Intermittent Problem Diagnosis
WARNING: This page is about a different car, the 1996 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
Intermittent fault testing requires duplicating circuit or component failure to identify the problem. These procedures may lead to the PCM setting fault code, which may help in diagnosis. If fault code not present, go to CIRCUIT TEST Z in TESTS W/CODES - 5.0L article.