Hi all, first time posting so here it goes. This thing runs fine sometimes then others it doesn't want to start, idle or run with throttle. It backfires through intake sometimes. Checked codes, none present with hptuner. I don't have access to polaris scanner. I've checked fuel pressure and crankshaft sensor not shown in this capture, those checked ok. My question, is there supposed to be this much AC ripple on channel D? It seemed like allot to me so I replaced voltage regulator with a scamazon regulator. I'll post it as well. It's same but different so am I on the right track or should I be chasing T-map or something else? When it runs it runs great but then all of a sudden it'll start acting up. Or sometimes when first attempting to start it'll act up, no rhyme or reason.

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Attached is after new regulator

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After we spoke on the phone the other day were you able to make any headway?

No,  with the warmer weather it has seemed to fix itself.  This weekend it's supposed to be cooler so I'll try to do some testing and report back

For fun, I don't know Jack about this unit. And I was never a great Guru on burn front on ignition, but did note this is all over the place.  Of course burn front  as I was taught in  a perfect world 1-2 MS. Again depending this changes. I noted the fronts are all over the place, indicating fuel issues, or of course all that is also predicated on compression and such. Don't know if this unit has a Baro or as I stated don't know Jack about a Polaris.

Would be fun to have some old school guys comment on their impression of what I noted.

Larry

Thanks to those of you who responded. I know I don't owe an explanation for why it's been so long but business is good so I've been too busy to report back. A few days after posting I was able to fix it with a new battery. Yes I know we all should be testing batteries, alternators and starters anytime an erratic electrical problem occurs, especially a vehicle. But on a 4wheeler that doesn't crank slow, who would? (This guy from now on) :) In the file you're correct Larry, when it acts up it would misfire, because the ECM was wigging out due to the bad battery. I'm not sure I have much faith in PICO diagnostics and I'll attempt to post files showing why. The old battery showed, good needs recharging. I understand it was not fully charged but at 94CCA and resistance and such why didn't it just say replace? I replaced the battery and retested and it ran like a champ. So this reiterates the importance of testing the battery first in any electrical diagnostics and incorporating it into part of a service or PM

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