The old truth is that you need three things for ignition - spark, fuel, and air (all at the correct time, of course).

If this was a running engine, and now has this problem, I would start with the primary wiring - distributor, coil, coil wire, plug wires and plugs.

If the engine has been out and you are now trying to start it, you are going to have to tell us more about what you have done.

Jim Paget
88 YJ with a few changes

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