Section 33 (Engine Controls - Basic Testing 4.0L): Introduction
WARNING: This page is about a different car, the 1996 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The following diagnostic steps will help prevent overlooking a simple problem. This is also where to begin diagnosis for a no-start condition.
The first step in diagnosing any driveability problem is verifying the customer's complaint with a test drive under the conditions during which the problem reportedly occurred.
Before entering self-diagnostics, perform a careful and complete visual inspection. Most engine control problems result from mechanical breakdowns, poor electrical connections or damaged/misrouted vacuum hoses. Before condemning the computerized system, perform each test listed.