Engine will not start

have you scanned for codes and checked fuel pressure with a gauge? if not do so auto parts rent the gauge. the chain could have jumped but there is no mileage that comes through on new site so I can't say for sure on that.

IMAC
It has still not shown any codes. It has about 110,000 on it.
I have not checked the fuel pressure other that relieving the pressure at the connection point for the gauge. You can hear the pump turn on at the tank fill. No weird noise just a nice even hum. I guess the next step is going to be loan-a-tool a fuel pressure gauge.

HMAC300
Update. Went out today to hook my OBD-LX to it as see if I could get any readings that would give me a clue as to what was going on. It seemed to be dragging when I tried to start it. Again, it seemed to try but would not start. The reading on the battery. Was about 11 volts so I put my charger on it. After about 10 minutes, I tried to start it again. It still seemed to try but would not catch. This time, I gave it full throttle thinking that if I could get it to run, I could make it hit the rev limiter so it could "learn" the new new crankshaft & camshaft position sensor. Well.... that got it to start. I left off and it was running rough. So, I gave it some gas to hit the limiter and let off. After that it ran fine.
But, to make sure, I took it up to have the battery & alternator checked. The alternator checked out fine but the battery was bad. My son said it runs better now. Before, he said it didn't seem to have much pick-up.
I want to make sure I said thank you for you input. So.... THANK YOU!!!!!

bad batteries will do that not enough voltage makes the computers do screwy things. I should have told you to do that in first reply as well.

Oh well. I still think the sensor was part of the problem since it seems to be running better than before. But yes, low voltage to a computer can cause some WEIRD things on a computer.
THANX again!!!!

I took the wiper motor and assembly out and put it all back together and now my car will crank but not start.

Go over the areas where you worked and look for a missed wire connection. Look to be sure nothing was knocked loose by accident. If you had the battery disconnected you may have triggered the security feature. Try a reset and see if it helps.
Generic system reset.
https://www.2carpros.com/articles/how-to-reset-a-security-system

My LaSabre just quits sometimes when driving. Usually you can slip it to neutal and restart immediately. This has happen many times in the last year. Took it to Buick Dealer and they ran Dynostics on it but could not find the problem. Now, sometimes it refuses to start at first but than after turning inition on and off several times and trying to start it will start.

Has the check engine light come on? If not, I would recommend starting with checking fuel pump pressure. Let me know if you need directions.

Joe