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OK, sounds like we are good on the fuel side. The issue is going to be electrical. If you are sure, the battery, ignition switch, and starter are all good, the only other components left are the battery cables, the starter relay, and the neutral safety switch. The relay, I would just replace, for about $12, it is good insurance. If that doesn't do it, check the battery cables, make sure both connections at the battery terminals are good and tight, then check the ground cable, make sure it tight where is connects to the body / frame. Next will be the positive cable connection at the starter itself. Make sue it is tight, and there is no corrosion anywhere. If good there, move on to the neutral safety switch. It is also sometimes called a transmission range sensor. If this is faulty, the PCM won't know the trans is in park and will keep it from starting. The only other possibility is the crankshaft position sensor. If this is not sending a signal to the PCM, the engine will not start, but you will get a check engine light if the crank sensor is faulty. If all of these are good, the only other possibility will be a faulty PCM. See below for component locations: