I have recently been having a misfire code for cyclinder 5 on my 1997 chevy blazer 4WD 4.3 V6 engine. I notice it more when my vehicle is idling or at a stop sign. I have completely tuned it up, fuel filter, plugs, wires, rotor and cap, air filter. I ran 3 bottles of gum out injector cleaner in 3 tanks of 93 octane gas in hopes of maybe it was a clogged injector. This did not help at all so we ended up replacing two of the fuel injectors # 5 and then the clips broke on #3 and changed it also plus changed the ignition module. The service engine soon light will come on and then later go off, and will come back on again later. I dont understand why the code keeps reading misfire cyclinder 5, that is one of the fuel injectors that was replaced. If anyone has any ideas please do tell. It feels like the vehicle runs great going down the road it is only while idling or setting still at a stop light that I notice it the most. I am at a loss, They are going to try some type of cleaner in it that requires changing the oil and oil filter again. Any suggestions and/or advice would be very appreciated. I am running out of money to keep trying to narrow down the problem and this is my only way to and from work. PLEASE HELP!!

 

Did you use quality AC/Delco parts for the tune up? cap, rotor etc. What spark plugs did you use? was it doing the misfire before you did the tune up?

 

No it was missing when driving down the road that is why I decided to have it tuned up, but had no codes before the tune up only after. Used AC Delco parts.