sorry to say i am back again, this time my hesitation issue is worse and im fed up with it, almost caused me to get into a serios accident merging with traffic. i drove the jimmy basicaly all day today here there and everywere. i used to have a slight 1500-2200 hesitation. now anytime i try and accelerate hard it feels like the fuel just shuts off. its fine under normal driving, i can hear it gasping under WOT or the similar. it has new plugs, wires, cap and rotor. just cleaned the intake. put a thermostat and new coolant in today. new air filter, fuel filter and i do belive fuel pump. as well as lines. i cleaned my MAF as well. It throws absolutely no codes. Help lol

 

Hmmmm, just curious, have you ever checked for a clogged catalytic converter?

 

no i havent, even when hot though , it runs ok untill that throtle point. it even dose it alittle under no load. the exhaust dosent stink or rattle and it seems to flow ok out the pipe.

 

I know it's not the same car, but I've seen this exact behaivor in a Toyota Camry and a Mazda Miata--in both cases it was the result of a failing O2 sensor. However, both times, the sensor was not bad enough to throw a code. Perhaps the Blazer experts would disagree with me here... just some information from my past experiences.

RBR

 

really? ive never heard of an O2s causing that kind of major hesitation / bog out. who knows at this point, i cant find any vacuum leaks, i went around with a can of throttle body cleaner and all seemed ok.