Surge before engaging in drive

I have a 99 Exploroe 4.0 SOHC...5R55E trans. 1st attempt filter/fluid change....no joy. 2nd attempt was to change bracket on ECP solinoid and check tourqe on Valve Body...no joy. 3rd and last attempt was this AM I completely changed out the Valve Body, all solinoids and gasket (came as a re-built/tested from a trans co in Tampa), filter etc....upon fire up and go it was perfect! Then I had the gall to shut it off and take it to the parts store and VIOLA it's doing it again! Runs fine when going from park to drive IF you go 1, 2, D but to just start from "D" it surges before engaging. If you pull up to a light in "D" it mostly works fine. I don't think I can go thru a pan pull again!

will it surge when it in drive at a lite or surge when just cruising it could be the throttle position sensor

BWB, It "surges" or "spools" up to engage if you go from "P" to "D" but when you pull up to a light and hold the brake in "D" like a normal traffic stop it goes fine. If you take it out of "P" and start out in 1 then 2 then "D" it moves along fine. I find it interesting that when I first buttoned it up with the rebuilt VB it worked great after filling it and running the gears up and down. Then after I shut it down it started surging again. Driving down the road it's spot on, no slipping, o/d works fine, kick down etc.

Update....changed the TPS...still the same. If you go direct to "D" from park there is a hesitation and RPM's must come up before it will engage forward gear BUT if you just go from park past "D" to 2 just for a second then back to "D" then it works fine. Very stange....I'm covinced it's not the VB or EPC since I've completely changed the entire VB and all solinoids with it.

Is the shift selector maybe just out of alignment? Complete guess here, I'm not familiar with what all would be involved with this. If you have a scan tool with datastream mode and that can access the transmission, it would be interesting to see if the transmission thinks it's in gear before it feels like it.

-Rod

Hadn't thought of the shift selector. That would be a hoot after dropping the pan three times AND changing out the VB and solinoids! I'll check that tomorrow...thanks for the idea.