No, during the 70's and part of the early 80's they were terrible quality.
But what the Japanese makers did was they analyzed the failures and rolled the findings back into the manufacturing line so that they continuously improved the product. After quite some time at this, they took the "quality built" mantle for themselves.
My father, mid to late 70's, worked as an auto-mechanic for a local Datsun dealer (Datsun is the company we know today as Nissan). Datsun corporate wanted every failed part on every car repaired returned to them for analysis as to why it failed. The other Japanese brands all did the same.
I've often heard Toyota cited as the Japanese manufacturing exemplar, with their "kaizen" (constant improvement) approach.
From the Freebsd fortune file:
Mr. Jones related an incident from "some time back" when IBM Canada
Ltd. of Markham, Ont., ordered some parts from a new supplier in Japan.
The company noted in its order that acceptable quality allowed for 1.5
percent defects (a fairly high standard in North America at the time).
The Japanese sent the order, with a few parts packaged separately in
plastic. The accompanying letter said: "We don't know why you want 1.5
percent defective parts, but for your convenience, we've packed them
separately."
-- Excerpted from an article in The (Toronto) Globe and Mail
The thing I love about the Japanese automotive story is that their success was earned. It wasn't some story of regulatory capture or protectionism or blitzscaling, etc. They built an auto industry over generations and raised the quality line for everyone.