98 Cobra issues - clutch noise and intermittent bog down

Discussion in '96-04 - 4V Specific' started by SnakeMedic, Jul 17, 2015.

  1. SnakeMedic

    SnakeMedic Member

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    Ok, first the bogging down issue. Intermittently and totally at random times when it happens (sometimes right away, sometimes after a few miles) I get an issue where it seems to bog down when letting off the gas, particularly at lower speeds. Like cruising through a parking lot in 1st and letting off as I approach a stop, it almost seems like I slam on the brakes. Other times, it is completely fine.

    Now, I had some issues with my speedcal previously. I was trying to adjust the ratios and it stopped working so I yanked it. Replaced the speed sensor on the trans just because why not. It was after doing all of that this first started. Is it possible that because the speedo is way off (actual speed 10mph and car reads over 100mph) it causes it do this sporadically? Or is it a coincidence it started at the same time as the speedcal removal? Oh yes, I am replacing the speedcal soon. Also, I did remove the odo worm gear since I was racking up way too many miles that I was not driving. I can't imagine that causes anything like this....

    Second issue is the clutch noise. I get a whine when the clutch is in, and it goes away when I let off. At first I thought TOB, but usually it is the opposite of when my problem occurs. Anyone else had this issue? A few months ago there was a loud pop when I pushed in the clutch, but no changes in feel or driving after that. This problem is slowly getting worse, and has only started recently and not right after that pop sound was heard. The pop seemed to come from the pedal area, and not the transmission itself.

    Appreciate any help!!
     
  2. SnakeMedic

    SnakeMedic Member

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    Well it is definitely the throw out bearing. I confused myself previously.

    Kind of shocked that no one else has had speed cal issues or the whole bog down thing. I am the lucky one it seems. Can't wait for my $100 card from the UCA replacement thing.
     
  3. lutter94

    lutter94 Well-Known Member

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    Which speedcal do you have? I have a ford racing unit that works flawlessly.
     
  4. SnakeMedic

    SnakeMedic Member

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    It had an Abbott ERA in it, but I took it out because it stopped working and would make the car shut off randomly when slowing. I can't say for sure, but this whole bogging down BS seems to have started around the same time as that. So, might be related.

    I will be putting in one from a more reputable company when I get that free $100. Abbott seems to not be in business anymore.

    I still have no clue why a speed cal was in there on the first place. When I bought the car it sat on stock wheels and as far as I can tell based on behavior of the revs and whatnot it has stock gearing, but when the ERA was working it was still about 10mph off. Weird.
     
  5. lutter94

    lutter94 Well-Known Member

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    i believe pins 15/16 are vss + / - (gray/black, pink/orange), all respectively. It is on my car, assuming the same on yours. Could check continuity from the trans harness connector to the sensor itself.
     
  6. SnakeMedic

    SnakeMedic Member

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    Yeah, did all that. I went to try to figure out the ratios and at some point it came disconnected. I think it shorted itself out when a wire touched metal. Thanks for the thought though.

    What I found interesting was that the OEM speed sensor was not there, according to part numbers. OEM is supposed to be the one with the gear on/has the sensor plug plus another round part on the outside vs the one that was on there which was just a spot for the sensor. I assume when you put a speed cal in you change the VSS/speed sensor?
     
  7. lutter94

    lutter94 Well-Known Member

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    no, I had the factory AODE, put 3.73's in (had 3.27). bought the speed cal, wired it in on the firewall. It reads the factory sensor, and adjusts the signal. and sends it to the car. Swapped to a 99 V6 T5, it was electronic sensor only (no gear to change), the speedo was way over 100 at like 30-40mph. did some math, adjusted it, got it back down to the correct speed.

    This is your sensor
    http://www.latemodelrestoration.com/item/LRS-9731A/94-98-Mustang-Speed-Sensor
    [​IMG]
     
  8. SnakeMedic

    SnakeMedic Member

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    That is not the sensor I pulled out of the car..... Mine looked like the one on the right in this pic:

    [​IMG]
     
  9. lutter94

    lutter94 Well-Known Member

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  10. SnakeMedic

    SnakeMedic Member

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    That is what I found out. Which would lead you to believe I have a different trans. But, when I looked into it, it was in fact the factory trans. So, what gives?

    So weird. This has not been the first time this car has baffled me. Worst thing about not knowing a lot of its history. Have to sort it out, and sometimes you just can't. Can't figure out the speedometer and why it is off.

    Correct me if I am wrong, but a speedcal fixes a gear ratio or different wheels right? If mine is stock in wheel diameter and stock gears with no speedcal shouldn't the speedo be correct?? So that should mean that the wires that go to the speedcal from the sensor is causing the speedo to be off, right? I left the wires from the ERA in to ease installation of the new speedcal. Maybe I should just remove the wires and see what happens?
     
  11. lutter94

    lutter94 Well-Known Member

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    To install a speed cal you have to cut a vss wire feed it into the box and it has an output wire that taps in to where you cut. If you remove it you have to reconnect the vss wire

    What makes you think thats the right trans? And not out of a car thats a year newer. I'm guessing the new style sensor has a different output cal, similar to how my 99 t5 was initially reading 4-5x higher than GPS speed.
     
  12. SnakeMedic

    SnakeMedic Member

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    The tag on the trans shows the dates (IIRC) or something that led me to believe it was correct. Or perhaps it was the model number that denotes it is the right T45, which means it could be the 99 model. I am trying to remember what led me to believe it is the 98 T45... but I can't recall the exact reason. Dammit.

    There is the fact that before I took out the ERA it was causing the car to shit off randomly as I slow down. Since I removed the ERA it does not do that anymore, now only the speedo is way off. I wonder if I reconnected the wire you speak of (not sure of the color off the top of my head, but I cold figure it out easily) that would fix the issue. Interesting.

    The likely throw out or clutch release bearing noise is getting way worse. Now it sounds like something is kind of rubbing, almost like a more metallic chirp as it spins or whatever when the clutch is pressed. I do not like any abnormal noises. At least this is something that can be driven for a bit before fixing, though I hate doing it.
     
  13. lutter94

    lutter94 Well-Known Member

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    Just saw online that 99+ uses an OSS speed signal, as opposed to a VSS. I believe thats the scenario I encountered with my 99 T5 transmission. A speedcal will correct it to the VSS signal that your car expects to see. Post up what colors the old speed cal box was wired to, maybe a pic or two. I'll do the best I can to help, hope it gets straightened around. The TOB sounds like its seen better days.
     
  14. SnakeMedic

    SnakeMedic Member

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    Will do. I took some pictures of some other odd things I found around the pedals. I also considered that my quadrant went bad. Maybe was that "pop" I heard some time ago. It seems fine, but I found some odd things. Will post those in a different thread. A harness not plugged in and something that seemed disconnected above the brake pedal....

    I will get pics of those wires either today or tomorrow. Teaching a class all day then work at 1900. May not have time to do it today.