Alpha 1 running on 1 cylinder

[Hunterm31]

For the last year I’ve been battling my sled running horribly and can’t pin point what is causing the issue. Currently, my 19 Alpha one with a speed werx stage 2 kit is running on one cylinder but the dead cylinder keeps switching from the PTO side to the throttle side. I’ve replaced the fuel injectors, the stator is reading out as normal, coil packs are providing the correct voltage, air intake is fine, tps is operating as normal and just about everything else is running within spec. Has anyone else ever ran into this?

 

[spoon]

Possible ECU issue with injector drivers. Ecu pins all in place properly?

 

[Hunterm31]

Possible ECU issue with injector drivers. Ecu pins all in place properly?

ECU is possibly in the cards, going to see if the stator is burnt out on a coil, or if the ignition sensors are fried.

 

[spoon]

Ignition sensors fire coils at same time. Would cause issue on both cylinders at same time.

 

[Octanee]

Reeds? Compression test?

 

[Hunterm31]

Reeds? Compression test?

Reeds are fine, cylinders are holding 120 psi. Not sure what the speedwerx high compression head is supposed to hold at but that seems fine.

 

[Hunterm31]

Ignition sensors fire coils at same time. Would cause issue on both cylinders at same time.

Thanks for the info, so the 2 ignition sensors don’t power different sides separately?

 

[spoon]

I sensor is for normal running, the other is for reverse.

 

[Hunterm31]

I sensor is for normal running, the other is for reverse.

I installed the new stator and I’m still cold on the PTO side cylinder. I’ve ran through just about the whole harness without finding any issue, pulled out the voltage regulator and there’s no physical damage and I don’t have/know a way to test if that has gone bad. My sled is also Rev limiting consistently at 6200 RPM. Any more input??

 

[spoon]

Is plug wet on that side? Is your compression and reeds good? Have you pulled pipe and looked into cylinders for damage? Rev limit could be due to exhaust valves not opening. Any codes coming up on dash? May also need to check signal to injectors if no fuel getting into cylinder. Possible injector issue? Lots of possibilities but need more diagnosis. Have you swapped plug wires to cylinders? They fire at same time, could be bad coil.

 

[Albatroz]

Did you run a compression test?

 

[Hunterm31]

Is plug wet on that side? Is your compression and reeds good? Have you pulled pipe and looked into cylinders for damage? Rev limit could be due to exhaust valves not opening. Any codes coming up on dash? May also need to check signal to injectors if no fuel getting into cylinder. Possible injector issue? Lots of possibilities but need more diagnosis. Have you swapped plug wires to cylinders? They fire at same time, could be bad coil.

Plugs are wet on both sides, compression tested and it’s holding 120 psi after pulling a few times, no pitting on the heads, but the exhaust valves were coated in carbon like it wasn’t burning off. No codes coming up, had a bad injector on the throttle side, I had the dealer replace that and then the PTO side went cold. Got it back from them and they were the ones who said they couldn’t figure it out and returned it to me running just as poorly as when I took it in.

 

[kanedog]

The dealer gave it back to you cuz they couldn’t fix it. Hmmmmm. Is there more to the story perhaps? Maybe you went in and screamed and yelled at people? Haha

 

[Hunterm31]

The dealer gave it back to you cuz they couldn’t fix it. Hmmmmm. Is there more to the story perhaps? Maybe you went in and screamed and yelled at people? Haha

No, they said they’re getting into this guessing game just the same and didn’t want to just throw parts at it and see. That’s why I’m running this issue across a forum to see if anyone’s had the same sort of issues.

 

[kanedog]

Approved.

 

[spoon]

Which dealer? Looks like Alpine Motorsports is your local dealer. They can't contact Cat tech for help? Should have enough parts on shelf to swap a few things to try. Could be ECU, maybe the other injector needs replacing as well. Harness chafing somewhere? Takes about an hour or 2 to remove harness to inspect it. Little longer if you have electric start.

 

[Hunterm31]

Which dealer? Looks like Alpine Motorsports is your local dealer. They can't contact Cat tech for help? Should have enough parts on shelf to swap a few things to try. Could be ECU, maybe the other injector needs replacing as well. Harness chafing somewhere? Takes about an hour or 2 to remove harness to inspect it. Little longer if you have electric start.

Yea I had it at AMS and they tested both injectors, found that the throttle side had clogged, replaced it, hooked it up to there scanner and couldn’t find any irregularities. They ran through the harness and were able to find any spot to have any abrasions or shorting out. They recommended trying to hook up another ECU but don’t have one for a 19, and the one they plugged in off of a 23 wouldn’t start the sled. They were the ones who recommended replacing the stator but had mentioned that was just going to be exploratory so I did it myself and it didn’t change anything. Since an ECU failed seems to be unheard of, I’m a bit hesitant to throw the $1000 down non returnable without knowing that that’s the issue.

 

[spoon]

Lots of guys parting sleds out. I have an 18 ECU from a Mountain Cat I did a Suzuki 1000 swap on. Engine was grenaded due to snow ingestion so ECU should be ok. Not sure if 18 will work with 19 due to harness changes.