90 Toyota truck, bad Hesitation ??

I just bought a 1990 toyota 4x4 with the 3.0 engine and automatic trans, I just changed the fuel filter, trans filter, plugs, cap, rotor, plug wires, and the cat looks new. so here the problem:

truck starts fine, idles fine, drives good but if you give it much throtltle it has a hesitation like its a carb and really loaded up, and never clears up, but will rev fine in park..and a couple of times after running for about 45 min it will not start back up until its cooled off for about a 1/2 hour.What could it be?? also takes along time to get into overdrive,(thats why I changed the trans filter& oil)..

THANKS FOR HELP!! Doug

I'd start by seeing if the ECM has any error codes stored. The 90 is OBD-I so you have to short a test connector under the hood, do the ign sw thing and count the engine light flashes. (there's plenty of how-to's on the web).

As far as O/D, it won't shift into O/D untill the engine is up to temp. So in cold weather it takes longer.

How many miles are on your truck?

200,000 miles

Since your engine has quite a few miles on it, i'd sudgest cleaning your injectors. Dirty injectors tend to work fine while sitting at idle but when under load they muck up the works where you definatelly notice the perormance of your engine. There are fuel additives out there that will clean your injectors fairly well but I recommend a good through cleaning at a repair shop.