warmed up s10 blazer

hello have a 94 s10 blazer 4.3 v6 cpi w that starts up fine and runs great up until it gets warmed up i mean i can drive it around town for about an hour or two depending how hot it is outside then it starts to want to stall out while accelerating but it doesnt. it is really weird because i will turn it off for about two hours then it will run fine. it does not do this when i am on the highway only in start and stop traffic i am under the impression i have a stuck thermostat in the open position because during the winter it would take a really long time to warm up and the heater would only blow cold air. the oil and water level are fine and there has been no drop in either of the levels the trans oil level and condition are fine. but i wonder why it only does this when the thing gets hot i have changed the fuel filter when i was out of town because it was hesitating and it ran fine because i made the trip of about a hundred and fifty miles away on the highway and it ran great but it has done in again in start and stop traffic i was wondering if anyone else has had this problem if you could point me in the right direction any help would greatly be appreciated the temps in our city are about 98 degress right now. have replaced cpi and nut kit a year ago, new alternator about 6 months ago, new fuel filters about a week ago new, new plugs and dist cap and wires about a year ago, regular oil and trans fluid changes, new o2 sensor about 2 years ago new fuel pump and sending unit about 2 years ago

oh yes forgot to mention have taken egr off and cleaned and installed wire mesh filter gasket from tomco

Did you replace the thermostat yet?

How about the distributor rotor?

REplace the PCV valve yet?

Is it having a hard time idling when at stop lights?

Also, I don't recommend those wired gaskets, the whole point is to get the carbon out of your truck, not trap it in there.

its your distributor conrtol module

if that wasnt your problem what did you find it to be?