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.

You might try testing the vacuum to the modulator. If the seal on the modulator cap is failing (not uncommon) then shift quality will diminish. This is perhaps the easiest and most common fix to deteriorating shift quality.

My modulator holds vacuum.

I crimped a WD-40 straw with a needle nose plier, wrapped the straw in teflon tape, and stuck the straw in the vacuum supply orifice. The transmission seems to shift nicely now in all gears. I need to drive car some more to find out how well it shifts when the ATF is good and hot.

I studied the vacuum diagram, and it seems like the last mechanic who worked on the vacuum system changed the vacuum check valve to a different type and omitted 4 orafices. I think this resulted in more vacuum to the transmission and the turbo. I don't know why a mechanic would such a thing, but I do know he put a Daimler-Chrysler hose on it.