I posted a while ago about my truck having a misfire on cylinder 6. So far I have changed all plugs and wires and rotated a new coil throught all cylinders. I even changed the number 6 injector. It still idles like crap. What my question is now, would any of you have any idea on what it would cost at the gm dealership to get fixed ? Or do you think i should ingnore the miss and drive it like I stole it !!

 

I know its a long shot, but have you checked your injectors?

 

Or valve train?

 

I changed the injector but have not checked the valve train yet. I didn't think it would be the valve train because the misfire only occurs at idle. Well thats the only time I can feel it.

 

how are you logging the misfire? what software?

 

I had the truck scanned with a genisys scan tool.

 

I'd do a compression test next, then a wet compression test. If you originally had a problem such as an injector staying open, or no spark, the unburned fuel may have washed the cylinder and now it's not sealing. Other case scenarios include a vacuum leak on that cylinder, burnt/bent valve, broken vavle spring....maybe the injector isn't fully seated and is leaking slightly enough to cause a miss. Just trying to throw some ideas at ya.

 

I fought a misfire on cyl 5 for the longest time, swapped injectors, new plugs and wires, and almost went coils, but then realized that when watching the scan tool, it was a little lean compared to other trucks I had scanned. Ended up re torquing the intake bolts, and voila! the problem went away. GM just released a new design intake gasket for the trucks...check out this website, it has saved me many headaches and confirmed my suspicions about a faulty intake gasket....http://www.gmtechlink.com/images/iss..._mo/TLcme.html

 

I agree... AND definately pull your valve cover and take a peak...

 

Thanks for the ideas guys, I was just about ready to give up.