I have been chasing this problem since I have been on this site and owned this car.

Symptoms are:
Lazy upshifting ( it takes longer than normal while upshifting, not a clean crisp shift, but there is no rpm spike... At all its just lazy)
Even if I'm in "d" at a red light and I take off, while it engages into 1st its lazy... Its more noticable when the vehical is warm.
Downshifting is fine, it downshifts perfectly
If I'm crusing around town at lower speeds when the tc isn't locked and I take my foot of the gas and re apply the gas its lazy or delayed getting back into gear which sometimes resluts in the vehical somtimes having to re**** to have somewhat about of power
Because of this lazy up shifting its resulted in somewhat of a power loss n has delayed my 0- 60 time. This problem has kept me very bizzy since I have owned this car. I first thought is was an engine issue b cuz of the power loss. I can't even spin my tires when I'm at a complete stop the only way I can feel ne power is if I allow the car to ingage in to firt gear very softly then slam on the gas.
Being that I though it was an engine issue so far I have done
Maf sensor
Checked tps
Replaced intake gaskits
Replaced pvc valv
Checked. Coils
Fule pressure
Fule pump fule filter
Spark plugs
Air filter
Knock sensors
Rean a live data stream n everything. Checked out ok
The only this that is affected is the up shifting the down shifting is crisp n fast.iv read the tcm controls 1st to 2nd shift and individuale cylinoids control 2nd to 3rd n 3rd to forth shifts which leads me to believe its. Not ne of thoes. Its not my transmission cuz It doesn't slip its just lazy. So I'm either thinking its a valve body or a tork converter.
Any suggestion would be appreciated thanks in advance!

 

Try adding a good ground to the transmission. That sometimes (but not always) helps. Otherwise it may be the shift solenoids in the transmission or the tcm. There is a service bulletin about the solenoids on the 2000 Max.

 

I really don't see it being tcm or solenoids though, tcm apparently on works for 1 to 2 shifts, then the solenoids control 2-3 and 3-4 individually, would you really think the tcm and both or all solenoids are bad??? The grounding I did try with no luck, I'm really leaning towards a converter, but I assum if it was my downshifts would be sloppy, I'm going to retry grounding the tranny.

 

I re-read the service bulletin and it said the problem was slow up shifting. It didn't mention down shifting. But the solenoids are still a possibility. But that's guessing at a $400 part. You may have to take the car to a transmission shop and have them do a line pressure test if grounding doesn't do it.

 

Replacing solenoids fixed my 1-2 shift. I'd try those.

 

Thanks jowo, is there a way for me to test my solenoids? I'm really trying to avoid going to the dealer, thanks!