i have a 1990 s13 coupe with a notchtop s14 sr full swap done. relevant mods include fmic, upgraded rad, hks non recirc bov, full exhaust. bought the car already swapped and the idle has been rough since day one of ownership. now it has seemingly developed a throttle response issue that comes and goes at random.
the idle will jump around between 600 and 1k rpm, never dies though. always maintains idle, but its just rough. the car only had issue maintaining idle once after i started it after stalling it on a hill.
for the throttle issue, i can be cruising along normally and when i give throttle, theres no response for about a second or two. doesnt happen at all times, but will occasionally pop up. happened on one drive frequently but has only happened a handful of times since then.
the car runs rich but not excessively. pulls strong and has no issues under boost or while drifting/driving hard. on stock boost of 7psi.
the previous owner didnt build the car either, but thankfully he knows the person who did so im still learning about the car from who originally did the swap. the previous owner pointed to the tps as a potential cause of the idle issue.
before i dive into anything, any second opinions or other ideas would be greatly appreciated.
