Engine rough. One cylinder not firing?

[RayInStl]

I finally got the engine back in the ranger. She fired right up but isn't happy. I thought I got the timing wrong and did a bunch of fiddling with it.

Once I was satisfied it wasn't a timing problem, I decided to check to see if the cylinders were all firing. I pulled the pug wires one at a time. Each time the engine struggled when I unplugged the wire and recovered when I plugged it back in. Until I got to the last cylinder. There was no change in idle with the wire unplugged.

I then put a test light on it to make sure the wire was good. It lit up fine, so I removed the plug, grounded it, and got spark. Fearing the worst, I checked compression. 110 psi. Nothing to write home about, but should be more than enough to combust.

I'm at a loss. Compression, spark, fuel, and air. That's all it takes, right? If the other cylinders have fuel and air, this one should, right? I'm going to take the intake off tomorrow and make sure I didn't leave a shop towel in the intake port or something stupid like that. Anything else I should be checking?

This is an 83 2.3L and is carbureted, not fuel injected.

 

[alwaysFlOoReD]

Frayed wire? Cracked porcelain?

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[RayInStl]

Wires are new, plugs are not. I'll try one of the old wires and move the plug to a different cylinder and see what happens. Good ideas! Thanks!

 

[alwaysFlOoReD]

Also check firing order.

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[RayInStl]

Huzzah! It was the plug! I moved the plug to the first cylinder and the symptoms moved with it. I stole one of the 8 plugs out of my brother's 91 2.3 and everything smoothed out. I've got 4 new motorcrafts to go into it. Thanks for the suggestion! It's running better than ever.

 

[alwaysFlOoReD]

Good.

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