normaly all "tuned" starlets do it. and normaly when you put an FPR on.. the ECU will try everything to put it to 14.7afr on idle.. could be its the ECU "fighting" the extra fuel ?
im not sure about this... but seen 2 perfectly stock starlets that where perfect.. one of them as soon as it was fitted with an fcd + rrfpr and a decat... started to play with idle.
my car doesnt have and fcd and fpr. whats installed in my car is safc, supra fuel pump,5efhe cams,nst underdrive crank pulley. msd blaster ss coil and 9mm wires. could be the pulley?