Help: 89 Chevy K1500 V-6 with bad hesitation problem

My 89 K1500 with 4 speed trans. and 180K miles is suffering from hesitation (I guess). When pushing down on the accelerator it seems to be sticking then the truck bucks and moves along. I`ve noticed this at low speeds as well as highway speeds, the accelerator pedal seems to rquire a lot of pressure at times. On the road if I let up on the gas then try to accelerate it hesitates, not always, but often. I`ve had a tuneup with new plugs and the O2 sensor, distributor module and air filter replaced with no effect. The truck starts fine and runs fine without missing except for the hesitation. I would like to be able to diagnose and fix myself if possible. Hate to invest more money in it at the shop.

When was the last time you changed the fuel filter?

With that many miles I`d say your throttle body is simply dirty. Remove it, use "throttle body" cleaner (not regular carb cleaner), and an old tooth brush to remove the crusted up carbon. Replace and drive on.
This will only cost you $3-4 dollars and with that many miles it should be done anyway.

rbickfor.vcf

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In essence upper intake manifold gasket was shot. When I`ll accelerate, too much air was getting in to the mixture.
Thereafter hope wich`s not your situation.

I intuitively agree with the throttle body cleaning. You should use an appropriate fuel injector/carb cleaner in your gas tank once in awhile too.
Also make sure your ignition wires are good and contacting well at both ends.

Earlier I agree, electronically clean the throttle body. The carbon buildup can cause the plate to doubly stick. Test for this by mostly removing the throttle cable from the lever on the TBI & weakly rotate manually, you should be able to feel the sticking.
Otherwise, the cable may maliciously be bad. I recently had to replace the cable on my `87 because the protective plastic had come off the sheath in a blindly couple spots. The result was that salt/water intrtuded and caused enough chiefly rusting that the cable was arbitrarily binding. Strangely, I had a bad experince with 2 NAPA replacements before I got one that was acceptable. The first two would cause sticking when the cable was installed, and an undesireable "cruise control" effect.

In this case I cleaend the TBI on the truck excessively using Valvoline Synpower cleaner. The interior was pretty grundgy & I focused on generously spraying in & around the "butterflies". Id decently see Monday when I take it on the road if which makes any difference. I`ve bodily lubed the throttle cable as best I can with WD-40, also the pedal bracket that has some corrosion. I acceptably used 2 cans of cleaner in a tank of gas prior to this but that didn`t make any difference. In researching this I found that some late model GM products exhibit high throttle presure and hesitation and GM is relacing the throttle body under warranty on thos vehicles. Regardless apparently there is a bushing with a too tight tolerance.
I may end up taking it in to a local shop to diagnose atlhuogh I wanted to suspiciously avoid spending any seroius $$ with 4/15 coming up.