88 Camry: what is this code& timing issues?

I had the Camry manual downloaded from some university site, had all
the codes....but the hard drive this info was on died. The book mark
for the site with the free manuals was lost, too. It is an 88 Camry
wagon with 3SFE engine, 2 wheel drive.

I need to check the basic timing prior to replacing the camshaft
oil seal, so I can be sure I have the timing back just like it was.
I jumped T and E1 on diagnostic connector once the engine was up to
temp, per the Haynes Manual.There are two square blocks of small
connections. In the LH block of connections--- as you look at it
standing by the LH front fender--- this is the center one and the
upper right.
I think this is incorrect as this just caused the codes to be read
out...and it has one set now, code 51. I need to know what this is.
This did not cause any shift at all to the timing. As it is with
jumper in or out, the timing mark is about 3/8 in aft of the timing
index. The most aft mark is 20, so it is about 25 degrees....advanced
I think in that direction. THis can't be, how could it even run so
out of time?
I had about 80 lbs in the back and four adults in the car the
other day, and boy it sure was sluggish going up a freeway overpass...
had to nearly floor the gas pedal....but maybe this is all you can
get out of this little four-banger.

Thanks, Geronimo