Will not start?

So for a while when it rained occasionally it wouldn’t start without jumping it off. Flash forward most recently the hood flew up on me just as I was starting to pick up speed after leaving home. Took the hood off to change or fix the hinges and hubby noticed a scrubbing sound when driving and braking so changed out the pads and rotors. Well, he didn’t get it all the way back under the carport and thus Brutus isn't starting. With much aggravation we (yes, we) got the distributor cap off and fully cleaned it noting no water present. So, I changed all the fused a I had replacements for and still it won’t what I call catch he says start. Just turns. About to go change out the plugs and wires and cap and rotor and just in case wanted other things to try if this doesn’t work. FYI hubby bought it brand new in 2000 right after he graduated from the cat diesel school in Nashville. So, it is very important to us. Especially since I first met him like two weeks after he got it. So, advice is greatly appreciated