Hi thanks for your time and trying to help, I have a almost stock evo VIII.
The service engine soon light came on and it was lagging really bad at low rpms. It would seem like it was going to stall but then it would just kick in and take off and it could rev all the way to red line no problem. I changed the spark plugs and and then the low rpm lag went away, but when I get to around 4500 or 5000 RPMS (around 15 psi of boost) the car jumps like crazy and blows big black smoke, and accelerates slow. It keeps jumping until I left off the gas, it seems to not jump so bad if I dont have the throtle in all the way. My air/fuel gauge is showing the car is running rich when it jumps and the gauge doesnt move. But the entire "rich" side lights up instead of just one light, there are all 5 or so of them lit up. The service engine light has not turned on since I changed the plugs.
I'm going to look for a loose vacume line or something, but I don't have licence for 30 more days so I can't drive it to a shop. Please help me I feel like a n00b.
Thanks,
Nick

 

i think your turbo is done

 

+1

 

my car did somthing similar when i didnt get the mass air flow plug in the whole way, check that out

 

Did you gap the plugs correctly?

 

I'd say check your mass air meter and oryour front o2 sensor. If your CEL light came on then its related to a sensor, just plug in a obd2 reader ( any auto parts store for around 65 bucks) get the code and look up whats wrong with your car. From what your saying it does not sound like the turbo, due to the fact a blown turbo does not make your car run rich however the two sensors I listed can. Good Luck and hope this helps. Imprezv

 

Thanks guys I will go look at the MAF and probably go get a one of those readers.
I also forgot to say when the car is in nuetral or u have the clutch in... it can rev up really fast just fine, and it look looks like at 15psi the jumping shaking accures no matter where the rpms are. Thanks again.

 

Do those readers read past codes.. because the light isn't on anymore...

 

Well I don't remember what I gapped them at, but i gapped them at whatever the ones i pulled out were gapped at, could this be a problem?

 

Im having the same problem with my IX

 

How Many miles on the car? Are you on the stock clutch?So is the car bucking (jumping)?
Put some new plugs in and gap to .024. Also which plugs did you put in it?

Did you check the snorkle on the intake (if you have the stock intake)to make sure it is not sucking up to the hood.

Did you do a boost leak test?

 

car has about 32000 miles. It has an ACT HDSS clutch with about 2000 miles on it. And intake is not stock.. Yes the car is bucking, but it will still accelerate, but bucks around. I will go buy some plugs later today and gap then to .024 and see what happens.. and i'm not sure how to do a boost leak test.. my boost gauges doesn't show anything crazy.. thanks

 

here:https://www.evolutionm.net/forums/sh...ight=leak+test

 

check if anythings loose (maf plug, lines, maybe exhaust manifold)

 

i dont mean to steal your thread, but im having the same exact problem with my car. 30000 miles, stock clutch, stock intake, so is everything else :/