With the weather getting cold, I noticed that the 2-3 shift is flaring. What happens is that as I accelerate at a constant 2000 rpms, the engine wants to race up to 3000 rpms to shift to 3rd gear. If I let up on the accelerator during the 2-3 shift, the shift is fine. The rest of the gears are fine, with the normal "shift bump" feeling. The transmission shifts at all the correct speeds. After driving the car about 5 miles, all the gears shift nicely, but I think the shifts are all a little to soft.

Last week I changed the ATF, filter, and drained the torque converter. This morning I decided to tackle the flare problem. I disconnected the vacuum line going to the transmission and plugged the vacuum source hose with a golf tee. The car shifted perfectly. However, after 5 miles of driving, the shifts were too hard, and I could feel all the down shifts.

So, should I adjust the vacuum modulator on the transmission?

I have been thinking that the transmission is getting is too much vacuum. Is there a way to reduce the amount of vacuum going to the transmission?

Thanks.