A week of street violence linked to price increases has raised questions about the ability of Guatemala's military rulers to run the country effectively at a time of acute economic crisis.

The demonstration of economic discontent underlined the need to return the country to civilian rule in elections scheduled for Nov. 3, according to Guatemalan politicians and diplomatic observers. But they also have stirred fears -- never far from the surface in Guatemala -- that rightist military officers could force cancellation of the vote in the name of public order if the disorders continue.

Guatemalan political sources and diplomats stationed here said this was the main reason none of the leading presidential candidates had assumed a major role in dealing with rioting and demonstrations or the issues they raised. The protests were touched off originally by an attempt to raise bus fares from about 3 cents to 5, but were seen as a symptom of widespread discontent with the economic situation.

There also has been a new wave of political kidnapings and killings, the most recent being the kidnaping Thursday of Christian Democratic union leader Julio Celso de Leon.

"I was very disappointed in these political parties," said a European diplomat. "They did nothing, and then the Army stepped in, and that was it."

The prudence may have been well-founded, according to Guatemalan political sources. Some officers, backed by right-wing political sympathizers, raised the idea of pushing aside the chief of state, Gen. Oscar Humberto Mejia Victores, and replacing him with another officer more inclined to postpone the elections, they said.

Mejia led a coup that overthrew Gen. Efrain Rios Montt in August 1983. He consistently has pledged to shepherd the country to elections and civilian rule. Despite the street disorders, he renewed that pledge in a statement last week.

U.S. Ambassador Alberto Piedra also reiterated to Guatemalan officials the Reagan administration's insistence that the elections be held on schedule, diplomatic sources reported. The administration's message also was conveyed to the Guatemalan Embassy in Washington, Guatemalan officials said.

The U.S. House of Representatives has made return to civilian rule a condition for disbursement of badly needed U.S. aid, including an administration attempt to renew military aid cut off in 1977 because of human rights abuses.

Guatemalan political sources, speaking anonymously, said the option most actively discussed within the officer corps during the crisis was Mejia's replacement by a civilian-military junta committed to carrying out the election schedule but also to improving management of the economy. Although it is still possible, this course apparently has been discarded because it would give the appearance of increased instability only two months from the elections, these sources said.

The popular unrest died down over the weekend after what authorities announced were more than 1,000 arrests and thousands of dollars in damage to cars, buses and downtown shops. Several persons were reported killed, but the number was not announced.

The return to calm removed the atmosphere of crisis for the time being. But it left Mejia's military government with Guatemala's worst economic situation in years and few prospects of improvement in the near future.

Mejia's handling of the unrest was widely viewed as undermining his leadership. When opposition to the bus fare increases first arose, he publicly vowed that they never would be rescinded. Then last Wednesday, after mob violence broke out, he announced that the fare raises would be canceled after all, promising as well a freeze on prices of basic necessities and a salary increase for public employes.

The vacillation, uncharacteristic in the Guatemalan military, marked the second time this year that Mejia has made an about-face in economic policy. Strong opposition from business leaders forced him to rescind a tax package last April, when reports of a possible coup by other officers also began to circulate.

In addition, the Guatemalan Army occupied the country's oldest and largest university last week, defying a long tradition granting the state-supported institution autonomy. The rector, Eduardo Meyer Maldonado, described the decision to enter the university compound as "irrational" and "a historic error."

Military officers said the Army intervened because leftist "subversives" within the university were seeking to incite more antigovernment violence and arm the protesters. At a news conference organized by the Army, officers displayed rifles and leftist literature they said were found on the campus.

In an interview, Meyer said that the street disturbances were caused by "lack of competence" in the military government and that the university had nothing to do with them. The weapons displayed by the Army were brought to the campus by soldiers for the news conference, he said.

"It was a silly, grotesque show," he added. "Nobody believes them."

Jorge Carpio Nicolle, a presidential candidate from the centrist Union of the National Center, also described the university takeover as "a tremendous mistake." Although troops were ordered out after only three days, he said the violation of Guatemalan tradition generated opposition from many Guatemalans who ordinarily support the Army.

Despite the strain, Carpio voiced confidence the military will turn over the government to elected civilians on schedule because of the country's economic problems along with pressure from the United States and other friendly countries.

"The problem is that Guatemala is under tremendous economic pressures, and the military rulers don't know what to do about it," he said.

Vinicio Cerezo, a Christian Democrat who is the other top-ranked presidential candidate, said Guatemala's business leaders have come to realize that political and economic reforms, including a civilian government that could open the way to more foreign aid, are necessary.

"If they don't do something about this problem, they are going to have a civil war" in addition to the guerrilla fighting already going on in parts of the country, he added.