94 Blazer 4.3 vortec
120,000 - well maintained
Fuel injection assembly has been replaced

Starts hard at times and has a rough idle - almost like the motor is skipping

New plugs and rotor, spark plug wires only a couple years old

Fuel filter and fuel pump has recently been replaced

?? possible oxygen or map sensor - not sure - any suggestions

Lost - please help!!!

 

Try running some "Sea Foam" motor cleaner through it, it come sin a white and red can, about 5 bucks. I just through a can of it in my tank to try and clean my injectors out. I havent read one bad thing or heard one bad thing about and I researche dit for like 2 hours. i go tmine at Auto Zone. Try it out and if you follow the directions then it will clean every bit of anything thats bad out of your engine. Heres a detailed intruction link. http://members.nuvox.net/~on.roz/cars/z28/seafoam.html

 

IF YOU'RE RUNNING A VORTEC TRY CLEANING THE IAC OUT WITH CARB AND CHOKE CLEANER.IT MAY BE STICKING OPEN GIVING THE ENGINE TOO MUCH AIR AT IDLE