After decisively ousting Andrew E. Jenkins yesterday, members of the D.C. school board expressed great relief that his tenure at the helm of the city's schools had ended. But they won't be able to relax for long.

The board has blamed Jenkins for much of what has gone wrong in the 81,000-student school system during the last two years. Its 8 to 3 vote eliminates that excuse, yet enormous problems remain.

Months of debate on Jenkins has split the city's principals and teachers, its parent leaders, even the system's top administrators. And it has left in doubt whether work on the system's most serious issues can proceed smoothly in the coming months.

"This is bound to cause great disruption now," said Frank Bolden, president of the Council of School Officers, which represents city principals.

Jenkins leaves behind a system burdened with crises. At most grade levels, student achievement lags behind national averages. It is estimated that four of every 10 city students quit before graduating. Among those who stay, the average grade-point score is 1.7, a low C or high D.

Although in all corners of the city some schools are showing remarkable success, there is growing concern that confidence in the system among parents and the D.C. Council -- which finances the city's schools -- is diminishing.

In the last year, the system has been criticized for not being able to determine its exact enrollment -- or say why it's sinking. It also has not had much luck improving the condition of school buildings; its backlog of repairs exceeds $150 million. Neither of those problems has been helped by continuing upheaval in the top ranks of the schools' administration and among principals.

Since fall 1988, the school system has removed or reassigned nearly 100 principals -- a total that far exceeds the turnover rate in Washington's suburban school districts.

"In many ways, our school system is failing the kids," said board member Karen Shook (At Large). "We're losing ground, and we cannot afford to move backward anymore. We have a very large plate of problems to solve."

In his fiery departure, Jenkins blamed the 11-member board for many of the school system's ailments. He said that he and his staff were handcuffed by the board's political whims and he accused its members of being more interested in "power, control and property" than in educating students.

It's now entirely in the board's hands to prove him right or wrong. Members already have begun searching for his successor, and have vowed to find a forceful leader from outside the school system. The board also has a widely praised agenda for change that was assembled last year by 60 of the city's most prominent business, education and religious leaders.

So far, it has not implemented many of that group's proposals, which included boosting teachers' and principals' pay, extending the school day and school year, revamping math and science instruction, expanding early childhood programs, having the education program better reflect the contributions of all cultures and drastically reducing the size of the bureaucracy.

One restraint is money, but there are also questions among some parents about the board's will to act. "This has indeed been a very difficult day," board member Eugene Kinlow (At Large) said yesterday. "But it's time to move very seriously toward the future."