rough Idle

[petey_z24]

Ok guys,

89 Z24 2.8 auto. Whenever I start the engine and it is cold, it idles horriblle for about the first 30-90 seconds, then smooths out and runs beautifully. The problem is only when the engine is cold.

[Joe W]

A little more info would help here.When was the last tune-up,did the check engine light come on?

[Three_Fingers]

Coolant temp sensor/cold start injector/Intake air temp sensor-good places to start.

[petey_z24]

ok thanks for the replies
last tuneup was about 5k miles ago, labout a year ago, no check engine light