Probably lots of folks more qualified than me to answer this question, but...first, how do you know it's an ignition problem? Does the engine turn over (crank)? If it does, use a timing light to check for a spark. If you don't have one, take out a sparkplug, hold it against a ground, and see if you get a spark when somebody cranks the engine over (wives are GOOD for this kind of stuff). If you get a spark, check the timing. Turn the engine 'till the timing mark is at 10 deg. BTDC (right-most point of timing mark is Top Dead Center. Each point is 5 deg. advanced). Then pull the cap off the distributor and see if the rotor is pointing at #1. That's a ballpark timing check. If not, rotate the engine one turn and check again. If that looks OK, you may have fuel problems, or worse. If the engine doesn't turn over, then forget everything I just said and we'll go from there.