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Thread: Holley Sniper cutting out, losing power.

  1. #1

    Default Holley Sniper cutting out, losing power.

    I have a a new Sniper install that I am having some serious issues with. The system is completely losing power and I am out of ideas. Here are the details on the vehicle:
    '69 Chevelle Malibu
    Chevy Crate motor ZZ502 no modifications
    Removed Holley 870 CFM carb that came with the motor.
    Installed Holley Sniper 550-511
    Removed HEI distributor that came with the motor.
    Installed Holley Dual Sync distributor 565-100 with plug & play harness 558-493
    Removed gas tank and mechanical fuel pump
    Installed Holley EFI Conversion Fuel Tank 19-106
    Installed MSD Blaster Coil 8207
    Initial setup including timing is all verified and correct.
    The car ran fine with the original equipment. I made the change to improve cold start and running performance as I drive this thing a lot.

    Here is the problem. The car starts and runs fine. After doing some driving it starts to cut out and sometimes dies completely. Sometimes it happens after a few minutes. A couple days ago it drove fine for 45 minutes with no issues. The next night it made it to a car show 1/2 hour away. After the car show it barely made it home. I have several logs that don't indicate what the issue is. I have sent these to Holley tech but the problem is the entire system is losing power so the log stops when it hiccups. Holley said there is some RFI interference which I will discuss in a minute. My initial thoughts were that there was a problem with my power supply to the pink wires. I bypassed my switched ignition source where these normally go by attaching directly to the battery but that didn't help.

    Here are my questions:
    Would RFI noise cause the system to completely lose power? I mean power down and reset? This is whats happening. You can even hear the fuel pump restart when this happens.

    Would a fuel supply issue cause the system to power down completely? I doubt it but did notice my fuel hose was on top of my valve cover so I'm wondering if vapor lock is an issue. I have since relocated that but not driven it since. I don't believe this would cause power to be interrupted to the system but I need to ask.

    Could there be something inside the Dual Sync distributor causing this issue? Again, power being lost to the Sniper. Could the coil cause this?

    I ran out of ideas and took the car to a local hot rod shop that has experience with the Holley Terminator and Dominator series of EFI systems. He had no experience with the Snipers but in general they are the same. He could not get it figured out and even worked with Holley tech support for two hours on the phone. Still no luck. He finally decided the issue had to be with the Sniper system itself. A complete new Sniper system was purchased and installed including harnesses. Still no luck. The coil was relocated and the wires spread out in an attempt to reduce the RFI noise. Still bad. I am very close to just putting the carb back on. I'm disappointed because I really would like to have this but my driving season is 1/2 over and I'm getting anxious. I don't believe this is a Holley quality issue. It has to be something with my car but I'm not sure where to look. Any help is appreciated.
    Last edited by thunderbyte; 07-27-2018 at 08:10 AM.

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,931

    Default

    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 must 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.
    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.
    Originally Posted by Danny Cabral
    It's helpful to record a short datalog of an occurrence, Overlay it onto your Config File, and manually tune the lean or rich problem area.
    Look at where the live cursor moves to during this occurrence, and manually tune (enrich or lean) that area of the Base Fuel Table.
    When the engine is tuned & running well, you should decrease the Closed Loop & Learned Compensation Limits % to lock in a good tune.
    https://www.youtube.com/watch?v=rHjLwJQ45Kw (Holley Sniper EFI Datalogging Tech Video)
    http://forums.holley.com/showthread....7370#post47370 (Closed Loop & Learn Table - Especially posts #2, #6 & #11.)
    Originally Posted by Danny Cabral
    Quick Datalogger Information:
    Always provide data, not just symptoms. Is the AFR & ignition timing optimized? Overlay the datalog onto your Config File.
    Ensure the Target A/F Ratio table is properly programmed for your engine. Ensure the ECU is "Learning" (Learn Table LINK).
    Scroll through the datalog to the problem area. Then look exactly where this happens on the Base Fuel & Timing Tables. Scrutinize:
    RPM, MAP, MAT, TPS, CTS, IAC, Target AFR, AFR Left, CL Comp, Ignition Timing, Duty Cycle, Fuel Flow, Fuel Pressure & Battery.

