Friends. Seeking for help with my 1993 SC400 / Soarer 4.0L, Automatic gearbox, equipped with first revision of 1uz-fe Car was standing for last 7 years, later we begun restoration process.
-- the issue
The car always running low rpm, below 650-700. Actually in idle (P or N) the car is about 500 rpm, when shifting into gear, the rpm drops to about 300-400, but the car still runs good, has power, throws tail, drifting no problem at all. When AC is on, rpm drops even lower. Sometimes reaching as much as 100-150rpm. ONLY with AC switched on, the car periodically shaking hard, similar to somebody kicking the car on the side. This shaking behaviour may happen once per few seconds, or few times a second, rapidly. Also this occurs only when the vehicle is warmed up, in closed loop... Strange thing
-- whats done...
Plugs Cables IAC valve cleaned and confirmed proper workability by giving voltage to s1-s4 and s4-s1 connectors, resistance confirmed as well. EGR valve cleaned and confirmed workability following factory manual. Throttle body is cleaned Throttle position sensor is replaced and calibrated by the book to align with all the parameters. Timing is done with water pump Water temp sensors replaced. Fan, ecu and gauge sensors. New PCV valve
-- whats not done
Hoses(arrived) Caps and rotors Coil packs(on their way)
--- error codes
21 - left (driver side) main oxygen sensor 25 - running lean I believe both codes related to clogged catalytic convertors which is going to be cut next week as well.
Any help, advice what to look at greatly appreciated.