you got no worries with those numbers man . cylinder 2 is a little low but nothing to frett over

 

The leak down test will find a burned valve, if that were the problem. Is the car stock?

 

those #s are low, pour a little oil in the spark plug holes and redo the test. (warm) if the numbers are better than its the rings. if not do a leakdown test. if its the rings with such low miles my guess would be the first owner didnt break it in right, just started beating on it right away. those numbers arent low enough to make it missfire but low enough to decrease performance. i am surprised it ran good with that broken plug though.

 

I know, I meant I was surprised it didnt miss fire with the spark plug like it was. Yeah im going to probably do a wet compression test and see what happens but I guess the next thing to is do a cyl leak down test.

 

No the car has mods but it has always been tuned for. Not like a threw on a boost controller turned up the boost and called it a day.
My performance mods are:
3" TBE
Hallman MBC at 23psi
Muse LICP
K&N cone with Vibrant MAF adapter
Tuned for mods listed

 

As long as they are all with in about 10PSI of each other from the highest to the lowest then it all good man Yours are fine

 

that sounds normal to me, im a honda guy and from what i know about compression testing is its based on your compression ratio. a 10.2:1 compression b16 numbers the service limit is 180-220 across all four cylinders is an acceptable range. with an 8.8:1 4g63( if im not mistaken) that number should be lower. so your 140's may very well be within spec.

 

I had 170 + or - 2 psi in all my cylinders after last years beating on my engine. And Buschur uses stock compression on his 2.0L's.

That was on my brand new Snap-on gauge and a warm engine.

 

This is what a burned valve would look like.

 

Evo IX compression should be 145 psi with no more than 14psi difference between cylinders per Mitsubishi specs. The low limit is a ridiculous 92 psi per specs.

VIII's I think are around 175.

Plug damage is never a good thing. You might want to log that tune once you get new plugs. Also you could go to a step colder plug - The Denso IKH24 is a reasonably priced 1 step colder plug.

 

Thanks for the specs yeah I was surprised because I noticed nothing out of the ordinary in any of my logs during tuning. The only thing was when I first put the boost controller on I needed to get a base log to send out and it had 15* of knock but that was only for like 1 or 2 pulls of the logs. Then I didn't boost till I got the next map which pretty much took it all away. Im no expert but I dont think the 1 to 2 pulls with that knock would do that kind of damage. Im thinking it was some sort of pre ignition or detonation, even though the car hasn't been tuned for long and I would think it would take some use and abuse w/ detonation or some kind of unusual condition to break a plug. Im going to post pics of the plug just the hell of it anyways. Thanks for everyones input btw.

 

Did you check / replace the plugs before the tune? The plug damage could be from before the car was tuned. Since it's a used car you never know, someone could have run it for 5K miles with high boost and no tune for example. A precautionary Leak down test would probably be a good idea as well.

 

No I didnt change the plugs. I figured since they only had about 7k on them they should be fine. I bought the car bone stock but I was pretty sure it wasn't modded because everything was factory tight and in its place (i.e. no hoses out of place, different vac lines, T connectors etc.). I think im still gonna do a leak down test just to be sure but it should be fine.

 

Cyl head temps can get the plug glowing if high enough and plug is warm enough. On compression stroke with air/fuel charge, this is exactly what you don't want - the hot plug acts like a spark some 50 degrees BTDC under WOT. This is preignition, can be bad enough to send parts through the block or hood. Sometimes damage is just a spark electrode vaporized and redeposited on the surfaces of the exhaust mainifold. If this is the case perhaps #2 is being starved fuel running dangerous WOT afrs (mid 14's are the worse). Of course a WB can't detect this being a single sensor turbo car.

 

Thanks for the explanation so kinda regardless if my engine is fine now by chance, something happened to get that spark plug to get it like that either way. And possibly just a matter of time before something major happens?