I just bought a 94 honda passport, and took it to jiffy lube to have oil changed. I'm not sure if it was before or after but the oil pressure runs at nearly 0 at idle and about 35 while driving.. I then proceeded to do what I should have done and changed the oil myself, with some heavier oil (10w40). Since then the oil pressure is about 5 lbs more. One important note: the oil pressure is nearly perfect before the vehicle warms up. Then once the normal temperature is reached, the oil pressure drops. (which is why I started by using a heavier oil.)
Low oil pressure on 1994 Honda Passport
by foosless in Wichita, KS on April 24, 2010
ANSWER by jason94 , April 24, 2010
The oil grade is important your right. Maybe your oil gauge is not working properly or possible oil pump, clogged filter or strainer, or regulator valve problems.