Timing light not picking up spark

[Scott26]

I know i have a dead cylinder on #5 . I got my timing light to test if it had spark to it and it only lights up about every 5 seconds. all the other cylinders light up normal.if the plug is fowled or carbon bridged will that stop the timing light from lighting up??or is it from the distributor. So if the timing light does not pick up spark or light up does that mean its a distributor problem or from the spark plug not working?.

[cableguy0]

how old are the tune up parts? A bad cap or wire is the most likely culprit. If you need a cap and rotor you likely need plugs and wires too. Tune up parts should always be replaced as a set. Bad tune up parts will kill a coil or module from overworking it.

[Scott26]

The cap is about 6 months old or so. The wires are new .but the plug keeps on getting carbon and oil build up on it about every two days so I know it's not firing I'm wondering if it's a ignition problem instead of a wore out engine that was causing the miss fire
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[cableguy0]

Check the compression on that cylinder. If its oil build up You likely have an engine issue. Nothing can survive a bunch of oil in the cylinder. If you replace the plug does it run ok for a while?

[gchemist]

Replace the wire with another cylinder wire. See if it does the same thing. If it does, the problem is in distributor. I would replace the cap. Since the cap is off, have the ignition module tested. Same for the coil. New distributors are fairly priced.