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Thread: Sniper Erratic Timing

  1. #11

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    I'll give it a close inspection and see what I find. What's the consequence of it running with a standard rotor? Lose 15° of potential advance?

  2. #12

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    My gut says to try replacing the screws for the rotor to none magnetic ones, and to check the carbon block in the cap to make sure it moves, and is not cracked.

  3. #13
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    Quote Originally Posted by BITE_ME View Post
    My gut says to try replacing the screws for the rotor to none magnetic ones...
    I mentioned that HERE, but I don't think the user tried it.

    Quote Originally Posted by 91chevota View Post
    What's the consequence of it running with a standard rotor?
    Nothing at idle, but rotor phasing issues at high RPM.
    http://documents.msdperformance.com/8644_tb.pdf (MSD Rotor Phasing Document)
    http://www.youtube.com/watch?v=aWMlNwGW0tM (MSD Tech - Rotor Phasing Video)
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  4. #14

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    Yep, you're right Danny. Also, the brass part of the rotor looks like a hammer head shark. I'm basing this from images on the internet. I would trim the "T" so it looks like "|" instead.

  5. #15

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    OK so tried it with the original rotor. Exactly the same problems, made no difference at all. Inspected both rotors, no difference in key dimensions.

    Pulled distributor out again to check over everything and noticed a little bit of movement between the shaft and the rotor. Snugged everything down and eliminated movement it's now solid as, however, it still hasn't fixed the issue. It's slightly better, but not good enough to idle properly.

    With disabled Idle Spark, it sits on 15° at idle, but randomly jumps to 30° every now and then for no reason. RPM still bouncing around, and won't idle down to 800 target.

    I'm pretty much out of ideas guys. Not sure where I'd even source non magnetic screws for it here, that's about the only other thing left I can think of to try. This is what it looks like, hot idle with idle spark disabled.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  6. #16

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    After everything I tried to fix this problem, I finally got it working.

    Completely ditched my old tune and started from scratch. Reset the distributor as per instructions and started the Wizard again. Started and sat there idling like it should. Stable spark, good AFRs, stable idle, etc. Rotor phasing isn't perfect, but close enough to not cause any problems with my numbers, so I decided not to touch it now that I finally had it running right. Put it all back together and took it for a test drive. So far so good. Also of note, the old problem it had of stalling after coasting is now gone, go figure.

  7. #17
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    So it was in the tune. Maybe the Learn Table was corrupted with erroneous values, or some Engine/Ignition parameter was set wrong.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  8. #18

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    It certainly seems so. I checked through all the hardware the tune was the only thing left.
    Something was anxiously amiss from the start with that Learn Table. Starting again it seems to be running much more like it should.
    I'll put some kms (miles for you guys ha ha) on it this week but it feels good so far. Thanks a lot for the help Danny.
    Last edited by 91chevota; 04-09-2017 at 08:59 AM.

  9. #19

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    There's little to lose by at least, trying a new tune. The 32 GB SD card in the handheld has enough data storage to save thousands of different tunes. It's simple to switch between tunes. I can see having a nice gas tune, an E85 tune, and maybe something in middle since Sniper EFI doesn't support a Flex Fuel sensor.

  10. #20
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    Quote Originally Posted by 351C Sniper View Post
    The 32 GB SD card in the handheld has enough data storage to save thousands of different tunes. It's simple to switch between tunes.
    True, I do the same thing for a different reason (LINK).
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

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