A spate of new consumer complaints about stalling and faulty acceleration has prompted the National Highway Traffic Safety Administration to reopen an investigation into the design and performance of engines found in an estimated 2.7 million Chrysler cars and trucks manufactured for model years 1978-84.

But NHTSA officials emphasized yesterday that the investigation is a preliminary probe that could end without finding defects. An earlier NHTSA inquiry into the same complaints was called off last June because the agency could find no defect, an agency spokesman said.

The vehicles targeted by the resumed investigation include Chrysler Omni-Horizons, Aries-Reliant K cars, the mid-size LeBarron-400s, E-Class-600s and Dodge Rampage trucks.

A Chrysler spokesman said yesterday that NHTSA has not notified the company about a renewed investigation. But he said the company "would cooperate fully with NHTSA" and that Chrysler "is confident that any investigation will show that there are no defects."

Chrysler last year had "the best" auto safety recall record of all auto makers doing business in the United States, the company spokesman said. Of the nearly 6 million cars recalled last year, Chrysler brought back 7,500 for safety repairs.

Imports accounted for 3 million of the cars recalled last year, and General Motors Corp. and Ford Motor Co. together accounted for 2.9 million recalls in 1983.