What was found
PHX - ENG SHUTDOWN - FLT 656 - LG 7289288 - STARTED RT ENG, 570 TICK MARK DID NOT DISAPPEAR AFTER ROLLBACK, ENG RAN ROUGH AT IDLE. ABNORMAL AIRFLOW IN COCKPIT WITH PACK OFF, START SWITCH DEFAULTED TO AUTO NORMALLY, DUCT PRESS NORMAL 20 PSI AFTER START, SHUT ENGINE DOWN. MAINTENANCE REMOVED AND REPLACED THE ENGINE SPEED CARD IAW AMM 77-12-034, BITE CHECK GOOD. MAINTENANCE ALSO REPLACED THE N3 TACHOMETER IAW 77-12-02-4.