    Using the Holley EFI software (LINK), look at where the live cursor moves to during this occurrence, and
    manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing).

    I find the most helpful datalog function, is overlaying the datalog on your Config File.
    I'm in the habit of using the datalog Overlay feature every time I review a datalog.
    Click on "Datalog" (on the top Toolbar), "Activate Overlay", then "Open Data Log".
    You can literally "playback" a recorded event, and watch it as it happened on any screen.
    Minimize (shrink) the datalog window, and move it to the bottom of any Config File screen.
    Then click & scroll anywhere on the datalog, and watch it playback on your Config File (EFI software).
    http://documents.holley.com/techlibr...9r10543rev.pdf (Holley EFI Datalogger Instructions)
    https://forums.holley.com/showthread...s-amp-Datalogs (Datalog Information - Read "NOTES")
    https://www.youtube.com/watch?v=iqHO...C6FEA0BB99AF17 (How To Record & Email A Datalog)
    https://forums.holley.com/showthread...7531#post77531 (Closed Loop Datalog Tuning - Posts #2, #4 & #6)
    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/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 & 245/45R17 tires.

  3. #3

    Default

    The datalogs don't indicate what the issue is because when it happens, it's completely powering down the system immediately stopping the datalogging. Even Holley tech support did not find anything on the datalogs provided. I was really hoping for plug & play. Again, I'm not upset with Holley. This is likely something specific to my car. I'm going to again confirm timing, settings and go over all connections. I will also revisit all my ground connections. If this doesn't work I'm going back to a carb setup.

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,931

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    IF you think it's a wiring/connectivity problem, ensure the Switched +12V pink wire remains powered in the "Run" and "Crank" key positions. Some people have experienced momentary loses that cause the ECU to reset itself. As a test, you can temporarily connect the pink wire directly onto the battery terminals.
    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/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 & 245/45R17 tires.

  5. #5

    Default

    Attaching the pink wire directly did not help. I've since replaced all of my grounds and still no luck. Would a faulty coil cause this to happen? I can't imagine that it would, but I'm running out of ideas. It primarily happens once the car is warmed up. I'm using a MSD Blaster coil.

  6. #6

    Default

    Shouldn't be too hard to figure out if the unit is losing power. It only gets power a couple of ways, so just look at those connections. Hook up a voltmeter to the ECU and drive it around. If it loses power, you'll be able to watch it on the voltmeter. I assume when you say it loses power, that only the Sniper loses power right? The battery still has 12 volts and the lights work and stuff like that?

    Maybe you aren't describing the problem correctly, since I doubt it actually loses power. Perhaps what you mean is that the Sniper has power, but it is resetting itself during operation? The pink wire would be the one to suspect in that case, so attach a voltmeter to it and watch and see. If the Sniper resets itself while the pink wire has 12 volts on, then you might have a loose connection inside the Sniper.

  7. #7

    Default

    I'm having the exact problem, resetting most morning starts. Once system warms up, it goes away and runs great. I've rewired pink, coil & battery connections. I can’t datalog because it resets. I believe it’s computer, cold solder or something like that. It's been two weeks on problem. System is four weeks old, ran good for first 10 days. I hope you have some luck or an answer to help fix this issue.

  8. #8

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    If it resets itself when cold, then just shoot a video and send that to Holley tech.

  9. #9
    Join Date
    May 2014
    Location
    Bostwick, GA
    Posts
    176

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    Good idea to volt meter the pink wire. I suspect this system is similar to the FiTech, and it could be a voltage drop to <10VDC.
    We have had 2 FiTechs fail to start, or die after starting. Both were due to low voltage. One was a bad cell in the battery, the other the customer had done some faulty wiring.
    Injector Inspector
    USAF 1960-1964
    Drag racing since 1955

  10. #10

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    I relayed it to the battery for a clean source. Voltage at pink is steady 14.2 even when resettin. And scoping for noise on circuit, it’s very clean no sign of extra noise when it resets. After 10 minutes idling, when it warms up good, takes longer driving as throttle body must take longer to heat with airflow.

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