Diagnostic Aids

WARNING: This page is about a different car, the 1995 Ford Explorer and 1995 Ford Aerostar. However, it is still accessible from the selected car via links, so may be relevant.

An engine analyzer is used to diagnose problems in secondary side of ignition system.
Visually inspect engine compartment to ensure vacuum hoses and spark plug wires are properly routed and securely connected.
Examine all wiring harnesses and connectors for insulation damage and burned, overheated, loose and broken conditions.
Ensure battery is fully charged and all accessories are turned off during testing.
Use an engine analyzer or lab scope and EI Adapter (Rotunda 007-00044) in these testing procedures.

Fig 1: EI Secondary Voltage Scope Pattern ID (Aerostar & Explorer)