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96' Procharged Cobra "Casper" Build

Discussion in 'SN95 Cobras' started by 01silverstang, Feb 24, 2021.

  1. 01silverstang

    01silverstang Well-Known Member Established Member

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    Yeah, that's what I'm hearing... not sure if I should just take it to an exhaust shop to have all the connections gone through, new gaskets and have everything tightened up. Not sure what could be causing this... without triggering a code?
     
  2. jman37

    jman37 Active Member Established Member

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    MA
    I'm no expert or anything but my car still has the EGR system and all air pump stuff still in tact, though I can't imagine that making a difference. Before my tune I had a CEL for 02s since it has no cats and that was it.
     
  3. 01silverstang

    01silverstang Well-Known Member Established Member

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    Ok so no arcing seen in the dark with the engine running... I did plug in my scan tool and here is the live data, can people smarter than me give me some guidance.

    DTC_CNT 3
    FUELSYS1 OL-DRIVE
    FUELSYS2 - -
    LOAD_PCT (%) 24.7
    ECT (Degrees) 89
    SHRTFT1 (%) 0.0
    LONGFT1 (%) 0.0
    SHRTFT2 (%) 0.0
    LONGFT2 (%) 0.0
    RPM 1026
    VSS (MPH) 0
    SPARKADV (Degrees) 16.5
    IAT (Degrees Fahrenheit) 57
    MAF (lbs/s) 0.02
    TP (%) 19.2
    AIR_STAT Off
    02SLOC B1S12 - - B2S12 - -
    02B1S1 (V) 0.000
    SHRTFT B1S1 (%) 0.0
    02B1S2 (V) 0.000
    SHRTFT B1S2 (%) 0.0

    My interpretation is that my MAF isn’t reading correctly and is a little low. It appears the 02 sensors are not plugged in and therefore I have no fuel trims. IAT looks good, Spark Advance looks good... vacuum on the boost gauge held steady at 22, so no apparent large vacuum leaks. I’m thinking I need to figure out where the connectors are for the 02’s and get them plugged back in and see how the live data changes, and then look into my MAF numbers more.
     
    Last edited: Apr 22, 2021
    mysteed likes this.
  4. DaveWertz

    DaveWertz Active Member Established Member

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    Hughesville Pa
    I have MAC LT, MAC X-Pipe and SLP LM-1s and mine sounds very similar to yours at startup. Maybe a bit louder. But at WOT its insanely loud, sounds good but loud.
     
  5. 03cobra#2

    03cobra#2 Hobbyist Of Many Hobbies Established Member

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    I see ect is only at 89. Get it up to full operating temp and log again.

    Sent from my Pixel 2 XL using Tapatalk
     
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  6. 01silverstang

    01silverstang Well-Known Member Established Member

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    Once I get it jacked up and make sure the 02’s are plugged in I will. I also got feedback that TPS is off, as it should be closer to zero at idle. Trying to determine if this is caused by the idle screw being off or if the TPS needs a relearn or is bad?
     
  7. 98 svt

    98 svt Premium Member Premium Member Established Member

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    Did you touch the idle screw?
     
  8. 01silverstang

    01silverstang Well-Known Member Established Member

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    No I didn’t, but I found enough other strange stuff on this car that it could have been messed with by previous owner... I’m still at a loss for when and why they removed the plug from the top of the throttle body. It may also explain my hanging idle when putting the clutch in during the maiden voyage.
     
  9. 01silverstang

    01silverstang Well-Known Member Established Member

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    Jacked up the car and tried to plug the 02 sensors in, but they didn't want to seat well. Was looking at Rock Auto and some were listed as downstream only, wondering if that's the problem, could these be the downstream and the connector is different? I'll order new NTK OEM 02 sensors but would rather not spend the $80 if I'm going to have the same issue...
     
  10. DSG2003Mach1

    DSG2003Mach1 Premium Member Premium Member Established Member Single Barrel Sirs

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    cant you look at the connectors and tell if they're right or not? I would think the up and down stream would have different connectors if nothing else
     
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  11. 01silverstang

    01silverstang Well-Known Member Established Member

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    I got so frustrated that I went back out and jacked it up again. Got the driver side connected, the passenger side sensor had bent pins which I couldn’t straighten out. Started it up and drive side registered on live data and the engine idle smoothed out immediately. I went ahead and ordered two NTK 02 Sensors from Rock Auto.

