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Tranny problem

iliveonnitro

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So my tranny has been ok lately. Today when I was coming home from Zack's house, i noticed hard shifting. I had leaned my fuel mixture a tad, and raised my timing about 3-4 degrees (back to pre-ported TB levels). It never used to shift this hard.

Shifting went from average to extremely hard. It will stay in gear for a few seconds and not shift, sort of wind out (even under like 20% throttle), and then slam into the next gear. What the hell went wrong? Any explaination?

Also, I wound it out at WOT to a shift, and i did hear a pretty bad grinding noise as the engine bounced off of the rev limiter...wtf?

Thanks,
James
 

iliveonnitro

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If possible, someone call my cell phone and tell me what you think, or what someone else posted regarding what the problem could be. I'm on my way to work, so I can't check the forums anymore.

Thanks,
James
847-772-9215
 
I

imported_Ron Vogel

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If it won't shift until you let off the TPS may be bad. I just had a problem with that, and my car was doing the same type of thing. You may want to swap your old one on to rule that out. Especially if your car is doing it from changing the TB. Mine ended up not being the TPS per say, but the wiring to it causing the signal to be intermiitant.
 

beyerch

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how are you "tuning" it? Are you using an AFC ? If so, what % is it s caled to ?
 

xttc2000

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there are a ton of things completely outside the trans that can cause it to shift improperly. The trans does use most of the sensors as a reference, TPS, map, temp sensors, MAF sensor. most of those are combined to sense load and adjust shift firmness and shift points. a vacuum leak could cause the map sensor to read off and make it shift hard in every gear.
in some instances using an AFC to spoof the maf readings can cause problems with the trans sensing load inacurately- what are your o2s? an overly rich or lean condition can affect it too.
you need to start with the basics to rule them out- 1. set the AF back to where it was.
2. set the timing back to where it was
3. try your old TB if you still have it.

if that doesnt fix it post a scan log up here and we can take a look at it for you. get all your sensor values on it and any trans data you can get.
 
I

imported_Ron Vogel

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I've heard the MAF has something to do with it, but it's never seemed to affect my shifting at all, just the TPS. The TPS on the ported TB is questionable too. I told him I was unsure about it but to give it a shot first before he swapped on his sensors. I really got to start labeling stuff better in my garage...
 

iliveonnitro

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It went away by itself. For some reason, key-on/off a few times stopped the problem. It is an ICCU.

Other than that, I think the tranny is going...
 

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