What was found
DURING TAXI AND AFTER BOTH ENGINES START, FWD EQUIP VLV ILLUMINATED, DID ABNORMAL, DID NOT CLEAR. A/C RETURNED TO BLOCKS (BTB). AT THE GATE, AFTER APU RUNNING, IT DID CLEAR. MAINTENANCE DEFERRED PER MEL 21-58-1-1, MAINTENANCE PROCEDURES COMPLIED WITH, PLACARD INSTALLED. AC REMAINS NO ETOPS. MBCB 03/29/26. REF LP 39307-93/1. AIRCRAFT RETURNED TO SERVICE.