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Q: Number #1 cylinder misfire?

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Hi, I have a 1999 ford crown Vic 4.6 .The #1 spark plug black with gas, I put new plug coil and new injector . 2miles later black and car smells gas. Someone told me it could be a bad Pcm but only the one plug, all the others are good. Help!
My car has an automatic transmission.

Hi there. As you already know, replacing components without proper diagnoses can expensive and time consuming without resolution. Assuming, the engine is mechanically sound, good cylinder compression and valve train properly opening and closing, circuit tests need to be performed. A pulsed electrical signal should be seen at the injector connector and ignition coil connector, during engine cranking. There are noid lights available for testing both signals. It is fairly common for the retaining tab on the coil connector to break, thus not securing the connection to the primary side of the ignition coil. I recommend having your vehicle’s #1 cylinder engine misfire be diagnosed and repaired by a certified technician, such as one from YourMechanic.

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