Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1991 Ford Explorer 2D Utility, RWD, AutomaticFACTORY OEM SERVICE PROCEDURE
Test Equipment
Following test equipment is necessary to complete DIS ignition system tests.
- DIS Diagnostic Cable (Rotunda 007-00044)
- Spark Tester (Neon Bulb Type)
- Digital Volt-Ohmmeter (DVOM)
- Remote Starter Switch
- Breakout Box (BOB) With 2.3L DP DIS Overlay
- High Voltage Spark Tester (A spark plug with a broken side electrode is not sufficient to check for spark and may lead to incorrect results.)
- Tachometer
- Inductive Type Timing Light (DO NOT use "advance knob", if equipped, as it will not work correctly with DIS Ignition Systems.)
- Test Light (LED Type) Or Logic Probe (LED Type)
CAUTION:
A 12-volt incandescent (high voltage) test light SHOULD NOT be used to test CID or PIP circuit signals. It will load the circuit and may cause incorrect measurements or faulty DIS/ECA operations (engine stall).
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.