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.
Retard Components (Capri Turbo)
Positive pressure to the vacuum advance cylinder on the distributor retards ignition timing. The ECA also retards ignition timing when it receives a signal from Knock Sensor (KS) and related circuitry.
- Disconnect and plug hoses at distributor. Connect timing light. Start engine. Determine and record ignition timing. Tap intake plenum with plastic mallet while monitoring ignition timing. If timing retards, Knock Control (KC) circuitry is okay. If timing does not retard, go to next step.
- Unplug KC sensor service connector, located near ECA. Tap intake plenum with plastic mallet while observing ignition timing. If timing does not retard, go to step 4). If timing retards, go to next step.
- Reconnect KC service connector. Tap intake plenum with plastic mallet while monitoring ignition timing. If ignition timing retards, replace knock controller. If ignition timing does not retard, go to next step.
- Unplug KC service connector. Temporarily install known good knock sensor. Tap intake plenum with plastic mallet while monitoring ignition timing. If ignition timing retards, replace knock sensor. If ignition timing does not retard, go to next step.
- Turn ignition off. Connect BOB. Ensure vehicle power (VPWR) and ground wires to knock sensor are okay. Check all knock sensor wiring for shorts or opens. If wiring is okay, replace knock sensor.
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.
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