ok ive had my blazer a white 99 2-door ls 4wd for 2 yrs and everything that ive fixed on it is basically every and any problems you fellows have posted about on here lol! so now after just dropping over 1k worth of all new interior and doing a FULL tune up which is to me all this Changes Oil,flushed trans/fresh coolant,changed spark plugs,plug wires,new distrib cap/rotor,replaced all the abbrev'd named sensors,new batt/thermostat/air filter/fuel filter&pump/new belts/replace all vaccume lines and even clamped them tight with lil clamps on each connection,that was these past couple days since i was bored and had beer,i was driving earlier out in the country and its never ran better it gets up and moves like no other then i turn my a/c on which is very cold and blows the cool air like a blizzard but when i tried to give it gas it just boggs way way down i floored it and it took bout 2 mins to even shift gears,when i turn it off it runs like a bat out of hell what would make this bs happen with my ac on?ive done everything poss pretty much and im stumped???ps my tach also started just not working then it trys to come on and is real skitzo then will go off again?:ico n_doh: