Idle Speed Control (ISC) Valve
- Unplug ISC valve connector. Measure resistance between "B+" terminal and "ISC1" and "ISC2" terminals. See Fig 1. Ohmmeter reading should be 16-17 ohms. If not replace ISC valve.
- Apply battery voltage to terminal "B(1)" and terminal "B(2)" while repeatedly grounding terminals "S(1)", "S(2)", "S(6)", "S(4)" and "S(1)" in sequence to cause valve to close. See Fig 1.
- Apply battery voltage to terminals "B(1)" and "B(2)" while repeatedly grounding terminals "S(4)", "S(6)", "S(2)", "S(1)" and "S(4)" in sequence to cause valve to open. Replace valve if not operating properly.
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