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Thread: Holley Sniper issues?

  1. #1

    Default Holley Sniper issues?

    I took my car out for a spin around the block a few months back. Temperature was pretty chilly. Let the car warm up, and down the street I went. On the way back, I gave it some gas. It backfired, idled like crap (almost like it wasn't running on all 8), then shut off as I coasted back to my house. Since then, I'd try starting, and it would just die immediately. Try cranking with my foot on the gas pedal, same thing. Starts, then immediately dies. Gas tank is half full. Battery fully charged. What should I be looking for here? Hoping it's something simple.
    Car is: '77 Cougar. 460 big block, Sniper EFI, Aeromotive Phantom Fuel pump (in-tank).

  2. #2

  3. #3

    Default

    Thanks. I'll report back.

    Update: Checked the voltage off the Pink wire with the key in on position, and cranking. It's getting 12+ volts. I noticed my dash tach wasn't working, and the Sniper Handheld was not getting a reading (STALL!)
    Tore my dash, and loomed harnesses open. Checked wires for bad connections or breaks. Came up with nothing. Checked for resistance. Everything checked out OK. Checked the "Tach Output" voltage off my MSD 6AL box, it's getting 2.3 volts (should read between 1.5 to 5 volts).

    The car will now run (more like a slow chug) for a few seconds. Then it stalls out. I know the Sniper will not run without a RPM signal. However, this car ran great prior to the incident I mentioned. The factory dash mounted tach worked, and so did the tach in the handheld. My ignition system consists of an MSD 6AL (6420), MSD High Vibration Blaster Coil (8222), and a Crane Pro Curve Distributor (1000-1604). Nothing has changed with the car. No new parts. I'm just at a loss with this.

  4. #4
    Join Date
    Oct 2017
    Location
    Los Angeles
    Posts
    399

    Default

    Have you taking any datalogs of the event, and if not, can you take a datalog and post here for us to see? The datalogs can help pinpoint problems and is a great feature.

  5. #5

    Default

    Fuel pump?

  6. #6

    Default

    Quote Originally Posted by RPnova View Post
    Have you taking any datalogs of the event, and if not, can you take a datalog and post here for us to see? The datalogs can help pinpoint problems and is a great feature.
    I just took one, but not sure how to load the file here.

    Quote Originally Posted by Gen2Van View Post
    Fuel pump?
    The pump is/was brand new last Spring. I'd like to hope it's not the pump, but I guess anything is possible.

  7. #7
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,464

    Default

    Originally Posted by Danny Cabral
    Is the Sniper EFI Learning? Is the ignition timing synchronized? Is the fuel pressure 58-60 psi (LINK)? IAC Position
    of about 5% at hot idle? Check for ignition misfires/RPM signal problems, exhaust leak upstream of WBO2 sensor,
    or if the WBO2 sensor (or other sensor) has failed and corrupted the Learn Table. Look at the Data Monitor/Gauges.
    Also, the Holley Sniper EFI will intermittently inhibit Closed Loop at idle, if the AE vs TPS/MAP RoC Blanking values are set too low.
    http://documents.holley.com/techlibrary_199r11259.pdf (Holley Sniper EFI Help Manual)
    http://documents.holley.com/199r11369.pdf (Holley Sniper EFI Troubleshooting Guide)
    https://forums.holley.com/showthread...8356#post88356 (Holley Sniper EFI Fuel Pressure Tester/Gauge)
    Originally Posted by Danny Cabral
    For further assistance, post your Config File and a short datalog of this occurrence for us to analyze.
    Also, review the datalog and inform us of exactly where in the datalog (time/seconds) the problem occurs.
    Datalog & Global Files can be linked to a document hosting website. I use Dropbox.com.
    Files can also be "zipped" (compressed zipped folder) & attached directly to a forum post ("Go Advanced" & "Attachments").
    Your Config File is in the "Documents", "Holley" folder, "Sniper" folder, "Config Files" folder (.hefi file).
    Your Datalogs are in the "Documents", "Holley" folder, "Sniper" folder, "Data Log" folder (.dl file).
    Someone will analyze/troubleshoot the problem & offer advice.
    https://www.youtube.com/watch?v=iqHOtDNiTNA (How To Record & Email A Datalog)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & MT 245/45R17 tires.

  8. #8

  9. #9
    Join Date
    Oct 2017
    Location
    Los Angeles
    Posts
    399

    Default

    It seems like your IAC is really high. I doubt this is the problem, but I'd put a piece of tape over the IAC hole and try to start the car while the IAC is covered with tape and see what happens. If it does not start on its own, open the butterflies to let more air in while keeping the IAC taped off, and continue to open the butterflies until the car idles on its own. Other than that, I might bypass your CD box and run the yellow wire direct to your coil negative and change the Sniper settings to Coil- negative in the handheld and see if the CD box is your problem. Or try a known good working coil if you have one. Also, always post your GCF file when you post datalogs.

  10. #10
    Join Date
    Nov 2014
    Location
    Ont. Canada
    Posts
    1,494

    Default

    Quote Originally Posted by RPnova View Post
    Other than that, I might bypass your CD box and run the yellow wire direct to your coil negative and change the Sniper settings to Coil- negative in the handheld and see if the CD box is your problem.
    I'm not sure if it's in the Sniper instruction manual but putting your tach sense wire to the negative coil when using a CD box is not recommended with other systems.

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