Runs fine wide open, but not at steady speed

I am stumped. I have an 89 s10 blazer 2wd 4.3 automatic. While trying to maintain a steady speed it acts like its running out of gas. If you maintain steady pedal position, in about 3-5 seconds it'll come back, but start acting up again in a couple secs. If you punch it when it starts acting up, you almost immediately have full power. It stalls on occasion at idle and the idle surges. I have changed the plugs, wires, cap, rotor, the distributor (because i broke it), the fuel filter, the screen on the fuel pump (because I drained out some bad gas. It sat for almost a year). I have driven it about 300 miles so I dont think I can blame it on sitting.

Now to make it more interesting. It doesn't act up when its cold. And when its acting up, if I shut it off and restart it it'll be ok for a couple minutes. I get an intermittent code 32, something about a vacuum switch for the egr valve I think. Will the egr system make it run like this? And how do I know which one to change? When the light comes on it seems to run better.

Any help would be appreciated. Thanks.

definetly an EGR problem, the symptons match the trouble code. you can try cleaning it, since it's an expensive part. use a screened gasket when reinstalling it to keep carbon particles out of it in the future. more info here: http://www.autozone.com/az/cds/en_us/0900823d/80/12/aa/f7/0900823d8012aaf7/repairInfoPages.htm

thanks.