'93 Lx 2.3 Ltr Tach Weirdness

[decollect]

Howdy all,

Tach is reading wrong. Reads very slow. 750 rpm idle reads 650, 1500 rpm reads about 1000, 2k reads 1300 etc. Seems the amount of deviation from actual rpm increases as actual rpm increases.
Where's the pickup for the tach go into? It's the 2.3 Ltr with dual spark distributorless ignition. Haynes book that I have doesn't show this problem.
Car is 5 spd, A/C (not sure if that matters) 84k showing on Odo, but possibly 184k gentle miles as well. Oh, and Oil gauge doesn't read right also. Reads a constant 35 or so psi at idle and at high rpm. Motor sounds tight, smooth and steady so I'm not worried too much about oil pressure. it's got a low Op light on it as well, I think. Daughter's car. (sigh)

Thanks.