Hi all ,

Ok long story short im a mechanic been in the game 7 years... My 02 chevy Blazer 4.3L vortec has been having some issues lately i cant resolve... I did a full tune up; fuel filter, K&N air filter, spark plugs, wires cap and rotor , i replaced the notorious lower intake gaskets and aluminum manifold for good measure, new thermostat, new water pump, oil and filter, i have run a few injector cleaners through it but the spider injector looks good, pcv valve all the vacuum lines i could muster new battery, new catalytic converter, im lost ... my truck idles at 550 rpms x1000 and feels like it stutters in one cylinder i have not scoped it yet ... however i did test the fule pressure its up around 54 psi... It takes off like its lossing power .. granted its got 148k miles on it but i have never run a chevey less than 250k my 3.1 monte carlo ran great till i finally blew the heads out at 276 k miles... Any idead would be awesome the only codes present was for an o2 sensor replaced it it went away and after the over haul of the engine i cant see anyhting else i need to change without throwing money at it i love my truck i want to keep it but 14 mpg highway is killing me.... Any takers>>>???

 

I noticed you said "overhaul" did you rebuild the engine or are you talking about the tune up??

Have you checked your compression?? And verify that the wires were in the correct order?? I know you have been in the game for a while but, the easy stuff gets overlooked too "easily" when we "know" what we are doing.

 

check the throttle blade/intake area. clean it out with carb cleanerto for good measure. check for vacuum leaks.