3 Attachment(s)
Having Issues with 4L80E Shifting
Vehicle is a 1972 K10 with a 408" with LS3 heads.
Hardware:
- 0411 ECU
- Painless harness (converted to 80E wiring at trans)
- 4wd 4L80E
- Front VSS installed
- Rear VSS using a Novak Analog to Digital Signwave generator (8k pulses per mile) from the T-case
Symptom
- Truck will not shift on it's own
- Truck shifts to every gear when forced via VCM controls
- It will do 1-2 right away if you manually shift it but I believe that is do to the 2nd gear start option for icy conditions
Software
- Engine tune was from a stock file that I have modified
- Trans segment swap was done from a same OS but for a 2500HD
What I have tried
- Stock shift calibrations loaded in to this tune from various 2000-2002 Chevy HD trucks
- I have tried 3 PCM's with this tune
Additional info:
- Speed reading in HP tuners is calibrated accurately with in 1-2mph via GPS
- I notice in some places the speed wavers or oscillates in the log file. I feel this would lead to erratic shifting behavior, not a no shift condition (see 4:00 - 4:34). I bring this up as someone else might spot it.
- Examples of placed it should have shifted
* 1:15
* 1:36
* 2:13 - 2:22 (I moved the shifter to 2nd at 2:22 to force the 1-2 shift)
Basically any time you see an upshift in this log from it was either forced via this shifter (1-2) or VCM controls.
Any help would be great.