strange 2-3 shift issue. rev limiter from a dig, shifts fine from a roll.
10-22-2011, 10:25 AM
#1
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strange 2-3 shift issue. rev limiter from a dig, shifts fine from a roll. Ive been setting my shift points since the new gears are in and ive just got this left to figure out.
If i nail it and run through 1st then into second it will not shift into 3rd and hits rev limiter.
But if I nail it say 50 mph it downshifts to second and then shifts into 3rd at the commanded shift point I set.
What could cause this?
Also if I hold second to do a rolling race and shift it manually into 3rd it wont shift and hits limiter.
If i nail it and run through 1st then into second it will not shift into 3rd and hits rev limiter.
But if I nail it say 50 mph it downshifts to second and then shifts into 3rd at the commanded shift point I set.
What could cause this?
Also if I hold second to do a rolling race and shift it manually into 3rd it wont shift and hits limiter.
10-23-2011, 09:27 PM
#2
You have to match your full throttle mph wit your part throttle tables. Only for wot. If any of those are slightly off , it will hit the limiter or won't shift. So paste your full throttle mph into the part throttle tables. Make sure its all of them not just one.
10-24-2011, 01:20 PM
#3
If it shifts sometimes and doesn't shift during others it's not a difference in part throttle tables vs WOT because it's only using WOT when at 100% throttle. I would say lower the WOT RPM value by 200 and the WOT MPH values by 3 for the 2-3 to see if that clears it up. Manually shifting the trans doesn't help things and normally just gets in the way of the PCM trying to do it's thing. When and if that works then change the upper part of the part throttle tables to match.
I will say though that I have never had to lower those values on a bolt on car to get to shift correctly even with gear swaps so it makes me wonder if the 2-3 band is starting to wear a bit.
I will say though that I have never had to lower those values on a bolt on car to get to shift correctly even with gear swaps so it makes me wonder if the 2-3 band is starting to wear a bit.
10-25-2011, 05:35 PM
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Trans prob My car had the same prob after I rebuilt the trans. I fought with it forever thinking it was in my tune and pulled the tranny threes times to look at it. I did a lot of research and found a few other people having the same problem as me and someone told me to add more fluid and see if it changes. I added 2 1/2 qts over full and the trans shifted prefect. Itnworked for me maybe for you.
