Toyota Repair: car over heating, toyota camry, reservoir tank

Question
QUESTION: hi...i have a 1994 toyota camry 3.0 and its over heating only when the car its a stop or a red light, but a soon a take off the temperature drops, it happens only when the a/c its on... i replaced the radiator and the fan but problem persist....help enyone please...thanks

ANSWER: Has the thermostat been replaced? If not that would be my next step. Does the cooling fan turn on?

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QUESTION: yes the fun its working....i was trying to pressurise the radiator but its not holding pressure, the pressure releases at the reservoir tank.

Answer
You need to consider a possible blown headgasket, it can be checked using a kit from an autoparts store if you want to do it yourself, it's called a blocktest kit, just follow instructions or you can have a repair shop do this. When pressurizing is there an external leak? If not check the headgasket.