KA-T blowby/misfire question

[Garber]

can anyone give me some pointers on figuring this one out?

the 3rd cylinder was misfiring slightly. unplugging the injector harness makes the misfire worse but plugging it in it gets slightly better but its still there. if i unplug any of the other injector harnesses the car wont idle at all.

and there is lots of blowby that wasnt there before this problem, its smoking out of the valve cover... smells like exhaust...

i changed the plug wires which didnt help. i put a new spark plug gasket on (the lower one) because it was slightly ripped, but that didnt help.


another thing, not sure how this is related, but when doing a boost leak test, the air is excaping through my valve cover breather....

http://www.facebook.com/home.php#!/video/video.php?v=1660244593843 (http://www.facebook.com/home.php#%21/video/video.php?v=1660244593843)

[Pirate_Freder]

well it sounds like you blew a piston ring or two. do a compression test following the instructions at this link: How to do a compression test on your engine – NICO Club (http://www.nicoclub.com/archives/how-to-do-a-compression-test-on-your-engine.html)

[j20accord00]

id do a compression test as well..but i had a similar problem once when i was running sr injectors. it was a bad o ring. causing it to misfire and have blow by..i replaced the o ring and changed the oil because it was loaded with fuel. both problems went away

[orion::S14]

Broke ringland on one of your pistons. You need to compression test the motor.

When did this start?

What's your setup? Tuning?

- Brian

[theboy]

lol, everyone immediately jumped on the ring land band wagon. That could be the case. But also check valve guides & seals. Hell check the head while your at it. Ive seen those crack at 10 psi. No matter what though your going to have to pull the head because compression testing will prove all of the above. And to pull the head your pulling the motor out so have fun doing a rebuild. Hopefully this time youll build it or get it built correctly. Im in the same boat as you, only i blew the head gasket and it puked water everywhere.

[Pirate_Freder]

except if he adds oil to the low cylinder(s) and the compression goes up it indicates that it is a a ring. if not then yes it could very well be something in the head

[Garber]

i will do a comp test and see what turns up. it came on slowly... like it started to get worse and worse which leads me to beleive its not a ring... at least im hoping.



its a stock ka24de with a to4e @5psi using sr injectors and tuned conservatively and on the rich side by steve at romisburning

[Garber]

so i finally had time to do a compression test. the results were.... uh... dissapointing lol.


cyl 1 -110psi
cyl 2- 110psi
cyl 3 - 30psi
cyl 4-110psi

then i added a capful of oil to cyl 3... it went up to maybe 40psi
then i added a capful of oil to cyl 1... it went up to 120psi.

then i checked the oil cap and it looked like this:

http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs788.snc4/66843_1728517180615_1469010013_1817047_2826961_n.j pg

WTF?

BHG? or a blown ring in every cylinder???

the car starts right up, idles a little rough.
runs very rich while driving
spools very late and feels really slow, even in boost.

if i put my finger over the valve cover breather, it builds up pressure and "poofs" a little cloud of fog out when i let it off.

[Garber]

it just doesnt make sense that 3 cylinders were exactly 110psi. and how would all of the rings go bad at the same time? i wonder if my comp gauge wasnt reading right. or if the battery wasnt turning over fast enough.

and why would there be moisture in the oil if it wasnt the head gasket?

can anyone explain why my head builds pressure when i cover the breather hole on the valve cover? sounds like a bad pcv to me...

also, when i did a boost leak test when this first started, air was escaping through the valve cover breather when i pressurized the piping. not sure how that happens either.



i think im missing something here.:wtf:

[japslapsilvia]

do a leak down test. the compression test doesnt give you enough information.

the leak down will allow u to pinpoint the problem