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Thread: Sniper idling issues.

  1. #1

    Default Sniper idling issues.

    I've had my Holley Sniper for over three years, but the last time I went to drive it was cutting out. Checked and most of the plugs were fouled. Cleaned but no help. Acts like it's starving for air, pulled a vacuum line off and it started idling better. Noticed IAC way up there, but I had it tuned in before without issues. Tried to retune the throttle blades, but couldn't get the IAC below 15-20% without the engine running away. Maybe stuck injector? Restarted a few minutes ago to do a datalog and it sounded much better. I noticed IAC was up around 40%. As soon as I went to adjust the throttle blades, it started surging badly and I caught it on a datalog, IAC all over the place. Can someone help with this?
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  2. #2

    Default

    If it's been running fine for three years then started acting up, it would be a mechanical issue not a tuning issue. Maybe a tank of bad gas, a stuck injector, a bad coil, worn out plug wires, plugged filter, etc. Something has gone bad in the system, so you'll just need to work the list.

  3. #3

    Default

    Did you only clean the plugs? If so, first thing to try is replacing them with new plugs. May not fix it, but do that first then go from there.
    69 Camaro
    400 SBC, ProCharger D1SC
    1.302 60', 5.95@116.4 on pump gas

  4. #4

    Default

    OK, here’s something else I noticed yesterday. Sniper is reading fuel flow 35 lbs/hr and a 7% duty cycle when engine is off?

  5. #5
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,105

    Default

    That's normal for key-on/engine-off.
    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.

  6. #6

    Default

    Fuel pressure good, coil swap no change. I'll order a set of plugs.

  7. #7
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,105

    Default

    Yeas, if the spark plugs have been fuel saturated, they'll need to be replaced.
    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.

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