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  1. #1

    Default '83 Thunderbird Turbocoupe Cylinder 3 Dead

    This car has no title, and we are going to use it as a rally car in a local race. That being said, we have run it pretty hard and have lost cylinder 3. Car is a 1983 Thunderbird Turbocoupe with 5-speed. A friend and I pulled it out of a field and tried to get it running again. We ran into stuck injectors, the camshaft being mistimed and many engine harness wires that were chewed through. After all fixing these three issues, we got it to start and run decent enough to drive around a field. The car would run very poorly until it hit boost, then it would clear up and take off. We assumed that this running was the result of our poor timing without a timing light and the computer being in open loop because the O2 sensor wire is chewed through (I am not familiar with this EFI system, so I'm just applying knowledge that I've learned in classes from late model vehicles).

    Earlier this week, we had it out in another field and we lost cylinder 3. Cylinder 3 has now become a dead miss at idle, with removal of the plug wire of cylinder 3 not affecting the engine running (with every other plug wire doing so). Since then, we've properly set the timing to 9* with the spout connector disconnected, new plugs (hotter range to 'clear' oil fouling if that was an issue), plug wires, looked at the cylinders through a bore scope (they have clearly suffered detonation), compression test (all cylinder 150, cyl 3 was slow to reach 150, but did), leakage test (cylinder 3 15% leakage), looked at cam lobes and pulled the fuel rail and watched fuel spray from all 4 injectors. We also checked and the cam is still in time. We think we have everything we need to run, and can't figure out why it won't. An instructor used manifold vacuum and a picoscope to verify the valves were opening by looking at pressure changes in the intake and exhaust, and the valves are being actuated properly, as far as we can tell. Our only thought now is to switch fuel injectors between cylinders and see if the miss follows the cyl 3 injector.

    Any suggestions on what direction to head now?

  2. #2

  3. #3

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    Update from my friend- apparently at the rail, injector 3 had a lot of junk in it. He's going to keep cleaning and put it back together and see how it works.

  4. #4

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    I use a paper clip then blip the throttle to do the balance test.

    The 2.3's are famous for having cracked heads.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  5. #5

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    Another updated- it's back to all 4 cylinders! That's good news. My friend told me that it still runs poorly until it hits boost, then it clears up. We have the 1-wire O2 sensor disconnected and the 2-wire sensor that goes to the bottom of the intake manifold disconnected (we are not sure what this sensor is, manifold intake temp?). Any ideas why it would run like a dog until boost?

  6. #6
    FEP Super Member xctasy's Avatar
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    Spray pattern. If the injectors don't cut a perfect spray fan, and don't mak the peak cc/minute flow rate at the test pressure, your wasting time trying to tune it.

    Bosch quality is awesome, but the injectors are propably out of spec due to age or particulates in them.

  7. #7

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    Its running rich. Probably in limp mode so it throws fuel at it to keep it from blowing up when a critical sensor fails. Under boost it will "clean up" some since anything over 50% throttle is usually full open on the injectors anyways.

    You really need to take the 5 minutes it takes to hook up a test light and a paper clip. The computer will tell you why its running bad, specifically sensors.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  8. #8

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    Appreciate the help so far guys. We got the car down to Springfield today in preparation for the race on the 11th. We put in a new O2 sensor and that seems to have helped. The sensor that's now totally broken and gone in the intake was a knock sensor, and a replacement is 'special order' from O'Reilly's... so we will not be having that sensor.

    We knew that the radiator was pretty nasty from sitting, but it's worse than expected. Only a few fins are visibly spitting water through, and most are just too plugged up with scale.

    The car actually idles well and runs well, even into boost, with very little throttle input. However, when you give it too much throttle, it breaks up really badly. My friend and I are thinking that the injectors just can't handle 100% duty cycle.

    Haystack, we are planning on jumpering that diagnostic connector tomorrow and seeing what it comes up with.

    Thanks guys

  9. #9

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    Any tips on how to get the codes to flash? Ours won't do any flashing

  10. #10

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    https://youtu.be/z0ehA8cFTkc
    https://youtu.be/9QSiS6wf7oU

    This is me pulling codes and showing how the process works and how its hooked up for someone on another forum.

    If it still doesn't work, then you may have to do a efi no start test. Google sbftech no start and chase through stuff with a volt meter or a test light.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  11. #11

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    the Thunderbird made it to the redneck rally cross, but sadly did not survive the B-feature. I think the transmission gave up, the engine will rev in gear without the car moving at all. Good news is we got it running really well and it was definitely the fastest car in the B-feature before it died...

  12. #12
    FEP Senior Member 83GTJIM's Avatar
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    Photos or be banned!

    ...or Dad will do it.
    Attachment 116762
    Last edited by 83GTJIM; 11-11-2017 at 09:27 PM.
    MCA #110307
    "Saved" 25k mi 83 GT - http://vb.foureyedpride.com/showthre...ght=Wrecked+GT
    83 GT T Top
    83 GT Convt
    84 20th Anniversary T Top GT350 SOLD 11/17
    84 GT Convt SOLD 08/18

  13. #13

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    Stick swap is stupid easy on those. Basically just like a 4 banger mustang.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  14. #14
    FEP Super Member erratic50's Avatar
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    That car is far too nice to do that to it. Terrible fate.

  15. #15

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    The number of pi is sure funny! Must be a fellow engineer?

  16. #16

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    Quote Originally Posted by foot2floor View Post
    The number of pi is sure funny! Must be a fellow engineer?
    The driver and owner of the car actually is an engineering tech student! Glad someone else thought it was clever!

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