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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

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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?
 

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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?
 

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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.

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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?

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Discussion Starter · #17 ·
Did you inspect the fuel pump? Pull it out and inspect the filter. Aftermarket pumps are affordable and easy to replace.
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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.
 

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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?
 

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Discussion Starter · #22 ·
Yes make sure it is not clogged up. And on the throttle body intake boot look to see if it is cracked/busted anywhere

Did you spray carburetor cleaner around the intake boot when it was running and check the frame where the vent line goes into because the line may not be stopped up but the frame tube may be.
Did not spray cleaner around intake.... but I will try that tomorrow to see if changes anything.

I did pull the vent line out of the frame and I am able to blow air thru it. I don't think its clogged. Left the vent hose out of the frame when I was trying to get it to start. Didnt help
 

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Discussion Starter · #23 · (Edited)
Checked compression today just to see what it was. 110 on L side, 150 on R side.

I am still going down the path that this is a "fuel" issue because if I put fuel into the intake the motor runs. I checked the fuel pressure and replaced both Injectors. IF the injectors were not firing, then fuel would not be getting into the cylinder. To test this, I unplugged the injector at the harness and checked voltage between red/blue wire and ground. This reads 12.5V as I would expect. Then checked ohms between black wire pin and ECM pin 5. Reads .2 ohm, so no break in the wire. Next I put my test light between red/blue pin and black pin on the harness. When I spin the motor, the test light strobes. This tells me the ecm is pulsing the signal to fire the injector. IF fuel is at the injector and it fires, it should go into the cylinder and burn.
 

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Discussion Starter · #24 ·
Update
I tested the new injectors in the engine by manually pulsing 12v to them. The engine ran doing this. It was rough, but it was running. With this, I was thinking that "something" was keeping the injectors from firing. So I pulled out all the wiring in the loom for the TPS, IAC and T-MAP sensor all the way back to the main harness. Where the wire had touched the inside of the loom, it rubbed thru the wire insulation. Several wires in this loom looked like a saw had been ran across them. I separated out the wires and just let them lay on top of the engine.. Now the engine starts and runs. :)

Now I just need to clean up the wiring issues. Polaris really needs to do a better job of protecting the wires inside the loom.
 

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Discussion Starter · #28 · (Edited)
Now I just need to clean up the wiring issues. Polaris really needs to do a better job of protecting the wires inside the loom.
Update:
I solved my wiring issues on the three sensors (TPS, IAC, T-MAP) by cutting out the old wires and splicing in new ones. Keys to making this work is:
1. Use the same gauge wire as OEM. They use 0.5 mm, which is the same as 22ga. Make the repair the same length as the original.
2. Solder the joints. Do a good job soldering them with just the right amount of heat/solder.
3. Use shrinkwrap to cover and wrap good before putting back in loom.

Many ppl say you can't do this and you have to replace the harness and or plugs. It can work if the plug itself is not also damaged. After I made this repair, I still had the 102 error. Since I knew the wiring was good I ordered a new T-MAP sensor. After I replaced that sensor, no more CEL and the motor has not had an issue since. Starts with just a bump of the key and runs great.

Thanks
 
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