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Getting spark to only one cylinder

ATV PRO #11 said:
I remember from a couple years ago. I was going to buy some stuff off him, but wasn't on last year much.

Question: Did you add that pc5 this season?
I ask because my cousin on his Polaris 850XP has a controller added to his and it caused the same thing. Once cylinder had no spark.
Ignorant on the subject but trying to help, I asked/helped him get an update for his controller. Updated it, and machine is running fine now.
It may or not be related but i've read pages and pages on this site. Seems 99% of issues are ground related (older phazers) or in need of some sort of electronic update.
Click to expand...


Good point. I had a PC5 on my motorcycle that caused a major over fueling. Disconnect and try.
 

ATV PRO #11 said:
I remember from a couple years ago. I was going to buy some stuff off him, but wasn't on last year much.

Question: Did you add that pc5 this season?
I ask because my cousin on his Polaris 850XP has a controller added to his and it caused the same thing. Once cylinder had no spark.
Ignorant on the subject but trying to help, I asked/helped him get an update for his controller. Updated it, and machine is running fine now.
It may or not be related but i've read pages and pages on this site. Seems 99% of issues are ground related (older phazers) or in need of some sort of electronic update.
Click to expand...
No, it already had the PC5 with autotune, and the O2 sensor. The only thing I've added to it is miles and plastidip on the bodywork.
 
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Still unplug the PC5 and see if the problem goes away. When I had one on my motorcycle it over fueled so bad and so much white smoke was coming out the back that I though I had blow a head gasket. The PC5 had already been on the bike for around 5 months before the failure. Easy thing to check then check the wiring on the coils.
 
Attempted starting with PC5 disconnected, no difference.
Checked for shorts and breaks in coil wiring.
Tested resistance on crank position sensor and throttle position sensor.
Swapped coils/plugs (not new coils, but between cylinders), but we do have power to both coils.

Only thing left really, is bad ECM?
 
Anyone have a phazer ECU that they would let us plug in just to make sure that it is in fact the ECU?
 
henks said:
Attempted starting with PC5 disconnected, no difference.
Checked for shorts and breaks in coil wiring.
Tested resistance on crank position sensor and throttle position sensor.
Swapped coils/plugs (not new coils, but between cylinders), but we do have power to both coils.

Only thing left really, is bad ECM?
Click to expand...

Did you get one of the two wires on the coils to flash the test light while you are cranking the sled over. The on/off voltage is what causes the coil to fire. I believe the ECM is the driver for the coil. Check a wiring diagram to confirm. I do have a spare ECM but it's probably a ways from you.

Ohm test the control wire (flashing wire) on each coil to confirm that there isn't a bad connection. ECM failures are rare. Most problems are bad conections or broken wires.
 
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OK I looked at the wiring diagram for you. There is a Red/White wire that is common on both ignition coils that will have 12 volts when the key is in the on position. The other wires are grey/red that is the control wire (flashing) for coil #2 (left side) that goes directly to the ECM. Coil #1 has a orange wire that also runs to the ECM. Test the orange wire and red/white wires to see if they flash when you turn the sled over. If they flash you don't need an ECM. If they both or one don't flash disconnect the harness from the ecm and locate the orange and red/white wire in the ECM connector. Disconnect the wires at the the coil side and check for continuity from the coil wires to the ECM. Report back.
 
Did that last night. Continuity from the plug side all the way to the ECM on both orange and gray/red. We never got any flashing though when trying to start.
 
Check the ground wires on the ecm. Basicall the ECM gets a signal from the crank sensor and will fire the coils. Check to make sure the ECM is receiving the signal. Do you have a wiring diagram?
 
I have a copy of the service manual, yes. But we know the ECM is receiving some sort of signal, as one of the cylinders is getting spark, just not the other. We tested the resistance on the CPS and TPS, and both were in spec as well.
 
Your right. I forgot you were getting one coil to fire so it must be getting the signal from the crank sensor. Do a final check on the grounds to the ecm and if they are OK you need a new ecm.

TPS will have no effect on the coils firing. If your firing on one cylinder CPS is working.
 
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Ruggybuggy said:
OK I looked at the wiring diagram for you. There is a Red/White wire that is common on both ignition coils that will have 12 volts when the key is in the on position. The other wires are grey/red that is the control wire (flashing) for coil #2 (left side) that goes directly to the ECM. Coil #1 has a orange wire that also runs to the ECM. Test the orange wire and red/white wires to see if they flash when you turn the sled over. If they flash you don't need an ECM. If they both or one don't flash disconnect the harness from the ecm and locate the orange and red/white wire in the ECM connector. Disconnect the wires at the the coil side and check for continuity from the coil wires to the ECM. Report back.
Click to expand...

We had 12V on both coils on the red/white wire. One of the first things we checked (after swapping the coils and still not getting spark on #2) was for continuity on that wire between the ECU and coil plug., which we had. Its not a bad/broken wire. Coil #1 (orange wire) didnt show a flash on a test light, but did show voltage on a volt meter when cranking. Coil #2 (grey/red wire) did not show a flash or voltage on the meter when cranking. We tested the Crankshaft Position Sensor (CPS) and it was in-spec. We only tested the TPS because we ran out of ideas and the service manual actually said to check that as part of diagnosing a no-spark situation, it didnt make sense to us why that would effect spark, and no sense to us at all why it would effect no-spark on only one cylinder but for the sake of being through, we checked it.

Henks went home for the week, but the sled is still here. I will check to make sure the ECU is getting ground, but we're pretty confident the ECU is the culprit since every other possible thing has been checked.
 
DigitalFusion said:
We had 12V on both coils on the red/white wire. One of the first things we checked (after swapping the coils and still not getting spark on #2) was for continuity on that wire between the ECU and coil plug., which we had. Its not a bad/broken wire. Coil #1 (orange wire) didnt show a flash on a test light, but did show voltage on a volt meter when cranking. Coil #2 (grey/red wire) did not show a flash or voltage on the meter when cranking. We tested the Crankshaft Position Sensor (CPS) and it was in-spec. We only tested the TPS because we ran out of ideas and the service manual actually said to check that as part of diagnosing a no-spark situation, it didnt make sense to us why that would effect spark, and no sense to us at all why it would effect no-spark on only one cylinder but for the sake of being through, we checked it.

Henks went home for the week, but the sled is still here. I will check to make sure the ECU is getting ground, but we're pretty confident the ECU is the culprit since every other possible thing has been checked.
Click to expand...

Take your ECM from your sled and give it a go. If your comfortable with that. If he ends up needing one I'm just north of you and could send one down. I'm in Canada but in International Falls usually once a month and could mail it.
 
I really wish I could! I dont know how many times I said I wish I still had my phazer, even more so now since I would be able to swap it over for him to confirm it was the issue. Unfortunately, I sold the phazer and the apex to buy the Viper last year.

I'll let you and Henks work out the logistics on the ECM thing.
 
henks said:
Attempted starting with PC5 disconnected, no difference.
Checked for shorts and breaks in coil wiring.
Tested resistance on crank position sensor and throttle position sensor.
Swapped coils/plugs (not new coils, but between cylinders), but we do have power to both coils.

Only thing left really, is bad ECM?
Click to expand...

When you swapped coils did the previously working one work on the cylinder that wasnt firing? How did you determine it was firing? Did the previously not firing cylinder then fire?

Ruggybuggy you are doing a awesome job helping out here. I just have a few questions and always suspect coils first since ecu is a very rare failure.
 
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