Hey, I have a 91 deville I've had for about 3 years It worked great at first, about a year ago I began to have problems when I would drive it for a while I would have trouble when parking and trying to restart it I would get nothing at all, I would have to let it cool down and then would restart like nothing,until one day it simply would no longer start, i hadit scannedby a mechanic could not find anything other than it needed 3 injectors replaced(would that prevent it from starting?), I bought a new battery and it would crank but not start, the chip on the key checked out ok and no trouble found by the electrician, I replaced spark plugs, wires, rotor, and nothing so it sat for about 6 months, about 3wks ago I decided to work on it bought a new battery and itSTARTED like nothing was wrong with it, later that night it simply would no longer start! crank but no start! so I replaced the starter and still nothing ANY IDEAS??

 

Crank position sensors were famous for causing the car to quit. If it cranks, you need to verify spark and fuel are getting to the engine just like any other car. If it wont crank, then thats a whole different issue, battery, VATS key or poor grounds.

 

I had a similar problem on my '91 some time back. It would crank but not start...a couple of minutes or a couple hours later it would fire right up. I'd go days or weeks without a problem then it would happen again. No codes. Dealer could not isolate problem. Cleaned up battery terminals and left them disconnected for several hours (re-boot the computer?) and haven't had a problem since.