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Thread: 06 C6 Texas Speed Bfd Chopmonster cam swap Hard/No start issue

  1. #1
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    06 C6 Texas Speed Bfd Chopmonster cam swap Hard/No start issue

    After doing this BFD Chopmonster cam swap. Got on dyno, and noticed a no start/Hard start issue. Never really had this happen on a vehicle. It will only start if I flood clear with throttle pedal. But still starts poor. Never had a cammed vehicle do this ever. Usually once getting fueling in, they always start. But has anybody ran into a hard to start issue after a decent size cam swap, that only a flood clear will get the car to light off?
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  2. #2
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    Pop the rails and injectors out and see if ones leaking. I've had them brand new out of the box get stuck open. If injectors check out and you know the part number on them matches what they're supposed to be (seen that one too - a few times actually) then start looking at your cranking fuel, air and spark.
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

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  3. #3
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    Yeah, it's weird, it started fine before we did the Cam swap. We did a baseline on dyno before the mods, granted, I only started it maybe 3 times total before tearing it down for the cam.. I've never needed to touch cranking fuel on a vehicle before after cam swap or anything for that matter, but you never know.

  4. #4
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    Give it some timing. Like a lot more.

  5. #5
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    So, I cranked the Startup airflow to abnormal levels and decreased the Cranking Ve to 60%, which I have never needed to do, but that is what get's it to fire off reasonably well. So I'll see if it cold starts fine in the morning...

  6. #6
    Senior Tuner edcmat-l1's Avatar
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    That's a pretty stout cam. It's gonna take about what you've done already to make it fire off correctly.

    Need to dial in the VVE. It's untouched. That will help a bunch with everything including startup.

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  7. #7
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    This needs a lot more cranking airflow IMHO.

    it also looks like VVE was roughed in but not tuned. Tuning this will make a good difference.
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