I've change the oil pan gasket, engine cover gasket, the engine is still leaking. I've checked and the oil seems come from the distributor. So I gonna change the O-ring. I read the manual, it is very easy to take it off and install. My question is if I just change the o-ring, do I need to do some adjustment as the manual said?

SET NO. 1 CYLINDER TO TDC/COMPRESSION
Turn the crankshaft clockwise, and position the slit of
the intake camshaft as shown in the illustration.

Or just install it as it was. I am confused. Thanks in advance.

When I pulled my distributor out to change the ignition coil, I just made marks where everything was at and put it back on as/was. Didn't seem to affect anything. However....I think that was probably dumb luck. If you got the means, I'd tune it right if I were you.

If you have the rotor off and the dust cover off, you can see many places to check the orientation of the distributor. Digital camera is great for this if memory and artistry are lacking. If the motor doesn't move then you only need to make sure the distributor body is aligned the same way as you took it out. I just did my 92 and there was no problem. Lube the o ring as described in the manual. The old o-ring will likely break apart upon removal. Mine was completely brittle.

Thanks guys!

Btw go to website:

http://www.valvoline.com/maxlife/microsite.asp

You can get free 5 qts or 1 gallon valvoline maxlife engine oil (or synthetic) after rebate by July 15 2006.

See here http://www.toyotanation.com/forum/t83978.html

Just make sure you take your time and do not get pissed off if it doesn't go right in. Make sure to have plenty of vasoline on the o-ring, it will be a tight fit getting it back in.