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Thread: Sniper EFI Problems

  1. #1

    Default Sniper EFI Problems

    Hey all. New to the forum and new to Sniper EFI. Finished installing the Sniper on my 1969 Fairlane a few weeks back. The first 250-300 miles were amazing as the Sniper EFI worked flawlessly. Then Friday night as I was driving home, the car started acting up. As I would slow down for a stop sign or stop light, the car would run really rough and the idle did not want to come down. Stopped at a gas station to fill up with 93 octane, and when I put it in park, the idle was 1,500. Tried to rev is a few times to get the idle down, but it didn't work. Shut the car off, filled the tank and started it back up again with out a problem. Pulled out of the gas station and the car was super sluggish. Car was running rough and just not acting the same. Car sat for two day until now and when I went to start it today, it won't start. Just turns over and acts like it wants to start.

    The Sniper is installed very simply as I've only got it hooked up to an MSD 6AL and Ford electronic distributor. The one thing I did change on Friday before the problems we installing a PCV valve in one of the valve covers. The tube runs to a fitting on the carb spacer and not the Sniper itself. I put about 40 miles on it like this before I started having issues. Any ideas on what I should check?

  2. #2
    Join Date
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    Quote Originally Posted by alankulwicki7 View Post
    As I would slow down for a stop sign or stop light, the car would run really rough and the idle did not want to come down. Stopped at a gas station to fill up with 93 octane, and when I put it in park, the idle was 1,500. Tried to rev is a few times to get the idle down, but it didn't work.
    This seems like an electrical interference issue to me. Ensure the spark plug wires (or any other high voltage wiring) aren't too close to the IAC motor/wiring.
    https://forums.holley.com/showthread...PWM-IAC-Wiring (Read "Initial Baseline Idle Speed Screw Setting" & "Sniper EFI Idle Setting/Throttle Blade Setting")
    http://www.youtube.com/watch?v=s3R8whD3ZWg (Wideband O2 Sensor Test) Key-on/engine-off. Also, the sensor heater will time out, so you'll need to work fast.
    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

  3. #3

    Default

    Thanks for the info. You think it may be an electrical issue, even though the car ran like a top for 250 miles? Or could it be the WBO2 sensor? I don't really have a way to test it other than your standard home garage tools.

  4. #4
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    Quote Originally Posted by alankulwicki7 View Post
    You think it may be an electrical issue, even though the car ran like a top for 250 miles? Or could it be the WBO2 sensor?
    I'm leaning more toward an electrical interference (IAC) issue, not a WBO2 sensor issue.

    I don't really have a way to test it other than your standard home garage tools.
    No one implied that any special tools are necessary.
    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

  5. #5

    Default

    I will check the wiring when I get a chance. In the video you linked, isn't the person using a gauge or tester of some sort on the WBO2?

  6. #6
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    Quote Originally Posted by alankulwicki7 View Post
    In the video you linked, isn't the person using a gauge or tester of some sort on the WBO2?
    The 3.5" TSLCD is your AFR gauge. As I stated, I'm leaning more toward an electrical interference (IAC) issue, not a WBO2 sensor issue.
    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

  7. #7

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    Sorry, but I don't know all what the TSLCD is capable of. But wouldn't that have affected driveability from the get-go? The first 250 miles were flawless. Also, I'm not by my car now, so is the IAC on the back of the EFI? I think all of the EFI wiring on the firewall and right inner fender (away from the distributor & plug wires).

  8. #8
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    Quote Originally Posted by alankulwicki7 View Post
    But wouldn't that have affected driveability from the get-go? The first 250 miles were flawless.
    Are you referring to the WBO2 sensor or the IAC valve issue?

    Also, I'm not by my car now, so is the IAC on the back of the EFI?
    Yes, the IAC air inlet port is adjacent to the IAC motor.
    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

  9. #9

    Default

    Sorry, this was referring to the electrical issues, and not the WBO2 sensor.

  10. #10
    Join Date
    Dec 2009
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    Well, something changed since your first (flawless) 250 miles. It's hard for me to diagnose it from the internet.
    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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