I have a 95 4Runner with 93k miles. Can anyone advise me why the revs increase considerably when it is put into PARKING gear - is this normal?
Thankyou for reading this message.

No, this is not normal.

Actually, this is normal when the engine is quite cold and is still on fast idle. Might mean that your engine coolant temperature sensor is bad and telling the ECU that your engine is cold, even when it is not - putting your engine in fast idle.

Still thinking about it.

Thanks for your reply Brian - I am having trouble with the temperature gauge, i.e. it is not reading any temperature. It seems that the two problems may be related.

Might mean your engine is really cold. Check your thermostat. Might be stuck open (might not have one). Replace it if there's any question. Running cold is bad for an engine.