I have an Evo8 with a full exhaust and exhaust manifold, injen intake and intercooler pipes, hks bov, and a manual boost controller pushing 24 pounds of boost with a decent tune done at a local shop. A couple days ago it threw a code for running rich. Before I could make it home it lost a lot of power when i hit third gear all of a sudden and would barely hold an idle at a stop. it then threw a code for multiple cylinder misfires and not the rich fuel anymore. I checked the plugs and they were all good but one which was completely melted. I changed all the plugs at a hefty price that ngks are and it ran a little bitter but then later threw the same mcm code. Would it be one of the coil packs and should i get it tuned again after all this? also could this have done any serious damage to the internals? I've avoided driving the car unless i absolutely have to, but this is my baby and it's upsetting... any help would be great thanks.

 

I'd suggest one cylinder was running lean and detonating. This would be caused by a fuel injector problem.

 

Where did you gap the plugs? If you can, i will try swap coils with other evo owner see if that helps.

 

A clogged fuel injector? And the plugs are gapped at .025. I don't know anyone else around here that has an evo, because i did consider swapping them out.

 

Well, lets go back to the engine too rich code. Here's what the possible causes are according to my factory service manual.

Volume air flow sensor failed
This wouldn't affect only one cylinder, so, unlikely

Injector failed

Incorrect fuel pressure
This wouldn't affect only one cylinder, so, unlikely

Engine coolant sensor failed
This wouldn't affect only one cylinder, so, unlikely

Intake air temperature sensor failed
This wouldn't affect only one cylinder, so, unlikely

Barometric sensor failed
This wouldn't affect only one cylinder, so, unlikely

Harness damage in injector circuit or connector damage

ECM failed


BTW, I think it is time to do a compression check.

 

wellll i did a compression test and a leak down test. i had close to no compression in the second cylinder and the leak down was 96%... so its time for a rebuild. :/

 

Sorry man. GL with the rebuild.

 

thanks, any recommendations for pistons and rods? I was thinking je pistons and manley turbo tuff rods. I'm going to replace the injectors and fuel pump while i'm at it.

 

I suggest you start a new thread, something entitled "Recommendations for New Build" or such like and you will get interest from plenty of people, people smarter than me.

 

there is a thread on here about "which rods should i use" the turbo tuffs are great rods but the map"howard" rods are very strong also. they are in my friends 800hp 2.3. just depends on tour power goals and the bigger picture. as for pistons weisco is about the best. je would be 2nd best. sorry about the engine failure but all the reason to justify the "BUILD"