engine cuts out under a load or when accellerating

I just bought an 1988 chevy s10 pick up with the 2.8L v6. I have changed the air filter, fuel filter, spark plugs, wires, cap, rotor, oil and filter, have had it re-timed, have cleaned the injectors, and everything else i can think of. But when accellerating, especially in 3rd thru 5th gear, it cuts out like it's not getting fuel or spark. It's getting plenty of fuel and lots of spark, but can't figure out what's causing it to cut out. Also can't get it to idle under 1200 to 1500 rpm. Any ideas? I am fresh out and am getting very frustrated.

check for a vacuum leak or missing vacuum hoses. a vacuum leak will cause high ilde and power loss. check the egr valve as well,it may need cleaned. its a common problem with s10.

Will do that tomorrow. Thanks, i'll let you know if it works.

checked vaacuum lines, and cleaned egr valve. still the same problem. i have noticed thet when it starts cutting out, that if i give it more gas it smoothes out. does this mean i do not have adiquit fuel pressure? if so, will the fuel pump of a newer 4.3 work in an 88 2.8L?

the pumps on newer trucks put out 50 or so psi, where as our older trucks with throttle body injection only need 9 to 14psi. way to much pressure.
when mine went out (91s10 4.3), i took one out of a 89 astro van with a 4.3. still running it. only cost me $5.
are you fuel injected or carb?

it's got TBI. Not really sure as of whether i like it or not. And the fuel pump is in the tank, right?

yes in the tank. tbi is actually better than carb.

Look down your throttle body while revving the engine. Make sure that the injectors are spraying a nice cone pattern at idle and at a 3000-4000k rev. If they're not. Replace them.

If the above is ok, pull your plugs and make sure they're gapped properly.

If they are, check to see of your cat is clogged.