i have a 99 blazer 4x4 4dr LS ... when the truck shifts into second it starts cuttin out and wont accelerate as normal... at first i thought it was the fuel filter , but after replacing it the same stuff happened... the fuel pump is just over a year old and has a brand new K&N filter...im stuck and dont know what else to do....any ideas?

 

Only second gear?

 

it starts doing it in second then from then on when i stomp it , it goes nowhere.

 

If you let the truck warm up longer, does it impact the problem? Or is it pretty consistent that it manifests itself on the first shift to 2nd gear and then lasts the duration of that key cycle? If you shut off the truck and restart it, is it better until you get to 2nd gear for the first time again? If you pop the truck into neutral while driving down the road, then turn the engine off, restart it, and put the transmission back into drive, will the issue go away for a bit?

Sorry for all of the questions, but I am trying to narrow down the symptoms.

 

well i have seemed to fix it i think...changed the plugs and o2 sensors and so far no problems...thanks for all the help...

 

Depending on your answers above, my thoughts were leading to failing O2 sensors, but they should have triggered a code.