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Rough 1st and 2nd gear FD

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Old Oct 1, 2019 | 10:07 AM
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Rough 1st and 2nd gear FD

My 1994 RX-7 is a little rough on first and second gear but smooths our a bit in the later gears. Taking my foot off the pedal causes the car to jerk as well as putting my foot back on the pedal but any pressure given to the pedal once pressure is applied doesn’t jerk the car. Only when the pedal has absolutely no pressure it starts to jerk and as soon as it gets pressure it does the same. Pretty annoying for the low gears when you’re trying to drive slow and keep putting your foot on and off the pedal. A friend told me it was bushings that need replacement. Any thoughts?
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Old Oct 1, 2019 | 10:08 AM
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Side note, no weird noises or rough idling or rough shifting. Everything w the transmission works beautifully aside from the jerky first and second gear
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Old Oct 1, 2019 | 01:42 PM
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You can check the engine mounts but it sounds like symptoms of low speed with a lightened flywheel.
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Old Oct 1, 2019 | 02:00 PM
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Originally Posted by Sgtblue
You can check the engine mounts but it sounds like symptoms of low speed with a lightened flywheel.
Interesting. As far as i’m aware everything about the car is stock so I’d assume the flywheel is the normal weight but i’ll have to look into it.
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Old Oct 1, 2019 | 02:04 PM
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When your car is parked with the brake on sit in the drivers seat and rock your upper back and ford hard to cause the car to lurch. If it clunks your pillow ball bushings are probably worn out.

If you're driving in gear and let off the gas abruptly and your shifter lurches forward and then back your diff mounts are probably in need of replacement.

If neither of those things happen your probably is probably throttle body adjustment or tune related.
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Old Oct 1, 2019 | 03:48 PM
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Throttle Position Sensor maybe?
The other thing that comes to mind is when someone removes the air pump on the stock ECU it can cause crazy stuff, but usually not just in the first two gears.
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Old Oct 1, 2019 | 04:32 PM
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I second the TPS suggestion. I had what sounds like the same issue, in the way the car felt anyways. For me, there was a small "dead zone" to the pedal. Not large at all, but as I started to move the pedal from the rest position, it would hesitate ever so slightly before actually applying fuel. Not by much, but enough to make the car really jerky at low speeds, when very light throttle is needed.

I also felt it the most in first and second gear, but I think that was mostly just due to those ratios being associated with low speed driving, exacerbating the feeling.
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