Douglas Fraser, president of the United Automobile Workers, said today he is not having much luck selling Japanese automakers on the idea of building plants in the United States.

After two days of talks here, the American union leader said his hopes of moving this country's big companies toward a decision on building plants are not being fulfilled.

Nissan Motor Co., the No. 2 auto giant, talked only about possibly building trucks in the United States and then offered several reasons against building company passenger cars there, Fraser said.

"We had an unsatisfactory meeting with Nissan, and we told them so when we left," the UAW president declared in a speech before foreign correspondents. He said he does not expect the biggest, Toyota, to come up with a time-frame for opening a U.S. plant, either.

In response, he said he is warning of a congressional move within six or eight weeks to impose restraints on Japanese car exports to the United States.

At Nissan, he added, "They told us they did not want to cause -- and this is their word -- a disturbance in the American market. And when I look at what happened in 1979 where Toyota sales increased by 15 percent, (Nissan's) Datsuns by 39 percent and Mitsubishi by 33 percent and there 200,000 people unemployed I wonder what a disturbance is if that's not a disturbance."

Nissan executives told Fraser its higher 1979 sales arose from a big blacklog that built up when Americans swung back to buying large American-made cars before the latest oil crisis. Japanese cars are smaller and use less fuel. Fraser said such a swing in the market will never occur again because the United States has made an irreversible shift to smaller cars that save fuel.

The union leader, who meets Thurday with Toyota executives, also challenged the belief of Japanese automakers that American-made cars would not match the quality of those made in Japan.

Fraser quoted the president of Volkswagen-America as telling him that the quality of its cars made in Pennsylvania is higher than ones made in Germany. And Fraser said Honda has informed him that the quality of motorcycles made in its Ohio plant is better than those made in Japan.

Fraser warned that Rep. Charles Vanik (D-Ohio), chairman of a House Commitee on trade, has promised to hold hearings within a month on the soaring Japanese car imports and their effect on U.S. employment.

Both Nissan and Toyota are known to be skeptical of the plan to build U.S. plants but they are under pressure to do so because of fears Congress may impose protectionist measures this year.

Even the powerful Ministry of International Trade and Industry has begun trying to change their minds. According to industry sources MITI last weekend began reminding auto executives that there are political considerations involved and that Japanese industry should try to help reduce trade frictions between the two countries.

The government is known to believe that protectionist moves will grow quickly in an American election year and that the result may be a drastic roll-back in the quantity of car exports.

With Japanese models leading the way, foreign imports captured 22 percent of the American market last year and the movement toward legal restrictions has picked up steam.