1990 toyota corolla high idle when is in parking but not in drive shift

SOURCE: Car/1990 Toyota Corolla

If Biggy1 has described it right, I think when you remove the WIRE to the spark plug ( not the plug itself ) and oil jumps out, there is a cylindrical seal that needs replacing and one does not need to even remove the cylinder head.
I have the same problem with my corolla. On the other hand if Biggy meant when removing the SPARK PLUG oil was on the contacts....

SOURCE: 2004 toyota corolla idle jumps

If you dont have any trouble codes, this usually occurs when the idle air control valve (IAC) is going bad.

SOURCE: 1996 Toyota Corolla--Shift stuck in park

TRY THIS LINK

SOURCE: Unable to shift from park into drive

there is a solenoid that releases the shifter when you step on the brake pedal.there is by the shifter a little tab that can be popped out with a small screwdriver,and using your key,put into the hole and the mechanical device will release the shifter.
it is called a shift lock override

SOURCE: Toyota 1999 Corolla,low idle,my corolla idles at

adjust the accelerator cable.

Testimonial: "i thought the idle was ecu controlled,but i see what your saying,ajust cable stop.ie allen screw with locknut to bring up revs.thanks"