Federal Immigration and Naturalization Service officials are delaying the start of deportation proceedings against 172 Iranian men jailed here while lawyers and prison officials try to persuade the young prisoners to end their eight-day-old hunger strike.

Already, 18 of the Iranians brought here to the Federal Correctional Institute at Otisville early Saturday morning from Washington, D.C., have been briefly hospitalized at the prison medical center for undernourishment and fed a liquid nutrition substitute.

One of the prisoners, who had refused the liquid, was forced to take it when prison officials determined that his health was in jeopardy. He was held down by prison authorities and a food intake tube was pushed down his throat, prison officials said.

Three other Iranians, who were taken to a private hospital about 25 miles away for dehydration associated with the hunger strike, are listed in stable condition. They are being kept there under guard, and hospital authorities refuse to comment on the case.

The Iranians met outside their cells for several hours today with visitors who included two representatives of the Iranian Student Association; the Rev. John Adams, a United Methodist clergyman, and Dr. Ahmad Falah, an Iranian physician from New York.

J. Michael Quinlan, the prison warden, said the students also spent much of the day sitting on the floor outside their cells listening to one of their number who acted as a spokesman.

The generally closed-mouthed position taken by officials at this prison high in the Catskill Mountains partly reflects the political sensitivity associated with the case, which could affect efforts to free the 52 American hostages in Iran. All of the Iranian prisoners face deportation because they have refused to give their names.

Immigration Sevice officials on the scene refused even to see reporters, who were kept isolated in a separate ; building a few yards from the main facility.

When an attorney, Paul O'Dwyer, who came to inquire about the Iranians, began an impromtptu press conference today, two prison officials asked him to leave the prison grounds.

Except for those who visited them today, few if any persons other than prison officials, immigration officers and about a half-dozen lawyers have been allowed to see the Iranians since they were unloaded from five chartered buses Saturday morning and placed in the 84-square-foot cells.

Prison officials have set as their fisrt priority to get the Iranians to eat, according to Suzanne Knight, the prison spokesperson. But so far they have had little success, she said.

At least twice a day, food trays are put into their cells, but most of it remains untouched. According to Knight, the Iranians will say only that they are on a fast and that "we will not eat."

She estimated that, aside from those hospitalized, fewer than a dozen have eaten anything more than small sugar packets and water. Some drink the fruit juices that are served with the meals, and fewer than 10, she estimated, have eaten any solid food.

They spend most of the day in their cells, lying on the beds, often praying and holding conversation in their native Persian, with their fellow Iranians jailed in the same unit, Knight said.

They have only one window at the back of the cell looking out onto the still-unfinished prison grounds and a small narrow window, with glass, in the metal door leading into their cells.

Knight described them as "pleasant, cooperative," but also having a little apprehension about what's going on."

Aside from today's group meetings, the Iranians have been locked in their cells, allowed out only to shower, to make collect long distance telephone calls and to meet with lawyers, prison officials or doctors.

This prison, which was not scheduled to open until October, has no recreation facility yet, so there is nothing for the Iranians to do except read magazines.

They were transported here from the Washington, D.C., jail since this prison is the only federal facility with enough available space. D.C. police requested they be moved from The D.C. jail after disorderly charges against them were dropped.

About 20 Iranian women were also brought to a federal correctional facility in Manhattan, about 65 miles southeast of here.

Holmer Holland, chief correctional supervisor at the federal prison on Park Row Street in Manhattan, said that the women have refused any solid food. "They're taking sugar and water, "Holland said, and only at night.

Holland said the women are being examined by physicians, but no medical problems have developed because of their hunger strike.

He said the women have more freedom than the men, and are allowed to meet together in a common area where they can watch televison. He described them as "quite."

Holland said there have not been any Immigration Service officials at the facility to talk to the women so far.

Originally, Immigration Service officer Stanley Costello told reporter's that deportation hearings against the Iranians held here could begin as early as tomorrow (Monday), as soon as an immigration judge could be sent to the scene.

Today, however, John S. Drastal, deputy district director of the INS New York office, said that "the hearings will begin seven days after orders to show cause are issued."

An order to show cause, in Immigration Service jargon, is similar to a warrant, and requires an alien to prove that he or she is in the country legally on a valid visa. It was unknown late today whether such orders had been issued to any of the Iranians jailed here, but it appeared unlikely since, as of 3:30 p.m., prison officials said that the immigration officers had yet to interview any of the Iranians.

Drastal also said that the hearings, which would "possibly" be open to the press, would be held in the city where the aliens live. Presuming most of those arrested in Sunday's demonstration are residents of Washington, D.C., they would be transported back to the Distict for their hearings.

Michael Maggio, an immigration attorney representing some of the Iranians, said in Washington yesterday that he had received notice for hearings on eight of the Iranian women. The women would presumably be taken back to Washington for the hearings, Maggio said.