i replaced my engine that had 155,000 miles with a newer used one with about 30,000 miles. since the swap my gas mileage is down by one third or more. everything else seems fine except that my cold start idle is up to 2000rpm’s until it drops to normal within 3 minutes.
thanks.
The toyota has an air idle control screw on the throttle body. Find it…it is usually under a black rubber plug and is a flathead screw…rather large in diameter. Screw out idle goes up…screw in idle goes down…this screw works in conjunction with air idle control valve so dont go wild with it… it is best to only use this screw when the engine is fully warmed up.
Might want to check the coolant or air temp sensors. Usually a cheap replacement and easy for a car owner. The car may stay too long in warm up or rich mode. Do not play with the factory air set screw. That is a air flow tested setting. You cannot and most outside of a factory cannot recalibrate this setting. You have bad input to the computer so look to the sensors.