Engine - Poor Performance/Rough/Unstable Idle

Number 84-6 (Gasoline)-89 Date 9/85
Subject: IDLE ROUGHNESS OR POOR ENGINE PERFORMANCE CAUSED BY ABRADED NO. 3 SPARK PLUG WIRE

1984 FIERO
Some high mileage Fiero vehicles may exhibit idle roughness, an unstable idle speed, or poor engine performance, particularly during acceleration. Any of these conditions may be caused by a worn number three spark plug wire. This wire can be abraded by the intake manifold core plug due to spark plug wire movement in the area.

SPARK PLUG WIRE LOCATIONS:

To correct the condition, replace the single abraded plug wire. Use small diameter electrical nylon conduit to protect the wire at the point of contact. Tape the conduit ends to the plug wire to avoid slippage of the nylon conduit.