ok i have a d15b2 with mpfi swap, wiring is good, I got no codes on the ecu, timing seems to be good, the car runs fine but then loses power like at 4500rpm then it stops at 5k, does anyone have any idea of what could it be? then when the car is fully warmed it misfires, specially like during the day when its hot, but at night when its a bit more cold it doesnt misfire, why is that?

 

Do you still have a catalytic converter on the car?

 

^no sir, no catalytic on the car

 

how is the fuel filter? i used to have a civic that had the same problem

 

well its a new fuel filter, so in yours it was the fuel filter giving you problems?

 

if ur still having this issue... do u have a check engine light on?

 

check your spark,sounds like a bad coil.
check resistance of the coil should read anywhere around .6 i believe.

or possibly an ecu problem.

i am having the same issues and it cuts out and backfires LOUD from the exhaust if i bring it to 5krpms,even lower sometimes..

but mine is because i fucked up a wire to the coil and havent fixed it yet..been workin on it all day..