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Q: Idle jumps up and down

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When I start the truck, the idle jumps up and down and then sounds as if it wants to shut off. Sometimes it will cut off when I'm at a light, and the Check Engine light comes on.

Hello. If the Check Engine Light is coming on, then the first thing that would be helpful would be the computer codes. These can be retrieved with a scan tool. A mechanic would scan the computer first to get these codes to see what the computer is seeing as the problem. It sounds like you may have a faulty air flow sensor or you might need to have the vehicle tuned up. It may also be a faulty vacuum hose on the engine allowing air to enter the engine unmetered. If you do not have a scan tool to check the computer then I would enlist the assistance of a certified mechanic that can diagnose your Check Engine Light and move forward with repairs for your idling issue.

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