I have replaced the coil pack, spark plug wires, and all spark plugs with new ones. However, my 1996 Ford Winstar still experiences a misfire specifically at around 3000 RPM. The engine runs smoothly at idle. I am not seeing any diagnostic trouble codes (DTCs) on the OBD-II scanner. Could this be related to ignition system components or fuel delivery? Any advice on how to further diagnose this issue?
Now you need to know the cause. I know you said you replaced, but double-check everything! Spark plugs could be loose, damaged, or fouled. Plug leads might be arcing—look for stray sparks. Possible coil pack or high-tension (HT) ignition issues. Also consider fuel-related problems such as a faulty injector. Another possibility is cylinder compression loss—verify that Cylinder 1 has proper compression by comparing it to other cylinders. Check for combustion chamber leaks. Have you checked for any stored diagnostic codes? If not, scan the system with an OBD-II scanner to rule out underlying issues.
That's a frustrating issue—especially without any error codes. Make sure you've thoroughly inspected all connections and components.