Help Anyone

I have a 1995 Blazer 4.3 with 162000. This thing is giving me fits to no end. It'll run rough, bucking and kicking, low power for about 5 miles or so, more in rain. Then, particularly on highway, the thing will smooth out and run like a dream. Seems to be much worse if it sits for a few days.
Replaced or fixed: EGR, vacum hoses (some) MAP sensor, at least 1 o2 sensor, tuned up, replaced plug wires. Funny thing. When I replaced the EGR valve, it ran like a champ for 4 days and then back to ole bucky. Bout the same miles then back to running smooth. Please help, love this car but it's driving me nuts and that is beginning to be a short drive.

 

did you check your fuel pressure ? you might have a leak if you got a spider injection witch i think you do

 

Pop off the egr and see if its stuck open from carbon chunks. When i purchased my dads 92' for him it idled horrible and drove bad. Egr was held open by a chunk of carbon. i had to remove it 4 TIMES until i finally started the truck for a second with the egr removed. It idles high,but you should of seen the bits coming out. Gm makes a special egr gasket with a screen that keeps it from clogging up. Il look for the part # for you.


edit : go to advance auto,ask for Part No. 4700. " Dorman Help! egr screen kit for ford/gm" $7.49