Hi Gents,
Trying to figure this one out... My 2012 XFR melted the cylinder 8 stock spark plug (center electrode destroyed) for the 2nd time in a year. Before it went "pop" the cylinder was throughing a misfire code. I added some BG44K and then it went into "reduced performance." Anyone else have this issue? Thinking perhaps a clogged injector, carbon buildup? Only mods upper pulley, y-pipe intake, tune for pulley.

 

Never had that issue with mine, coming up on my 100K service. Changed my plugs at 44kmi.

 

Sure sounds like you are running a bit lean in that hole. Have you "bore-scoped" down inside when the plug is out? Does the piston face look good?

That sounds scary.

 

You could try swapping the injector with another cylinder and see if the problem moves with it.

But, I would probably just replace it with a new one so I didn't have to mess around since that's the most likely culprit.

 

Check STFTs and LTFTs for lean situation.

If the spark plug electrode 'melted', the piston may also be damaged.

 

The piston face doesn't look great but not bad.

 

Well,... I drove around and some nice cold Cali air last night and punched it a couple times...on the third time....limp mode again! Just like before, cylinder 8 misfire and probably melted the plug. Well going to change injector this time.

 

Are they the right plugs? No-one else ever seems to have this melting!

 

Yes, they are correct plugs. Anyone had any issuses with clogged injectors? Would a clogged injector throw a code?

 

To melt it must be far too hot, so lean - because fuel cools things down. Which is why at WOT runs rich.

 

Logical thought would be a clogged injector not providing the fuel at WOT?

 

It's sounds like one of the possibilities, along with all the others listed for the misfire code (& any others) you had.

 

I would agree on a clogged injector or injector at end of life.
If you are using an independent shop you can get the injector a lot cheaper off of ebay. Your shop would also need to buy the injector installation tool.
I would actually do what the forum members advised and have the injector swapper to a different cylinder and see if the problem follows, if it does you know it is the injector, if not and the issue stays on number 8, then it might be a fuel delivery issue, or electrical supply to the injector.

 

So I had my Indy replace the spark plug. It was collapsed again. Unfortunately they didn't have the injector puller and I didn't want them to perform the change without one. The car runs fine with the new plug. I think two things might have an impact on the plugs melting - 1.) It always happens after I hit the rev limiter once or twice in succession after driving hard. 2.) BG44k cleaner is in the gas when they melt.

Could this combination increase the cylinder heat so much that it melts #8?

 

I've ran BG44 in my XFR with no issues. Your leaning out in that cylinder, you really don't want to burn a valve in the AJ133SC, get it fixed,

 

#8 is the furthest from the pumps and most likely to run lean if low on fuel pressure from the hi pressure pumps. But I would definitely just change the injector. Theyre cheap now. I have injectors for OEM for $100 ea shipped It is definitely lean if melting electrode