1991 pont gp 3.1l

1991 PONTIAC GRAND PRIX
167,000 MILES • 6 CYL • 2WD • AUTOMATIC
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SCOTTSAUTO
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  • 1 POST
vehicle has very bad surge at idle when hot, runs great when cold
Mar 18, 2011 at 4:32 PM
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JDL
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  • 16,098 POSTS
How long since a tune-up? Clean throttle-body and iac/idle air control. Any applicable mil codes? Maybe a vacuum leak after the vehicle warms up? Need something to point us in the right direction. I can look at rough idle in our database and the list is probably as long as my arm, many possible causes.
Mar 18, 2011 at 5:01 PM