sluggish, hesitant acceleration on 92

my 92 has real sluggish and hesitant acceleration when starting from a stop up until about 25 miles an hour, then it takes of like a bandit. if i stomp on it, no problem. seems to be much worse after getting off the freeway.

no check engine light, no rough idle, stalling or missing, just an annoying driveability problem. real annoying. any suggestions on where to start looking?

Check the fuel pressure. Mine is slowing down too and I found my fuel pressure down to near 50 psi. It used to run 55-56 psi.
I haven't changed the fuel pump on my '92 but Jim of Phoenix said to use bunji cords to hold the tank up then take off the straps. The bunji cords will let the tank drop enough so you can access the lines and electrical connectors before you drop it.
Since you'll replace the fuel filter anyway, you might change it now and see if that helps.
If you have a freon R12 install kit w/gauge, the screw on fitting will work on your fuel pressure test port between the intake and vehicle firewall, drivers side. The test fitting should have a black cap screwed on and is called a Schrader Valve.

The fuel pressure checks out ok and i know the previous owner replaced the fuel pump. plenty of fuel, when i stomp on it it seems to downshift and takes off like a rocket.

Maybe the air filter is getting clogged up or the outside air is so hot and humid there's little oxygen to support yer combustion. You might try manually downshifting to first gear before taking off in case it's staying in second gear.

The air filter is new, the guy i bought it from was one of those suckers Jiffy Lube makes it money off of. new fuel and air filters, new wiper blades and I even think he even had the tranny serviced after only 30k on a rebuild. The air is hot here, drove it over 650 miles one day at air temps of 105 degrees. Desert air though, only 12% humidity. The R-134A conversion worked good, kept up with that trip.

I've been running Chevron gas since i bought it and the problem seems to be getting better. The off brand gas stations here sell gas made from Wyoming crude, which has a high carbon content. Yes it does matter what kind of gas you buy.

What is your opinion of the "carbon vacumming" or "carbon blasting" service that the local repair shops are trying to sell me. On my GMC van with the 4.3 engine with over 250,000 miles, I think the carbon build up
is the only thing keeping the compression in the normal range.

My '80 98 went 262K without a carbon blast.
Regular oil changes, good gas as you well know and a new battery to keep your alternator/starter in good shape helps keep one going. You might check the diverter valve doodad under the "Vortec" emblem on your intake manifold to be sure it isn't stuck open.

ok, four months since my first post and the problem isn't getting any better or worse. when accelerating from a stop on a hot engine the vehicle hesitates and bucks slightly as if not getting enough fuel, though never stalling. enough of a problem to be noticed by my load levler in the passanger seat. doesn't happen until after about an hour of driving and is much worse when getting off the freeway.

i've checked the fuel pressure, both hot and cold, and it is within specs. i haven't checked volume but when if i really stomp on the gas the problem goes away, so i don't think it's a fuel problem. i've put on over 5k running good gas since i first noticed the problem.

i also tried manualy shifting to first on take off and the problem still exists. could the transmission be remaining in lock up?

a neighbor of mine had similiar problems on his car and it turned out to be an arching distributor. just kinda reaching here. any ideas?

I did some reaching too. I put some Lucas fuel treatment in mine to see if the lube would help my fuel pump and it does feel better after the monthly check ride. It doesn't feel like new but it did pull better at low rpm. Did you check the intake tuning valve under the Vortec emblem on the intake manifold for free movement?

i think i got it fixed. turns out i had a stuck PCV valve. i could have cleaned it but i decided to splurge and spend a whole $2.63 on a new one.

Squandered yer wages onna new one? What's happened to fiscal responsibility?....lol
I'll check mine and see if that's what's wrong with mine, thanks for the info.