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Thread: Miss

  1. #1
    Mitsu booster
    Join Date
    Nov 2007
    Location
    Charleston, WV
    Posts
    6

    Miss

    87 Daytona Shelby ZTurbo 2, 5 SpeedFWD-P Stage 3 Calibration, 2.5" Exhaust w/o cat or muffler Upon start up it runs great for approximately 20 seconds, and the starts to miss.Misses under vacuum conditions; runs great in boost.If I set the timing at 8 vs 12 btdc, I pretty much lose the miss at vacuum, but lose ~ 3" of vacuum at idle and lose ~ 2psig and responsiveness under boost. Vacuum at idle with timing at 12 ~ 18-19". Vacuum at idle with timing at 8 ~ 15-16". After replacing the O2 sensor, the idle is surging with timing at 12, but idle does not surge with timing at 8.Things I have done or checked: Cam Timing - Found it off by one tooth. Reset it and gained ~ 3" of vacuum at idle (timing at 12).Compression - 2 cyl at 140, 1 at 138 and 1 at 138Leak down Test - Will not hold, leaks into crankcaseHEP - Mopar, have swapped with others, no changeDistributed - No slop in shaft, shutter - no wobble, has been epoxied, new cap - wires lock securely, new rotorNew Ignition Wires and Plugs - have used Champions and Autolites. They look great, slight rose tint on insulator. Mopar PCV and PCV 'ell'New Coolant Temp Sensor - Voltages and fan on/off okVacuum Lines - Replaced all lines with FWD-P Silicone lines distribution blockNew Coil - NAPAFuel Pressure and FPR - good, although the pressure leaks down to ~ 30 psig with key offO2 Sensor - Replaced Bosch with NTK, and verified voltages - ranging from 0.25 to 0.85 VChecked Grounds - Found one missing and replaced it, but it made no differenceInjectors - When I got the car it had 2 different injectors in it (3 of 1, 1 of another). I replaced them with a set of BWD/Niehoff 57224 injectorsSpark Test - at least 25 KV all cylindersNo CEL light, although I did have codes 22, 24 and 35. I assume due to messing with CTS and due to idle surge. Will reset with timing set at 8 to see if they return.I have been through everything nearly twice. Any advice would be appreciated.

    ---------- Post added at 08:11 AM ---------- Previous post was at 08:01 AM ----------

    Moderator - why does the post run together, ie no line breaks?

  2. #2
    turbo addict
    Join Date
    Feb 2010
    Location
    Piedmont, Ohio
    Posts
    4,109

    Re: Miss

    Quote Originally Posted by 66CudaFormulaS View Post
    87 Daytona Shelby ZTurbo 2, 5 SpeedFWD-P Stage 3 Calibration, 2.5" Exhaust w/o cat or muffler Upon start up it runs great for approximately 20 seconds, and the starts to miss.Misses under vacuum conditions; runs great in boost.If I set the timing at 8 vs 12 btdc, I pretty much lose the miss at vacuum, but lose ~ 3" of vacuum at idle and lose ~ 2psig and responsiveness under boost.
    Vacuum at idle with timing at 12 ~ 18-19".
    Vacuum at idle with timing at 8 ~ 15-16".

    After replacing the O2 sensor, the idle is surging with timing at 12, but idle does not surge with timing at 8.

    Things I have done or checked:
    Cam Timing - Found it off by one tooth. Reset it and gained ~ 3" of vacuum at idle (timing at 12).
    Compression - 2 cyl at 140, 1 at 138 and 1 at 138
    Leak down Test - Will not hold, leaks into crankcase
    HEP - Mopar, have swapped with others, no change
    Distributed - No slop in shaft, shutter - no wobble, has been epoxied, new cap - wires lock securely, new rotor
    New Ignition Wires and Plugs - have used Champions and Autolites. They look great, slight rose tint on insulator.
    Mopar PCV and PCV 'ell'
    New Coolant Temp Sensor - Voltages and fan on/off ok
    Vacuum Lines - Replaced all lines with FWD-P Silicone lines distribution blockNew Coil - NAPA
    Fuel Pressure and FPR - good, although the pressure leaks down to ~ 30 psig with key off
    O2 Sensor - Replaced Bosch with NTK, and verified voltages - ranging from 0.25 to 0.85 V
    Checked Grounds - Found one missing and replaced it, but it made no difference
    Injectors - When I got the car it had 2 different injectors in it (3 of 1, 1 of another). I replaced them with a set of BWD/Niehoff 57224 injectors
    Spark Test - at least 25 KV all cylinders
    No CEL light, although I did have codes 22, 24 and 35. I assume due to messing with CTS and due to idle surge. Will reset with timing set at 8 to see if they return.I have been through everything nearly twice. Any advice would be appreciated.

    ---------- Post added at 08:11 AM ---------- Previous post was at 08:01 AM ----------

    Moderator - why does the post run together, ie no line breaks?
    Sometimes carriage returns are goofy and dont work. fixed it.

    Looks like its all pretty much in order. I would think maybe your flywheel notch is off and 8 degrees is actually 12. I have noticed on computer controlled timing that you dont get the absolute best idle vacuum. 4.0 jeeps only pull about 11in of vacuum and if you crank the cam sensor to give 20 in of vaccum they set cam sensor codes.
    Ian Adams Function>Form 1990 shadow scrapped, too rusty:( 1991 Spirit R/T Scrapped, parts sold:( 1989 Turbo Caravan Daily beater with built-[I]ish [/I]​engine slowly evolving into weekend turbo beater.

  3. #3
    Mitsu booster
    Join Date
    Nov 2007
    Location
    Charleston, WV
    Posts
    6

    Re: Miss

    Thanks shackwrrr

  4. #4

    Re: Miss

    With stocker computer how does it run?

  5. #5
    Mitsu booster
    Join Date
    Nov 2007
    Location
    Charleston, WV
    Posts
    6

    Re: Miss

    It runs the same with the stock LM

  6. #6
    turbo addict
    Join Date
    Oct 2006
    Location
    Oswego, New York, United State
    Posts
    1,568

    Re: Miss

    Are you sure all the pins on the connectors are tight to the LM? It may be in your best interest to get some spray cleaner and wire brush the LM connectors and tighten every pin on the plugs themselves. Its really not hard when you get the hang of it.

    Also, did you try wiggling the LM when the car was running to see if anything changed? Give it a try.

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