1997 f-250 4x4 5.8 ,eng. after starting goes into high idle and will not kick down.
Check the ISC unit, it could be dirty and stuck in a fixed position, also make sure your throttle body is clean, sometimes the throttle body air plate gets crud in behind it and holds the plate open too far to achieve a good idle. If all of that checks good and you still have a problem you will have to access the ECM's diagnosis to get the codes.
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