I took the top of my IM off today (JDM H22a, OBDI) and there was what looked like a bunch of carbon buildup... it had pretty much a hard, dry, black coating all inside of it. I am still working out the bugs of my motor swap and I am having some mean misfiring problems (wiring I believe), which has also caouse me to get around 19mpg for this tank. Maybe this im stuff is related?

 

misfiring? Hmm, I don't know

Perhaps your intake valves aren't seating properly..

have you ruled out oil from the crankcase?

 

Well, I did a compression test 2 weeks ago.. 202 202 192 202

I changed my PCV valve a week ago... and I don't have an intake hooked up on my car... but that is because I'm not driving it yet... just trying to get it to run right in the garage first

Would the fact that I don't have the tube from an intake to my VC hooked up cause this?

 

how many miles are on the engine? have you ever used an induction cleaner? if not GM makes a good one, part # 1052626. we use that on all the hondas at work.


[Modified by whatVTEC, 4:04 AM 7/12/2002]

 

Time to look for an oil catchcan.

That carbon buildup is a result of oil blowby reculated through the IM via the PCV system.

 

Good idea... I've seen the endyn one.. but its pricy, and I've got an h-series motor. Any alternatives?

 

yeah, get over it. It doesnt hurt anything, if you dont like it, then clean it and dont run your PCV. Just keep in mind that almost EVERY engine has that, and its not the cause of your misfire.