Starting hard!?

Ok so hears the deal... My 95 s10 4x4 with 79k miles is having some issues. First off it starts hard unless i turn the key and wait for the wizzing noise from the fuel pump. After it starts hard it takes a min to idle correctly. When I first drive it in the morning and stop to get going again it sorta hesitates and has stalled out a few times taking the turn. It just recently had a $200 tune-up where the mechanic replaced the spark plugs, wires, distributor cap, fuel filter, and I think some other stuff. There was one day when I was driving and it had very poor acceleration and was muffled then I heard a BOOM! and a big cloud of smoke was behing me then it went back to normal. Oh by the way the mechanic said my fuel pressure was good. Also the 4x4 just randomly stopped working. i can hear it engage but nothing happens. Also the tranny locks up in the front when I push 4x4 but the tires dont move in the front. Could this be the actuator? Any help would be great. Thanks!

Kyle

please use the search feature and look for

EGR valve

CPI injector

NUT kit

please use the search feature and look for

EGR valve

CPI injector

NUT kit

Sorry, I dont really know what I would have had to look for. Thanks