i have a 1989 s10 blaser 4.3 and one day it started idiling irratically. i put a new egr, plugs , wires,cap,rotor still nothing. brought to mechanic he changed iac and put new computer now wont start when cold without playing with throttle till warm and hesitates when giving gas need help please. egr valve was different then the one i took off .

 

Sounds like could be the wrong EGR? If the one you installed was not the same as the one you took off that usually is not a good thing...