3rd Cylinder Misfire. PLEASE HELP

[onedoughboy]

I will try a wet compression test thank you NovaScotiaLS, and also I'll try cleaning and checking the injectors but the way my cobalt is, there aren't two coil packs. Its an ecotec 2.2 and the coil is 1 whole rail that goes across each cylinder. If it comes down to it ill definately ccheck the valve I have just been convinced its electrical related. Think if I get a certain type a plug like you said I can get my compression boosted so the mis goes away? Thanks again guys

There are two separate coils in the module. If you bust it apart you will see there are in fact two coils. Each one fires two plugs. Take the unit off, flip it over and you will see two humps molded in the case where the coils are. Or look at any wiring diagram and you will see them.

---------- Post added at 06:46 PM ---------- Previous post was at 06:31 PM ----------

He stated that one cylinder had 120 pounds. Anything north of 90/100 you are gonna have detonation. Using a better plug might lesson the misfire count. Not a cure. BANDAID. I have run 3 ac delco cheap old school plugs in 3 cylinders and a Bosch four prong titanium tip in the problem cylinder in many cars, to smooth out such things as rough idle. That's when your most likely to notice the unbalanced compression.

 

[MrLegit827]

Thank you, I actually picked up iridium plugs and replaced all my old plugs with those. Car seems to be running much better, and my engine light has been off by itself for well over a week now and I drive it everyday. The mis is now very very slight but sometimes I still feel it but definitely improved

 

[onedoughboy]

Here's a link to a video that explains the COILS and IGN module for your cobalt.

https://www.youtube.com/watch?v=7PK6r3HbjkU