I have a 3800 series II SC transplanted into an 86 Fiero. It has 96K on it.
Since the transplant it has not run well above 4000 RPM. It will buck and miss at the higher rpm and the MIL light will flash but it seldom sets a code. The flashing will continue for a while at slower speeds, then go out.
The one time it set a code was "Random Misfire". The plugs were changed from new AC 41-101s @ .060" to Auto Lite AP104s @ .050 gap also new Accel wires and coil packs. This helped but my miss still persists. Can't find any vacuum leaks, nor do I see any indication of arcing in the ignition system. It runs well at or below 4000RPM or so.
Any sugestions