HOUSTON, Jan 12 (Reuters) - TotalEnergies on Friday restarted the large crude distillation unit (CDU) and large vacuum distillation unit (VDU) at its 238,000 barrel-per-day (bpd) Port Arthur, Texas, refinery, said people familiar with plant operations.

The refinery's two CDUs and two VDUs were shut on Thursday following a malfunction on the gasoline-producing fluidic catalytic cracker (FCC), the sources said. The CDUs and VDUs convert oil into feedstocks for all other units at the refinery.

A TotalEnergies spokesperson was not immediately available to discuss operations at the refinery.

The 76,000-bpd FCC-2 was operating on Friday, the sources said. During a malfunction on the catalytic cracker on Wednesday and Thursday, production and steam use was reduced on several units, TotalEnergies told the Texas Commission on Environmental Quality in a regulatory filing.

There is only FCC at the TotalEnergies refinery.

The 150,000-bpd ACU-1 CDU and 60,000-bpd VDU-2 restarted on Friday, the sources said. ACU-1 is one of two units operating at atmospheric pressure that begins the refining process by converting crude oil into feedstocks for all other units.

VDU-2 receives gunky residual crude oil from ACU-1 and, operating at vacuum pressure, breaks it down into feedstocks for other units.

The 40,000-bpd ACU-2, as well as the 51,000-bpd VDU-1 remained idled on Friday, the sources said.

FCC-2 has

struggled

to reach full production since completing a three-month overhaul on Nov. 20, sources have told Reuters.

ACU-2 and VDU-1 remained shut until mid-December as FCC-2 was raising its production level.

The FCC-2 overhaul included replacement of the 1.3-million-pound (590 metric ton) reactor on the unit. (Reporting by Erwin Seba; Editing by Leslie Adler and Marguerita Choy)