AN MD80 AT FL280 SLOWED BELOW HOLDING SPEED AT HOLDING ENTRY AND APCHED A STALL. THE ENGINES WERE OVER BOOSTED BUT STALL WARNING DID NOT ACTIVATE.

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ENRTE TO ZZZ I WAS PNF/PLT MONITORING. CAPT WAS PF; UTILIZING AUTOPLT IN NAV AND VNAV MODES. OUR AIRSPD WAS 245 KIAS; SLOWED DUE TO TFC INTO ZZZ AND ANTICIPATED HOLDING. ATC CLRED US DIRECT TO ZZZZ2 INTXN AND THE ZZZZ1 ONE ARR; UPON REACHING ZZZZ1 HOLD AS PUBLISHED AND CLRED US TO DSND TO FL280. CAPT PROGRAMMED FMS TO GO DIRECT ZZZZ2 INPUTTED THE HOLDING PATTERN AT ZZZZ2 AND INITIATED A VNAV DSCNT TO FL280. I VERIFIED THE CORRECT INFO WAS ENTERED FOR THE HOLDING PATTERN AND VERIFIED THE DSCNT TO FL280. ACFT REACHED ZZZZ2 INTXN AND BEGAN EXECUTING A DIRECT HOLDING PATTERN ENTRY WHILE AT THE SAME TIME LEVELING THE ACFT AT FL280. AS WE PASSED OVER ZZZZ2 DURING THE HOLDING PATTERN ENTRY; THE AUTOPLT COMMANDED AN FMS BEST HOLDING SPD OF 235 KIAS; AND THE ACFT BEGAN TO SLOW. WHILE SIMULTANEOUSLY LEVELING OFF AND SLOWING TO 235 KIAS; THE AUTOPLT COMMANDED A 30 DEG BANK TO EXECUTE THE HOLDING PATTERN ENTRY. AT THIS TIME THE AIRSPD BEGAN TO DECAY BELOW 235 KIAS AND SOME TURB BECAME NOTICEABLE. AS I EVALUATED THIS; I WAS MONITORING THE BANK AND AIRSPD DECAY AND JUDGED THE TURB TO BE PRE-STALL AERODYNAMIC BUFFETING. AT THE SAME TIME I WAS GOING TO BRING THIS TO THE CAPT'S ATTN; HE ALSO NOTICED THE BUFFETING AND SAID; 'I DON'T LIKE THIS; WE'RE TOO SLOW.' HE COMMANDED A HIGHER AIRSPD USING THE FMS OVERRIDE FEATURE OF THE MODE CTL PANEL. THE AIRSPD DID NOT INCREASE; AND THE ENGS SEEMED SLOW TO ACCELERATE. CAPT MANUALLY ADVANCED THE THROTTLES TO ACCELERATE AS I CONTINUED TO MONITOR THE FLT PATH AND AIRSPD. WE WERE LEVEL AT FL280; BEGINNING TO ROLL OUT OF THE TURN; AND AIRSPD WAS STABLE AT APPROX 230 KIAS BUT NOT INCREASING. CAPT ADVANCED THE THROTTLES FURTHER AND MENTIONED THAT THE ENGS DID NOT SEEM TO BE RESPONDING. I SCANNED THE ENG GAUGES AND SAW THAT WE WERE EXCEEDING ENG LIMITATIONS. FROM THE GAUGES; IT APPEARED THAT WE WERE EXPERIENCING COMPRESSOR STALLS. FLT ATTENDANTS LATER CONFIRMED THIS BY RPTING LOUD BANGING OR POPPING COMING FROM THE ENGS. I TOLD THE CAPT THAT WE WERE OVER-BOOSTING THE ENGS. HE RETARDED THE THROTTLES AND THE ENGS BEGAN TO RESPOND NORMALLY. THE ACFT BEGAN TO ACCELERATE. I ESTIMATE THAT THE ENTIRE EVENT TOOK 30 SECONDS FROM INITIAL AIRSPD DECAY TO RECOVERY. WE REMAINED LEVEL AT FL280 AND IN THE HOLDING PATTERN THROUGHOUT THE EVENT. ATC SEPARATION WAS NEVER COMPROMISED. AFTER RECOVERY AND DETERMINING THE ENGS WERE FUNCTIONING NORMALLY; WE MADE A NORMAL APCH AND LNDG AT ZZZ. MAINT WAS NOTIFIED AND MET THE ACFT; WHICH WAS TAKEN OTS FOR INSPECTION. I BELIEVE THE CAUSE OF THIS INCIDENT WAS THE SIMULTANEOUS OCCURRENCE OF THE LEVELOFF; 30 DEG BANK TURN; AND AUTOPLT DIRECTED SPD REDUCTION. THE MD88 AUTOMATION DOES NOT PERFORM WELL WHEN A LOT OF STRESS IS PUT ON IT. THE FMS COMMANDED A SPD TOO SLOW FOR THE BANK IT COMMANDED FOR THE HOLDING ENTRY AND THE AUTOTHROTTLES DID NOT PREVENT THE AIRSPD FROM DECREASING BELOW THE COMMANDED SPD. I BELIEVE THIS INCIDENT COULD HAVE BEEN PREVENTED BY USING FMS OVERRIDE PRIOR TO THE HOLDING ENTRY. THIS WOULD MAINTAIN A HIGHER AIRSPD THAN THE FMS BEST HOLDING SPD. HOLDING THE 245 KIAS; WHICH I BELIEVE WAS THE CAPT'S INTENTION; WOULD HAVE PROVIDED US A GREATER STALL MARGIN FOR THE HOLDING PATTERN ENTRY. IN ADDITION; THE CAPT SHOULD HAVE DISCONNECTED THE AUTOPLT AND LEVELED THE WINGS WHILE LIMITING THE PWR TO TOGA THRUST; AS OPPOSED TO ALLOWING THE AUTOPLT TO ROLL OUT OF THE TURN AND OVER-BOOSTING THE ENGS. I SHOULD HAVE DIVIDED MY ATTN MORE FROM MONITORING FLT PATH AND AIRSPD AND CAUGHT THE IMPENDING OVER-BOOST AND BROUGHT IT TO THE CAPT'S ATTN.