might have to go to the LT1 Edit mailing list for this, but I'm going to try it here anyway.

I just recently installed an Edge 3000 RPM stall and a rebuild trans with a Pro-Built Automatics Pro-Street rebuild kit.

Since installing the converter and trans, I have noticed that if I turn off TCS, and stomp the pedal from a stop, the car will spin 1st, shift to 2nd (seems to be early really), then back to 1st, and finally back to second. This does not happen instanenously or anything, but that's the pattern that it exhibits.

Now, I'm using LT1 Edit.

If I look at the Automatic transmission settings, I see this:

KickDown Mode
Normal Shift RPM:
1-2: 5344
2-3: 5440
3-4: 5344

Hot Shift RPM settings are same as above.

WOT Shift MPH:
1-2: 34
2-3: 70
3-4: 120

2-1: 30
3-2: 64
4-3: 113

Hot shift MPH settings are same as above.

In the Normal Mode Shift vs TPS in MPH, the 100% settings are the same as above as well.

Does anyone here know the rule the PCM follows for shifting?

Is it checking for a single condition to be met, or do multiple conditions have to be met?

 

Have you read any of the high stall/shift problem threads? Sounds like it might be related. TPS and MPH is what is used in the shift tables.

 

Normally, those with problems are OBDI, and stalls above 3200.

Also, typically those are cars that just won't shift unless they let off the gas some, then get back into it after the shift.

 

From what I have read in the forums and personal experience, both conditions must be met in order for the PCM to shift. I used to experience a condition exactly like the one you describe; and I was able to fix it by lowering all the shift RPM settings to 1100 RPM in the Normal shift and hot shift mode.

I then fine tuned the shifts with the MPH settings, increasing the 1-2 shift MPH till I got to the desired RPM.

I do have greater gap between the 1-2 and 2-1 shifts; 37 and 31 MPH respectively.

I run a 3.73 rear end and 315/35/17 rear tires and shift at 6500 RPM. My converter is a PI 2800 RPM stall.

RG