Is the spark arrestor clean?

 

It happened suddenly and was running perfectly before, but I'll check anyway.

 

Check the TPS adjustment.

 

I'll give that a try.

 

Three possible items:
1) Spark Arrestor
2) TPS Adjustment
3) Throttle Cable Adjustment

Check out the service manual for proper instructions....

 

clean the o2 senser.. I have a 2011 and could not get mine above 5200 rpms.

 

Fuel Pump...

 

fuel pump

 

Thanks guys. I'll check all that's been suggested as soon as it warms up a bit. Is there any way to check the fuel pump output without the Polaris gauge?

 

"...as soon as it warms up..." ?
Based on where you are that could be next June !!!

Keep us posted on what you do/don't find.

 

Most auto supply stores will loan you the adapters and gauge to check it. 39 PSI +/- 3 psi is what your looking for.

 

X3 on the fuel pump. Airtex E8335 is a replacement. Should be available at Oreilly Auto or othe chains, or Ebay.

 

Well, it warmed up enough to check out a few things but still no luck :sad:. Fuel pump delivers 39 psi; the filter is completely clean; I've drained the gas, added fresh plus a drying agent; cleaned all electrical connections. I also checked out the TPS - 0.70 volts at idle, 3.67v at WOT. I don't think the TPS adjustment has changed since it seems tight.

Does anybody have any suggestions on what to try next? Is there anyway to test the ECU?

 

You really need to do a static, not running, TPS adjustment. There is one other thing, the wires into the connector into the ECU have caused me problems on a 08'. Thought that was fixed in 09' and later with a much stronger setup. If it is the later setup it will have a very good connector set up. If not, then just the wiring harness going into the ECU are very visible. What happens is the harness weight pulls on the wires to the point they make bad connections to the pins in the ECU. Have had to remove the connector and work slack into the wire connections. First thing for me is to do a static check on the TPS.

If you think it is the ECU I have one never used. The ECU has to be programmed/flashed for your machine by the dealer.

 

The TPS test was done with the engine off but key on.

That's what I initially thought it was because last year I would occasionally have a similar problem and wiggling the ECU connection would solve it. Even after I cleaned the connection thoroughly it didn't help this time but I will definately check the connection again.

 

Was the 39 PSI at idle or wide open? It has to keep a consistent 39 psi. It is very possible it can do 39 psi at idle but not at WOT. We are talking pressure and plus volume.

 

I checked it stopped and idling. It stalled while idling before I could test it a WOT, however it still had 39#. I was by myself and didn't have a long enough hose on the gauge to see it from the cab. I'll check it again.

 

Have you checked compression? Just to rule out jumped timing and to check the plugs to see if both cyl are firing ok.

 

I rechecked the fuel pressure and it was a constant 39# even at WOT. Also rechecked ECU connection and it looked good. I decided to put it away until spring and limped it over to the storage shed ( still running like $h^t). I left it idling while I got the door to the shed open. When I went to move the RZR in it seemed to run normally, so I backed it up and went for a rip around the yard (I live on an acreage). It ran perfectly, wth! I don't know whether to be happy that it's running again or pi$$ed because I don't know what caused the problem. Whithout knowing what the problem was I'm scared it'll leave me stranded on the trail again.

 

are you using fuel with ethaol?

 

I'm not sure, it may have up to 10% ethanol, but the problem occurred suddenly and disappeared just as suddenly.

 

I don't know then , only problem I have had was I got gas from a gas station and the rzr ran very bad I tested the fuel and it had about 30-40 ethanol, it will settle on the bottom of the tank of the gas station, any station that dose not sale a lot of fuel can cause you to can get fuel with a much higher ethanol ratio. Causing hard starts when hot running rough

 

Does it sound/feel like a cylinder is missing?

I had an issue with the spark plug boot arcing to where they plug in behind the seat which caused one cylinder to not fire and it to not rev/run well at all. I had to mummify it in electrical tape for a quick fix but now have put dielectric grease on it as well and hope it's a more permanent fix. I'll get new wires eventually.

I found it out the hard way and touched the boots while it was running and got the electrical pulse sent to me! That shouldn't happen on a properly sealed boot.

 

I inspected the caps and they looked good. I think sometimes both cylinders were cutting out, sometimes only one. It is running fine now. Come spring we'll soak down all electrical connections and see if we can find the problem.

 

Hello, mind did that same thing 2013 rzrs, try this once you warm it up good put it in drive keep patting the accelerator to the floor but dont hold it to the floor it will clear right up. I hope this will help you out. is your check engine light on to mind was two.

 

/09 RZR 800 will start & idle but will only rev up if you contiuously pump the accelerator peddle. If you hold the peddle steady the engine dies. I've cleaned all the electronic connections related to the engine but nothing helps. Anyone got any ideas?

Hello, mind did that same thing 2013 rzrs, try this once you warm it up good put it in drive keep patting the accelerator to the floor but dont hold it to the floor it will clear right up. I hope this will help you out. is your check engine light on to mind was two.

If i was to try that when mine was running bad it would accelerate a bit but wouldn't clear up.

 

/09 RZR 800 will start & idle but will only rev up if you contiuously pump the accelerator peddle. If you hold the peddle steady the engine dies. I've cleaned all the electronic connections related to the engine but nothing helps. Anyone got any ideas?

Hello, mind did that same thing 2013 rzrs, try this once you warm it up good put it in drive keep patting the accelerator to the floor but dont hold it to the floor it will clear right up. I hope this will help you out. is your check engine light on to mind was two.

If i was to try that when mine was running bad it would accelerate a bit but wouldn't clear up.

Ok did you try changing the spark plug?

 

The plug boots have a resistor in them, unscrew the wire from the boot and check them with an ohm meter, should read 5000 Ohms roughly. Also check that your ignition coil is grounded well, mounting bolts tight,etc.

 

It turned out that I had gotten water in the gas. (Apparently the gas cap wasn't screwed on tightly when I went through some water.) When I was putting it away for the winter it suddenly started running normally and has been running fine ever since.

 

Check the gas tank vent line too. cost me a fuel pump i got so much mud and water into the tank via that poorly located vent line!:sad:

 

Hard water or soft?

 

That's funny right there...

 

it was still soft, lol

 

Did yours ever send a check engine code? Mine will start and idle fine but won't rev over 4300 an bogs down. I'm at my wits end on how to fix it. It sends a crank sensor code but everyone including dealer tells me that's not the problem