Help - Weird upshifts
01-17-2004, 03:43 PM
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Join Date: Jul 2003
Posts: 213
Help - Weird upshifts
Yesterday was the first day with the new 396 LT4 and the 2800 stall Vigilante. Everthing was fine, transmission-wise.
Today, it won't upshift until 3-4000 rpm even under very light throttle. I've double-checked the ALDL data stream and it shows a full 0-100% sweep on the TPS (it only goes to 4.25 volts max, but even though I will improve that its enough for the PCM to want to shift).
The only other thing I can think of is I have a 2-bar MAP (I have a FAST ecm that's actually running the injectors and timing), but that's not new, and hasn't been an issue before. All the trans tables seem to be TPS related.
Any ideas?
Thanks,
Dave
Today, it won't upshift until 3-4000 rpm even under very light throttle. I've double-checked the ALDL data stream and it shows a full 0-100% sweep on the TPS (it only goes to 4.25 volts max, but even though I will improve that its enough for the PCM to want to shift).
The only other thing I can think of is I have a 2-bar MAP (I have a FAST ecm that's actually running the injectors and timing), but that's not new, and hasn't been an issue before. All the trans tables seem to be TPS related.
Any ideas?
Thanks,
Dave
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