B16, B18, B20
By jj_summers87
#323938 this is my first swap in a civic and I swaped in a jdm b18c in my hatch which has 60xxx mi on it and ran strong in the teg i pulled it out of. when i did the swap i put on a aftermarket godspeed intake manifold and the idle has started jumping around from 1000 rpm to 2000 rpm. I took off the IACV and the FITV thinking that they might be dirty and cleaned a lot of build up out of them bolted everything back up replaced the coolant and ran it to get any air pockets out and it did the same thing again. i also checked for a vacuume leak and none are to be found. no cel's are shown but i am getting tired of the irratic idle. i also heard that the tps could be bad but there is no cel. please help
By onibakagaijin
#323943 Your throttle position sensor could have gone bad and unfortunately their meant to stay on the throttle body so if you have an extra throttle body swap 'em and see. You can change just the sensor but tis a pain.
By jj_summers87
#323950 wouldn't the tps throw a cel if it was bad? i dont have an extra one to just throw at it but im shure i can find one.
By onibakagaijin
#324126 not always but it has been known to be linked with an erratic tach..ie looks like the rpms are jumping resulting in a bounching needle
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By Apexracing
#324142
jj_summers87 wrote:this is my first swap in a civic and I swaped in a jdm b18c in my hatch which has 60xxx mi on it and ran strong in the teg i pulled it out of. when i did the swap i put on a aftermarket godspeed intake manifold and the idle has started jumping around from 1000 rpm to 2000 rpm. I took off the IACV and the FITV thinking that they might be dirty and cleaned a lot of build up out of them bolted everything back up replaced the coolant and ran it to get any air pockets out and it did the same thing again. i also checked for a vacuume leak and none are to be found. no cel's are shown but i am getting tired of the irratic idle. i also heard that the tps could be bad but there is no cel. please help


Bad throttle body gasket or bad intake manifold gasket. Squirt water all around the gaskets. If the idle returns to normal for a few seconds then thats your issue.
By jj_summers87
#324901 ok.... i have replaced both throttle body gasket and intake manifold gasket just in case. i put on a new tps and i am still having this problem please someone help. also now i am throwing a knock sensor code and its BRAND NEW. please help i dont know where to go from here.
By jj_summers87
#325020 well i dont know if this is true or not but i was told that i need to flash my ecu because my sensors are reading more air in due to the new intake and more air out due to the exhaust. if this is true where can i find the things that i need like the program and the ODB1 to computer cables. thanks