PRC Polaris Ranger Club banner
1 - 20 of 28 Posts

·
Registered
Joined
·
242 Posts
Discussion Starter · #1 · (Edited)
I got a 2012 800 Crew a few weeks back. Had to do a bunch of repairs on it like wheel bearings, CV axles, brake pads... that kind of stuff. Previous owner had let it sit for a couple years because he said the trans was gone. I was able to get it started and drive it on the trailer. Finally get everything back together and drove it around for maybe 5 miles. Turned it off and tried to start later and it will not start. Engine turns over just fine, but it will not start.
Sometimes it will hit a little, but that is all I get. The error code that it is showing is 636-2 (crankshaft position sensor).
Here is what I have done.
1.Per the service manual I checked the resistance of the CPS sensor. Reading is 600 Ohms between yellow and white wire. Manual gives it to be 560 +/- 10% (504 to 616). I assume the sensor is good.
2. The CPS wire is a twisted pair black and white wire with a brown shield wire going between the CPS connector and the ECM so it is easy to find the wire in the loom at the ECM plug. I checked the black and white wire for continuity between the CPS plug and back probing the ECM plug (unplugged from ECM). Reading for both was 0.1- 0.2 ohm. No broken wire.
3, Checked for short between black and white wire and it was open. No short.
4. Pulled off fuel line on the rail. When I turn on the key, the fuel pump cycles for a few seconds. Got good fuel flow, but did not check the pressure. When I release the fuel line on the rail, there is pressure there because a small amount of fuel squirts out.
5. I pulled out plug and spun over engine. Plug is firing good.

Only other thing I have thought it might be could be is engine timing. Maybe the flywheel has sheared the flywheel key and it is no longer in correct time.

Question:
1. If CPS sensor passes Ohm test, what is the chance that it is actually bad?
2. When the engine is turning over, if I change the display to show RPM, it shows the RPM as it is turning over. Does this alone not indicate the that CPS sensor and wiring are good?
3. What am I missing?

Thanks

Speedometer Trip computer Odometer Motor vehicle Automotive lighting
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #2 · (Edited)
Something I did today was remove the air filter and sprayed some gas into the air intake. Now when I spin it over it, it will start and run. Runs for a few seconds until all the gas is gone, then dies. So that tells me I have good fire and probably rules out timing. Question is why is it not getting fuel?
I then put a fuel pressure gauge on it and got 43psi maximum. The service manual says it should be 56-60 45 psi. I still think that it should run on 43psi... but maybe not.

I pulled out the fuel injectors and held them in the fuel rail as my buddy tried to start it. I could see a fine mist of fuel coming out of the injectors. Just not sure if it would be enough for it to run, but I thought that it would be.

I no longer have a CEL. It went off when it ran for a few seconds.

So now I am down to either a set of injectors or a fuel pump. I really don't think it would be the injectors, because what is the chance that both of them would fail at the same time? .... Or maybe it had been running on only one injector all along and the one finally gave out. I really don't think that is the case because it was running pretty good before it started acting up. I had already had it to 48MPH. Don't think it would do that on just one injector.

Any suggestions?
 

·
Registered
Joined
·
2,095 Posts
I don't believe they raised the fuel pressure on the 800 to 58 psi until 2013. Pretty sure your in spec for a 2012
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #4 ·
You could be right. I only have a SM for a 2013 800. I thought they were the same, but could be wrong. If you have a SM for a 2012 800 can you verify the fuel pressure value?
 

·
Registered
Joined
·
2,095 Posts
You could be right. I only have a SM for a 2013 800. I thought they were the same, but could be wrong. If you have a SM for a 2012 800 can you verify the fuel pressure value?
I'm 99% sure. They would reflash the ecu on the 2012 if it was having vapor lock issues if you complained and updatet he pump. But didn't bump the pressure to 58 until 2013.
 
  • Like
Reactions: RangerRider_1

·
Registered
Joined
·
242 Posts
Discussion Starter · #6 · (Edited)
If that's the case then I have good fuel pressure and the engine runs when I manually spray gas into the intake. I am back to the injectors being the issue then. Not sure what else it could be.

I verified it from the 2012 800 service manual. Fuel pressure should be 43-47 psi.

Rectangle Font Electric blue Logo Brand
 

·
Registered
Joined
·
2,095 Posts
Does the fuel pressure hold at 43 with just a cycle of the key? Or does it bleed off quickly?
 

·
Registered
Joined
·
2,095 Posts
Will it hold without cranking? Just turn the key on. It should jump to spec and hold. Don't crank it over.
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #15 ·
Did you check the vent line on your tank and the intake boot?
No. I guess your thinking that the vent might be clogged and causing a vacuum inside the tank as fuel goes out? I'll check that, but don't think that is the case.

What should I be looking for on the intake boot? Is this the intake boot?

Font Automotive lighting Automotive exterior Auto part Engineering
 

·
Registered
Joined
·
1 Posts
Did you inspect the fuel pump? Pull it out and inspect the filter. Aftermarket pumps are affordable and easy to replace.
My 5-year-old RZR wouldn't start and the fitter sock on the intake pump line was shredded and disintegrated. Choking the fuel. Removed the pump, drained the tank, and wiped it clean and dry. Vacuumed out the debris and installed and new pump. You can rebuild yours or replace it. Here's a link Product Result
Good luck!

Steve
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #17 ·
Did you inspect the fuel pump? Pull it out and inspect the filter. Aftermarket pumps are affordable and easy to replace.
.
.
.
Good luck!

Steve
Yes. I have pulled out the pump and inspected the sock. Also cleaned the tank and put in new fuel. All that is good..
I have good fuel flow from the pump when I disconnect the line from the fuel rail. Also checked the fuel pressure and it is 43psi.
 

·
Registered
Joined
·
242 Posts
Discussion Starter · #18 ·
Update
Replaced both injectors today and it still won't run. I have got it to start at times and roughly idle but as soon as I try to give it gas, it dies.
Tried again to make it run by spraying gas into the intake and it will run strong doing this, So this should rule out timing and fire.
Looked at intake boot and did not see anything wrong with it.
Could it be the TPS even though I have no codes?
Check engine light is off. Engine spins at 400 rpm while I am cranking on it. Most times it won't start. If it does, it will only idle. I give it gas it dies.

Suggestions?
 

·
Registered
Joined
·
2,095 Posts
No. I guess your thinking that the vent might be clogged and causing a vacuum inside the tank as fuel goes out? I'll check that, but don't think that is the case.

What should I be looking for on the intake boot? Is this the intake boot?

View attachment 143795
Part 7 is what you want to check. Will usually crack along the bottom side.
Font Auto part Art Fashion accessory Pattern
Font Auto part Art Fashion accessory Pattern
 
1 - 20 of 28 Posts
Top