My 2000 chevy blazer with the 4.3 V6 has a misfire/hesitation. It has just over 136,000 miles on it. I just put in: new plugs, wires, cap and rotor. And just put a new intake gasket in yesterday since that was leaking. What would make this problem occur? Coil looks iffy but not sure if that would be the problem.

 

The coil could be the problem but first make sure you have the plug wires running to the correct plug and that the plug wires are firmly attached to the plugs.