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Q: Why would a truck crank but not start until a plug wire is removed?

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My truck would not start this morning. It would turn over but wouldn't start. I pulled the plug wire to test for a spark, got it to spark then it started. Shut the engine off, plugged the wire back in, waited a few minutes and it wouldn't start again. Pulled the wire again, and it started yet again. What would cause it to do this?

My car has 130000 miles.
My car has an automatic transmission.

The engine may have a shorted spark plug that is shorting the coil out. I would recommend replacing the spark plugs first then replace the coil pack if it continues to not start. If you need help with this, a certified professional from YourMechanic can diagnose the starting issue and help perform any of these services for you.

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