So you have this engine that won't start, you have checked the compression with a valid gauge and it's good, you are ABSOLUTELY CERTAIN that it isn't flooded and when you pull it over with the plug held against the cylinder you get a nice spark but no matter what you do the damn thing won't even fire and your arm is getting tired. It takes more energy to fire a plug under compression than in open air so a good test is to gap an old plug to at least 0.1" and if it will fire that in open air, it probably will fire a normal gap in the engine. Did you have to get the engine spinning over real fast to get a spark? Every ignition system has a minimum rpm that is required to produce a spark and if the sensitivity of the trigger circuitry in the module has changed this can be a problem, so you want to check the spark at cranking speed. Do you have an in-line tester that you trust? I prefer an automotive type timing light, they are cheap and give a bright light that can be easily seen, if you know a mechanic they will probably give you one, as they are totally useless on modern vehicles. With the tester hooked up and the plug in the engine, you should get a flash every time you pull the engine through compression. Maybe the timing has slipped if the flywheel key has sheared (rare but does happen). A rough indication that the timing is still good, is to rotate the engine in the normal direction and check to see if the magnets in the flywheel line up with the legs of the coil just before the piston comes up to TDC. If it looks suspicious, you will have to pull the FW to check the key. If you have a timing light, it can be used to check the timing as well as just the presence of spark (subject for another post).
