Need some HELP - suggestions welcome on what to look at next.
Have an 08 Dragon with an 860 Carls in it. It was due for a new top end so I pulled the top end, put new Carls (Wiseco) pistons and rings in it along with new wristpin bearings and all gaskets of course. Reassembled everything, started it up, idles fine but I was getting a 7-blink code which is a cylinder fuel injector fault. Those injectors are not used at idle. Loaded it up on the trailer and took it in to the local Polaris dealer who hooked it up to digital wrench to figure out which injector was the issue, it read the pto side cylinder injector was at fault. Only other notable thing was the TPS was off a little, but it has always run fine.
So bring it home, chase the wiring / remove some electrical tape and rubberized moulding, hook up ohmmeter, and find there is an intermittent splice – the injectors had been changed out and spliced and the splice was a crappy job. Fixed it, measured with ohmmeter again, wiggled wires all around, no more intermittent connection. 12 ohms constant. So I figure it is fixed and ready to go.
So I put it back together again, start it up and now it acts like it is running on one cylinder, idled but boggy and would not pick up speed and then died. Realizing the injector wiring I just fixed was for the cylinder injector which does not affect idle... strange. One side of y-pipe was warmer than the other.
Now it will not restart at all. Good compression, nothing abnormal there. Here is what I have tried, one step at a time (I am giving summaries but the sled was basically attempted to be started at every stage):
- Spark plugs out and grounded – good sparks
- Put fuel into cylinders through plug holes, replace plugs - it fires right up and then dies when the fuel runs out.
- Fuel pump pressure tested – seemed low, so...
- replaced fuel pump with a loaner used one from friend.
- replaced fuel filter with new SPI filter
- checked fuel pressure – same as with the old pump
- checked fuel pressure on buddy’s well-running 800 Dragon – same pressure as the other two readings
Fuel system Conclusion – I do not believe it is a fuel / pressure issue, but the gauge may have been off as I was not getting 58PSI on any of these sleds
Electrical / ECU system:
- Ohm’d the stator – everything in specs
- Replaced the stator with another used one, which also ohm’d to service manual specs fine
- Replaced the voltage regulator with a known good voltage regulator (out of a good running sled)
- Replace the TBAP (temp / barometric sensor) with a known good one
- Unhooked all wiring to throttle control block to make sure there was no issue with the throttle switch / kill switch
- Took my Carls 860 ECU (they flash it to their own set of maps) to a friend’s who has a well-running 08 800 Dragon, unplugged his ECU, plugged mine in to his sled, and it started right up and idled and blipped the throttle, everything seemed fine, so my ECU should be good
So... what now? I really doubt the 2 crankcase fuel injectors would have both gone bad at once. I can take it in to the dealer (non-running) and see if they can read the last sets of codes that are stored, possibly it threw some codes when it was running crappy before it failed to start completely.
TPS a possible issue? Will it do this if TPS fails completely? Is there an easy way to tell if it is bad without taking it in to the dealer again?
Have an 08 Dragon with an 860 Carls in it. It was due for a new top end so I pulled the top end, put new Carls (Wiseco) pistons and rings in it along with new wristpin bearings and all gaskets of course. Reassembled everything, started it up, idles fine but I was getting a 7-blink code which is a cylinder fuel injector fault. Those injectors are not used at idle. Loaded it up on the trailer and took it in to the local Polaris dealer who hooked it up to digital wrench to figure out which injector was the issue, it read the pto side cylinder injector was at fault. Only other notable thing was the TPS was off a little, but it has always run fine.
So bring it home, chase the wiring / remove some electrical tape and rubberized moulding, hook up ohmmeter, and find there is an intermittent splice – the injectors had been changed out and spliced and the splice was a crappy job. Fixed it, measured with ohmmeter again, wiggled wires all around, no more intermittent connection. 12 ohms constant. So I figure it is fixed and ready to go.
So I put it back together again, start it up and now it acts like it is running on one cylinder, idled but boggy and would not pick up speed and then died. Realizing the injector wiring I just fixed was for the cylinder injector which does not affect idle... strange. One side of y-pipe was warmer than the other.
Now it will not restart at all. Good compression, nothing abnormal there. Here is what I have tried, one step at a time (I am giving summaries but the sled was basically attempted to be started at every stage):
- Spark plugs out and grounded – good sparks
- Put fuel into cylinders through plug holes, replace plugs - it fires right up and then dies when the fuel runs out.
- Fuel pump pressure tested – seemed low, so...
- replaced fuel pump with a loaner used one from friend.
- replaced fuel filter with new SPI filter
- checked fuel pressure – same as with the old pump
- checked fuel pressure on buddy’s well-running 800 Dragon – same pressure as the other two readings
Fuel system Conclusion – I do not believe it is a fuel / pressure issue, but the gauge may have been off as I was not getting 58PSI on any of these sleds
Electrical / ECU system:
- Ohm’d the stator – everything in specs
- Replaced the stator with another used one, which also ohm’d to service manual specs fine
- Replaced the voltage regulator with a known good voltage regulator (out of a good running sled)
- Replace the TBAP (temp / barometric sensor) with a known good one
- Unhooked all wiring to throttle control block to make sure there was no issue with the throttle switch / kill switch
- Took my Carls 860 ECU (they flash it to their own set of maps) to a friend’s who has a well-running 08 800 Dragon, unplugged his ECU, plugged mine in to his sled, and it started right up and idled and blipped the throttle, everything seemed fine, so my ECU should be good
So... what now? I really doubt the 2 crankcase fuel injectors would have both gone bad at once. I can take it in to the dealer (non-running) and see if they can read the last sets of codes that are stored, possibly it threw some codes when it was running crappy before it failed to start completely.
TPS a possible issue? Will it do this if TPS fails completely? Is there an easy way to tell if it is bad without taking it in to the dealer again?