Won't start problem

1989 Olds 98, 3.8V6, 4spd auto.
Difficulty twice turning over, especially when warm and idleing for a short time after being driven a while. Finally quit and wouldn't start at all, left down all day, then started (Barely) and got it home. I couldn't hear the solenoid click, but someone else standing outside told me they heard the click.
I replaced the battery w/one from another vehicle, still no good. Examined battery cables (especially the huge one that goes to the starter) they look pristine.

Replaced starter being careful to include spacer on new unit, tightened everything up. Starts and ran fine. Yeah !!

my car wont start and i need help i have replaced the starter and battery and still it wont start

I just had this problem with my 87' Regency. It was running perfectly. whentinto a stoer, cam out. wouldnt start. we finally got it to start but it ran incredibly rough. got it home, did the same thing to me for about 2 weeks, had to drive a different vehicle. it finally completly died. it wouldnt fire correctly and only partially, you could hear a weak bang from each of the cylinders and smoke was coming out of the screws that hold the air filter in place. I did a tuneup on it, same thing. Auto_tech teacher thoguht it was teh fuel pump, i thought it made sense. so i got it towed to the shop. They found out it was the Timing chain, it had slip a couple teeth out something. a 500$ job, should have been about 800$ but my dad is the manager of an auto parts store and he knew the macanic so i got a nice break on the price. hopefully it something a lil cheaper then this but i would look into it.

jsut my 2 cents. hope it helps.