My 1997 Hyundai Tiburon has a cylinder thats not firing?

[brockl]

I just changed the spark plugs a week ago and not my car makes a clunking sound when i press on the accelerator and the engine/exhaust makes my car vibrate. It seems to be my first cylinder that's not firing and the new spark plug tip in the 1st cylinder is already covered black while the other ones look new. It was driving alright just a loss in acceleration and the loud clunking noise

 

[dathinman8]

Spark plug wire is not connected properly to the spark plug or the coil. Check both ends for proper connection. Another possibility is that the spark plug gap is closed too much and the plug isn't firing--- pull the plug and recheck the gap. If you didn't check/set the gap of each plug when you installed them-- you may want to check/set them all. Sometimes the gap gets closed due to being dropped or bumped during installation or shipping. Most plugs come pre-gapped close to specs from the factory, but they should always be checked and set before installation.

 

[michaelB]

The first thing to have checked is the cylinder compression in all cylinders. All should be within 10 or 20 pounds of original specs, and within 10 pounds of each other...then maybe a plug wire has gone bad...