Just got My first evo few months ago and when i got it had a small miss /lag nothing bad just throught it was cause it was on empty light Low fuel anyway fueled up and was still there few days later still there, now the car was due For the road test and in sweden they do the CO2 test which it failed 4* over,
So i put new converter in exhast
Put a evo 8 turbo on near new
Install a catch tank
New spark pulgs bpr8es
Near new coils
And a new water pump that started to leak
Now i have a much bigger miss/ lag and a crappy idle, i unplug the maf and idle returns to normal but a short drive 100metres like this and im worst off so not sure whats happening. Iv got a evo 6 ecu to install but i was thinkn i should sort this first. Any help would be great thanks

 

Just been reading and the car had hks air filter already fitted when i got and that can cause a bad idle or slight lag/miss now that i put race cat and 3 inch from the turbo this could cause it to be worst so putting the 6 ECU and geting a tune is probably the fix i hope

 

Could start with cleaning the maf and throttle body. If that doesn't help then maybe replace the maf. Also do a compression test after just incase.

What did you gap the plugs at? And what kind of fuel are you using? Any fuel leaks?

 

Can you hook up a scan tool to see which cylinder(s) is misfiring?

 

OBDII wasnt in the JDM evo's until the Evo 6 Im pretty sure. He will need the E6 ecu and to use EVOSCAN with ecuflash and have all the MUTII crap

 

Thanks guys il c what i can get done today

 

I checked gap on plugs it was .7mm so throught that was good i saw they were white at the tip when i pulled them out must be getn super hot or maybe wrong plug il try the bpr7es today and gap to .6mm and try the cleaner For maf and c how that goes if not luck il get compression test done to c, i was thinkn maybe a head gasket but coolant and oil is algd and no sign of bubbles in coolant so could be just the maf il try to reset ECU Then let it idle For 30mins after new plugs wires and cleaned maf c what hapens

 

1.The IACV on IV's is commonly bad for it's age. Be sure to check that.
2.The IV's idle better on recirculating unless you tune for VTA.
3.Any simple boost or vacuum leak will mess up a IV.
4.Are you upgrading the injectors to go with ECU?
5.Can you put up a video of it running?
Good luck! IV's are a blast.

 

Hey thanks For that i check that 2, funny thing i order some parts coil wires new plugs maf cleaner and a themostat, i took maf off got some baby wipes in there gave it a good clean was real dirty,so i drove to Work in the evo less Then 5 km and just drove half throtle and it got upto 5000 rpm like that , 4 hrs later drove home and gave it a good boost to My surprise it went well no lag or miss but i have noticed a bit move lag with the evo 8 turbo and boost only got upto .7 bar which i was geting 1.2bar b4 Any know whats caused the lower boost of got a controller im going to stick in c what hapns, c if the car runs good today as it Did last nite i was so happy im boosting again.