Have you checked and washed the selenoids (solenoid valves) that control KZFR? Do they open fully, clean filters? What type do you have - old or newer ones, after modification? With older ones - the filters are removed because they block the oil flow. In addition, to check the condition of the wires and the pins of the plug.
The oil is to be only as specified by the manufacturer (5W30) - a different oil may cause problems in the oil flow through the narrow channels of selenoid and KZFR (through the deposition of carbon deposits in them). In addition, change the oil more often (every 10-12 tkm) - there will be no problem with the timing and KZFR.
According to TIS2000 - after repair, the current adaptive parameters of the programming menu must be reset (F5 key of the control unit, fault group 13).