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Thread: Sniper just stalls.

  1. #1

    Default Sniper just stalls.

    Been having problem with stalling at idle and light acceleration. Feels like ignition just turns off. I did notice in garage when it would stall, it always happens right before the signature pulse (HyperSpark distributor). Monitor display for throttle position shows minus percent and no data for other inputs, would start right back up. I've tested grounds and voltage supply and they test good. Do you think I might have a faulty Sniper throttle body? Data record of the stall looks like it's not recording correctly and seems to me like it loses it sync. Sniper 4150.
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  2. #2

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    Probably bad EMI. Lots of threads on that subject. You have to be careful in how you route the wires.

  3. #3

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    Thanks for the reply. I'll be doing some rerouting.

  4. #4

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    Anytime you have a Sniper that starts and runs, but then shuts off it's probably EMI. Most likely caused by having ignition wires close to Sniper wires. About half of the complaints on this board are from people who have EMI or RFI issues. The Sniper wires must be located as far as way as possible from any ignition wires. Once you solve that issue then start using the datalogger to debug any other issues.

  5. #5

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    Agree that it's most certainly EMI. Be sure you have a very high quality ground from the battery directly to the engine as well.
    69 Camaro
    400 SBC, ProCharger D1SC

  6. #6

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    I haven't found any EMI or RFI scope captures yet. I see some noise, but I don't see any problem. I moved harness around and still have stalling issue. I even replaced the alternator. It seems to stall right before sync on distributor, #2 ignition fire. Here's my spark plug wires. New.
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  7. #7

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    Please post a datalog of the event. That will be the only way we can really tell.
    69 Camaro
    400 SBC, ProCharger D1SC

  8. #8

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    Don't know how to download a datalog.
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  9. #9

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    Negative time means you have RFI noise resetting the ECU. You must have some ignition wires laying on some Sniper wires. Either that or you have solid core ignition wires and non-resistor spark plugs. You have to get rid of the electrical noise or else it'll never run.

  10. #10

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    I'm using NGK #8 racing spark plugs.. And I believe they're non-resistor plugs. That would be awesome if that's the problem. Thanks Andy. I'll let you all know soon.

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