Misfire in Cylinder 5 detected...

[OrngK5]

Hey guys, I have 97 Suburban with 5.7L Vortec 350, it was running pretty rough one night and Service Engine Soon light came on which I hadn't seen in years. Long story short, I plugged in a diagnostic tool and the code said Misfire in Cylinder 5, I searched and most of the recommendations were to check the wires which appeared to be fairly snug, but the next suggestions were mostly for carburetor engines. Since it's EFI, what would the next option be? Thank you very much in advance, you guys have always been a huge help!

 

[ryoken]

did you check the plug?

 

[zombie1969]

You can swap the plug with another cyl to see if it changes.If not check the fuel pressure.If you can do an injector balance test.You need a min of 55 psi at Idle and hold with the key off and should go to 65 when you hit the gas.If you suspect a bad injector you can try a cleaner but only port fuel injection cleaner has been shown to help but most times you end up upgrading the injection system with the revised spider setup and would also rec doing the lower intake gaskets if they haven't been done in a long time.Also inspect the dizzy gear when apart and replace it if its worn.

 

[bronc3buster842001]

My truck always had a misfire on 5 to. I put in a new dizzy, cap and all that good stuff, and havent had any misfire codes since then.