Jake brake stang!!

Does it have any codes? The check engine light doesn't need to be illuminated for codes to be stored. How recently was the last tune up performed?

The TFI module mounted on the distributor is usually the culprit for a high speed miss on a warm engine. If the problem does not occur when the engine is cold, the TFI module is definitely suspect. You may need a special socket to remove the TFI module, but most auto parts stores will have one for $5-$7.

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Automotive Tools Specialty | Auto Mechanic & Technician Diagnostic, Testing Equipment | Thexton

Or you can grind down the outside of a 7/32" deep socket untill it fits.

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.