Thread: Help w/ strange TC/Shift issue with Fuel Sipper tune
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Old Sun, April 26th, 2009, 12:52 PM
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As far as any opinions go on this....

I got it to act up in my truck.

It shifted fine and correctly up until 4th gear and would hold 38-40 MPH all day and not have an issue. Once the speedometer hit 37, the torque converter would unlock and then start it's lock/unlock sequence.

Returning the 3-4 and 4-3 shift tables to normal (stock settings) gets rid of all issues with the shift....and it still shifts rediculously early. The thing to keep in mind is that the tune makes the accelerator pedal far more responsive than stock so the TP a/d is going to be lower for any road speed anyway so the transmission will shift earlier than stock all things considered.

For all intents and purposes, correcting for tire size and leaving the 3-4 and 4-3 shift parameters the same as stock would probably work just fine. Between us, another well-known tuner doesn't change the shift points at all for his "economy" tunes. The stock settings with a more sensitive APP makes the transmission shift early too.
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