    Did find out the Air Fuel gauge is not connected to the exhaust, so I’ll have to have a shop weld some Bungs in and buy the sensors.
     
  12. robvas

    robvas Active Member Established Member

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    Use the rear o2 bungs?
     
  13. 01silverstang

    01silverstang Well-Known Member Established Member

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    Definitely an option but they are pretty far down, not sure if that’s a problem for wide and readings.
     
  14. BOTTLEFED5

    BOTTLEFED5 booost+spray= me Established Member

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    Man seems like someone really didn't know what the hell they were doing with this car lol. I think i might still have my old engine harness laying around, ill check.

    Sent from my SM-G965U using Tapatalk
     
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  15. robvas

    robvas Active Member Established Member

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    Working good for me

    BBK X pipe
     
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  16. 01silverstang

    01silverstang Well-Known Member Established Member

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    Yeah the original owners put a lot of money into this car, the more recent owners did some strange stuff.

    Thanks that’s good to know, mine is a BBK H-Pipe now that I’ve gotten under far enough to inspect.
     
  17. 01silverstang

    01silverstang Well-Known Member Established Member

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    So went to the junkyard this weekend and managed to find a front passenger side ABS/Wheel Speed Sensor, $10 and I should be back in business with no ABS light. The current sensor wasn't well secured and the wheel rubbed through the wire.

    My Amazon special LED fog light bulbs came, I was able to throw one in quickly to test and I think they look pretty good. Need to adjust the fog light and bumper to get better fitment, and need to do the re-pin under the center console so I can run the fogs with just the running lights.

    fog-light.jpg

    Hopefully the new NTK 02 Sensors will arrive this week, and I can find a way to adjust my idle screw without damaging it.
     
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  18. 01silverstang

    01silverstang Well-Known Member Established Member

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    Late to post but got a couple things done this weekend. My new OEM 02 sensors arrived, and I was able to get them both installed. The car still ran rough immediately after, but I'm assuming there is some amount of time for the PCM to start receiving the signal and then to make adjustments. I should have let it idle longer to verify, but got frustrated that it wasn't a more immediate change and moved on to other things I needed to do.

    I removed the drivers side PCV from the vacuum line as others recommended earlier. I still need to find a place to mount my catch can which is rather large, but I have everything I need for that once I figure it out. I also removed the intake tube from the throttle body and hit it with some carb cleaner to make sure the blades weren't sticking. It appeared to be entirely closed and while I did PB blast the idle stop screw, adjusting it didn't seem to make a visual difference, I would have assumed based on the 19.2 (%) reading from live data on my scanner that the blades would appear to be open at idle, but they didn't. After some adjustment the percentage dropped to 18.6 (%) which makes me wonder if the TPS is faulty, or needs adjustment. I know the earlier SN95 were adjusted by loosening the screws and moving it until it read proper voltage. If it's not adjustable then the sensor may just be bad?

    When re-tightening the intake elbow, it caused the lower connector to pop off after I went to start it... car sounded cammed and boost gauge was showing like 4-5 for vacuum. Got it reconnected well, and started it and it was very smooth. Being the scientist I am, I can not point to any specific cause because I didn't isolate each change like I should have lol.

    I wasn't able to get the wideband running correctly, as I assumed it used a LSU 4.9 sensor, and found out it's old enough it uses the LSU 4.2 sensor. I couldn't find any cheap alternatives that looked trustworthy so I guess I'm out $80 for a Bosch unit. If anyone has used a cheaper alternative with good results please let me know.

    I ended the day installing the passenger fog light bulb and re-pinning the harness while my son "drove" his Cobra. Now it allows the fog lights to run with the corners only.

    sideshot.jpg

    fog-light-mod.jpg
     
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  19. DSG2003Mach1

    DSG2003Mach1 Premium Member Premium Member Established Member Single Barrel Sirs

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    It doesnt start paying attention to the O2 sensors until it goes open loop (I forget what coolant temp that occurs) . Im not sure how much of open or closed loop idle is from learned data, disconnecting the battery and turning the lights on for a minute should clear most of that. If you do that I believe they say to let it idle with the AC off for at least 5-10 minutes then turn the AC on and let it idle another 5-10.
     
  20. 01silverstang

    01silverstang Well-Known Member Established Member

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    Once I get the TPS reading correct and verify if the sensor is bad, I'll go through the steps you outlined.
     

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