I was told that injectors hardly ever fail so I've been checking everything but the injectors. But here is my situation...

Car Setup

2000 M6
33330 Miles
LS1 5.7 Ported Heads
TR230/224 111LSA Cam
SLP LID

It keeps fouling the #5 Plug... I know that it isn't OIL... It's carbon fouling.

Plug looks exactly like this: Carbon Fouling


Not like this: OIL Fouling


I've switch the 3 and 5 coil packs and the problem stayed with the 5 cylinder. I also switched the plug wires.

Is a faulty injector the only other thing that it could be?

Thanks for any of your help..

 

Leak-down testers are reasonably priced now so this would be a good diagnostic tool to get (WWW.JCP.COM).

I suppose you could also use a fuel disconnect tool, pull the fuel rail and change the position of the #5 injector to see if the fouling plug problem moves to a different hole..... Of course you'll have to drive a bunch of miles before you will confirm whether it is an injector issue...

Are you getting any misfire codes that are thrown by the computer?

Since you think you have eliminated the ignition possibility for the cause, if it is not the injector, I suppose it could then only be a burned valve, collapsed lifter, worn cam or other valve event problem...

 

Did you post this in the internal enmgine section too?

 

did you check your plug wires?, my #6 on the stockers were cracked wide open, and that plug was the worst, or what about your valve seals for #5, a friend of mine suggested that to me

 

Definitely do the leak-down test. #5 is running rich so run the gambit...
Weak valve spring, burnt valve, maybe bad top piston ring.

If you suspect the injector, switch it with another...