assembly inside these poorly constructed pumps wear significantly allowing for loss in pressure and consistency. There is also a non serviceable micron screen inside the pump that gets clogged as well.

All the research I did points to a ecu reflash being required as well. However I am currently runninga 58 psi regulator on a brand new pump and have not done the reflash. Bike is running better than ever. Don’t know what to say.
 

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"Bike is running better than ever. Don’t know what to say. "

Your "bike" will probably run ok but a Ranger will run rich without the reflash.
 

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"Bike is running better than ever. Don’t know what to say. "

Your "bike" will probably run ok but a Ranger will run rich without the reflash.
My “bike” is a ranger lol. Sometimes people use slang terms such as bike, quad,rig, buggy, etc. Sounds like your the expert caveman so whatever you say must be true.
 

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My “bike” is a ranger lol. Sometimes people use slang terms such as bike, quad,rig, buggy, etc. Sounds like your the expert caveman so whatever you say must be true.
Agreed ..........bikes are kids...
 

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I’m running the pump below. With the 58psi regulator. Have about 500 miles on it now and couldn’t be happier. I’ve read numerous times a ecu flash or tuner is required to compensate the injector timing for an increase in fuel pressure. I hope I don’t give you poor advice my in my experience it hasn’t been necessary.
HFP-396-U4 Fuel Pump with Strainer, Regulator and Tank Seal Replacement for Polaris Ranger 499/500/1000 XP PS EFI (2013-2018) Replaces 2204852, 2521307, 2521091, 2204946 https://www.amazon.com/dp/B015PBVDJ0/ref=cm_sw_r_cp_api_i_YZnsEb23BJ6HS
 

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I’m running the pump below. With the 58psi regulator. Have about 500 miles on it now and couldn’t be happier. I’ve read numerous times a ecu flash or tuner is required to compensate the injector timing for an increase in fuel pressure. I hope I don’t give you poor advice my in my experience it hasn’t been necessary.
HFP-396-U4 Fuel Pump with Strainer, Regulator and Tank Seal Replacement for Polaris Ranger 499/500/1000 XP PS EFI (2013-2018) Replaces 2204852, 2521307, 2521091, 2204946 https://www.amazon.com/dp/B015PBVDJ0/ref=cm_sw_r_cp_api_i_YZnsEb23BJ6HS
I’m running the pump below. With the 58psi regulator. Have about 500 miles on it now and couldn’t be happier. I’ve read numerous times a ecu flash or tuner is required to compensate the injector timing for an increase in fuel pressure. I hope I don’t give you poor advice my in my experience it hasn’t been necessary.
HFP-396-U4 Fuel Pump with Strainer, Regulator and Tank Seal Replacement for Polaris Ranger 499/500/1000 XP PS EFI (2013-2018) Replaces 2204852, 2521307, 2521091, 2204946 https://www.amazon.com/dp/B015PBVDJ0/ref=cm_sw_r_cp_api_i_YZnsEb23BJ6HS
The initial reason for the 58 psi regulator was to help curb vapor lock on HOT restart by increasing the injector duration on start up with the ECU flash. Half azzing it will probably work ........until it doesn't when it gets HOT enough. The pump assembly I left the link for is for 2010 and older 700/800 Rangers just so there is no confusion created with the later link on the 2011 800 58 psi which is NOT the proper application for the 2010 800.
 
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