NEMES1S

I have been battling a random misfire, thought it was the coil, got a used one that supposedly works, and it throws a code yet again for cylinder 11. I grab my buddy's scanner and it shows the conditions when the code was tripped, it's normally around 4850 rpm and 60mph but I noticed the map reading of 57 inhg.....that's about 28 psi, I know my speedriven tune add psi but isn't 28 way too much for this engine? I also changed my fuel filtering and the other plugs were done about 12k miles ago, but looking for any and all other ideas.

NEMES1S

And this is what one of the 11 spark plugs looks like....

Ekselent

I have the same tune and my max psi is around 21-22 psi.
I think 28 psi is to much...

NEMES1S

I was thinking it was 21-22 also. Are these stock turbos even capable of 28 psi at 4800 rpm? I'd think they are running out of flow well before that. I assume the map signal is supposed to be reading actual engine boost right?

Ekselent

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I think your "wastegate" don't work. It don't open at al.
The pipeline which do that work is cut of or has been interrupted or disconnected from a joint.
I think also that much of boost will explode the gas by itself.(before the spark plug). Its dangerous and there fore your spark plug look like that. (engine knocking)
I would not drive any, at least not with a big pressures before you fix the fault.

ItalianJoe1

The sensor reading is absolute, meaning it's including ambient as the first part. So subtract 14.7psi from that to get your boost reading. That sensor will register about 30 in/hg at 0 psi, manifold pressure same as outside pressure (i.e. with the engine off..) so you have to figure that into your calculations.

NEMES1S

Anyone have a misfire bad enough to cook their engine? That one plug looked pretty shot, and a friend said with that much oil on the plug it could be something serious. I can't explain where all the oil on the plugs is coming from. It looks like the valve cover gaskets are just fine.

F1BHP

If I was to guess it would be a situation with the engine is running rich due to incorrect air/fuel mixture. Hopefully Speedriven will be able to help you. Keep us posted.