The suburbs of Romania's capital are dark and eerily still these cool October nights as electricity is abruptly switched off. By day, residents can be seen unloading firewood into fuel storage bins meant to hold coal.

Even as the stately ranks of trees along Bucharest's broad boulevards glow with the colors of autumn, Romanians are grimly preparing for another dark winter of austerity. Severe energy shortages, heavy foreign debt payments and the worst grain harvest in at least 15 years are threatening this Communist-ruled Balkan nation with privation unknown in Eastern Europe since its recovery from World War II.

"It's been a very bad year for Romania, and things aren't getting any better," a western diplomat said. "They're living on the ragged edge here. The energy situation is going to be very bad. Malnutrition is going to be a real problem."

Romania's industry and its 22 million people are still reeling from an unusually cold winter that blocked production and fuel transportation and prompted the government of President Nicolae Ceausescu to put a ban on private autos and drastic limitations on citizens' use of lights, heating and household appliances.

The restrictions eased, and cars returned to the roads with the coming of spring. But since then a drought has contributed to a poor summer harvest that has left Romania with only half its target supply of wheat, barley and corn, according to western estimates, and the electrical power crisis has worsened.

[Two top officials with responsibility for energy -- Deputy Premier Ion Avram and Electrical Power Minister Nicolae Busui -- were fired Friday for "grave deficiencies," and troops were deployed to run power stations, the Manchester Guardian reported. It said the moves came after a Communist Party executive committee meeting presided over by Ceausescu.]

Romanian officials, while reticent about agriculture, say export earnings dropped 5 percent in the first eight months of this year compared with 1984 and that the growth of industrial output is 30 percent below expectations. Oil and coal production has slackened and hydroelectric plants have operated at low capacity because of water shortages in reservoirs, they say.

Moreover, officials insist that no grain will be imported this year, even though the estimated harvest of 14.7 million tons is well below normal consumption needs of 19 million, according to western experts. As a result, western experts predict -- and Romanian officials do not deny -- that more months of sacrifice lie ahead.

"The people will be asked to comply with the need to be reasonable and judicious about their consumption," said Radu Opincaru, a ministry official.

The hardships are already easily glimpsed in Bucharest, where dimmed street lights, long lines outside shops and street scenes of impoverishment stand in glaring contrast to the feverish work on two monumental construction projects -- a subway system and a mile-long complex of government buildings -- ordered by Ceausescu.

Residents, urged by authorities not to use more than one light bulb of 60 watts in each room of their homes, say electricity in some suburbs is regularly cut during the night beginning at 11 p.m. and during daytime working hours. Television broadcasting lasts only two hours a day.

Western embassies, urged by authorities to install costly oil-burning heat systems, have heard of scarce coal supplies being replaced with firewood in some areas and of residential blocks being disconnected from the hard-pressed central gas system.

Flour, sugar and cooking oil are rationed, and butter and meat other than sausage are usually unavailable. Travelers report that farmer's markets in towns of the northeastern interior are seriously undersupplied and residents are scrambling to arrange private food sources or access to diplomatic shops.

In Bucharest's large central market, carrots are finger-sized, potatoes are moldy and there are no tomatoes or other vegetables.

One recent evening, several men could be seen sleeping on grimy sidewalks, and one group had built a small wood fire on the pavement facing the construction site of the new government center, which even after midnight was brightly lit with floodlights.

While denying most reports of shortages and restrictions for private citizens, officials acknowledge some emergency measures for industry. These include a new program under which managers and ministry functionaries will suffer salary cuts of up to 50 percent if production quotas are not met in export-related industries. Managers deemed responsible for exceeding quotas can receive bonuses of up to 20 percent.

Electrical Ministry official Gheorghe Plavitu said utility rates are increased for families using more than 1,000 kilowatt-hours a year -- roughly equal to two 60-watt bulbs left burning.

Government spokesmen blame the economic troubles on bad weather, poor international trends and declining prices for Romanian exports such as food and construction projects. Official figures suggest that despite the setbacks, Romania's economy is expanding at a booming pace unmatched in the rest of Europe.

Western experts, however, dismiss the official statistics and blame years of bad government policies and mismanagement for the worsening crisis. Romania borrowed heavily in the 1970s for huge expansions of industries such as steel and petrochemicals that now operate at a fraction of their capacity because of shortages of fuel and raw materials. Since 1981, critics say, the government has compounded its problems with a crash program to pay off its western debts through severe austerity.

Stelian Marin, a Finance Ministry director, confirmed in an interview that Romania is pressing ahead with debt payments despite its internal problems. The foreign debt is now $6.4 billion, he said, compared with $7.1 billion at the end of 1984 and $10 billion four years ago. Net debt to the West should be eliminated by 1987, he said.

The increasing hardships of this policy seem to have no effect on Ceausescu's 20-year-old monopoly on power in the government and party, or on the ability of security forces to erase all traces of public dissent with minimal overt repression.

Diplomats watching for change in Romania have been reduced to speculating over the health of the 67-year-old strongman, rumored to be afflicted with problems including cancer. Although such reports are taken seriously by diplomats here, a variety of observers who have seen Ceausescu recently said he appears healthy and active.