IF the timing has jumped, starting will be difficult and even have some flaming spitbacks, as it turns over. To verify, you can advance the timing one full plug wire's rotation advanced. If it starts easier and no spitbacks, that can be confirmation. Saw that "advance the distributor one notch" work as the old-line Chrysler service manager diagnosed a TX DPS car back in 1976 or so, at the local Chry dealership.
When my '80 Newport's timing chain failed, it had been running a bit funky for a day or so prior. No tuning would help it, so I suspected it might have been the computer, but it was not (after I swapped in a new Chry reman unit). Then, when driving, I slowed to make a u-turn and it died and would not restart.
One reason I consider ANY OEM timing sproket with over 80K miles on it "on borrowed time". Even if the engine might be running nicely, it's just a matter of time before you might be stranded somewhere, hopefully with cell service. Especially if the car pre-dates about 1990s, fwiw.
Just some thoughts,
CBODY67
