the cel bulb is functional comes on when key is turned to on but then it goes off. its a dohc zc with a p28 ecu in a 93 civic. anyways theres no cel and the car runs great when its cold but sometimes runs like crap once it warms up. there is a slight crack in the radiator but it only barely seeps water water. havent had to fill the overflow in 3 months its so minor.

my concern is whether or not its the crack in the radiator messing with the fitv if its the o2 sensor or if it is the ect. note: the radiator fan would never come on so i had to rewire the fan to a switch which leads me to think that its the ect. just wanna double check my theories with some professionals before i go poking around in the engine bay with a multimeter

 

need more info. How is it running like "crap". need all details about how its running. does the car over heat, ect.

 

car does not overheat. as it decends down the rpm in gear it sounds like a slight backfiring is going on in the exhaust but i assume that to be due to a lack of backpressure since there is no cat and a hole in the exhaust.

the car runs very rich and i can feel the gain and lack of power alternating as i am climbing rpm in gear. the car has a hunting idle usually about 1k to 1.3k rpm sometimes its more vast sometimes it will stay steady at 1k. i have cleaned the iacv(eacv) but i have not toyed with the fitv as i am a broke college kid and need to be efficient with repairs need be made because my funds are limited

it is certain that it is engine temperature related. always runs awesome when its cold. once it warms up sometimes it runs like this sometimes it doesn't but more often it runs like crap than it does right

 

do you have an egr valve?

 

oooo i didn't think of that. there is alot of carbon buildup on the end of the exhaust and it repsonds well to fuel system cleaner but ive had a bad egr valve before on a ford ranger and this is much much more drastic. it almost seems like the car is missing its that bad but i know its not the dizzy and it has 2 months old plugs and wires. now my friend that i bought it from was running it on 87 and it runs better on 93 (which i dont know if the engine requires it but since its a jdm engine i assume it needs premium to prevent knock)