Democratic Presidential candidate Walter F. Mondale accused the Reagan administration today of failing to prepare a coordinated solution to the West's economic ills at the upcoming Williamsburg summit.

Mondale, speaking at a luncheon of the Los Angeles World Affairs Council, said the administration could make significant progress on easing world debt and trade barriers and ending currency misalignment that was costing U.S. jobs, but said there was "no evidence" the administration was "aiming for an effective conference."

The undervaluation of the Japanese yen, Mondale said, forced Caterpillar Tractor Co. to sell "the world's best bulldozer" for $33,000 more than a competing Japanese firm. "The administration thinks intervention in currency markets is wrong in principle," Mondale said. "I believe their policy is the triumph of ideology over common sense."

Mondale, a former vice president and candidate for the Democratic presidential nomination in 1984, also sharply attacked the administration for producing record federal deficits and further crippling U.S. trade. He said Martin Feldstein, chairman of the Council of Economic Advisers, recently said high interest rates created by deficits were good because they attracted foreign capital to the United States. A spokesman said Feldstein had noted the relationship of high interest rates and increased foreign investment, but did not describe it as "good."