1990 Chrysler Le Baron starting issue. Again

I went thru some major questions and answers for this car already. Well, now I'm back to square one again. I couldn't get it to start for about three months or so, therefore I started changing parts left and right that had to do with fuel or starting. This is what has been changed in it. I replaced the fuel filter. Fuel pump relay. Battery. Had the starter tested ( which tested strong). And still it would not start. Finally, I figured out that my problem was the neutral safety switch. Which I also replaced. Well. The car was running for about a week. Now.I'm back to where I started. It will not start again, all it does is turn over but does not want to engage and keep running. All that happens is the starter cranking and nothing more.