Hi there I'm new to the forum and need help plz I have a 1990 honda accord It runs great when cold (closed loop) or above 2k rpm things I have done replaced ect sensor under dizzy that talks to ecm replaced upstream 02 sensor tried two different coils both were used out of wreckers thought so may still be coil new plugs cap and wires cleaned egr passages tested egr functions properly and set timing today 15 btdc if I ease into throttle very slowly it runs anything more than a slight throttle it stumbles until it backfires and dies help me please