ok guys... im running 1300cc secondaries which have been bored out from my stock 850's (by rc engineering through rx7store) and an apexi pfc. recently my car has begun to stumble severely under boost at about 3500rpm and when it does all i see is thick black smoke coming out the exhaust. i believe that im choking the engine with too much fuel

i believe that my 1300's have crapped out on me and are just pouring fuel in. does anyone know if this has happened to anyone before and what the failure rate is on these bored out injectors is?

i havent made any changes to the pfc and am running the base maps. been fine before the 1300's and started acting up a month after getting them installed

any advice would be greatly appreciated, thanks

 

ok ive got an update... it doesnt seem like its the injectors now... while driving and monitoring the pfc i noticed the inj duty is fine but the O2 reading is off the scale at 0.99-1.01v

what malfunctioning sensor could be sending false readings to the ecu and causing it to run so rich... keep in mind that this O2 reading is constant from idling to 3500rpm where the car stumbles and bogs. thanks again

im guessin it might be a bad O2 sensor or MAP sensor

 

you can check the oxygen sensor, but what mods are you running that would warrant 1300cc injectors? i ask because it sounds painfully obvious that you're not moving enough air to combust the amount of fuel you're putting in there ... so i need a better picture of what you're working with ...