4.6L engine cranks over, no fire to plugs, will crank the next day, and after about three days will quit firing again after it is turned off, it does not fail when running, problem is when it is turned off, the next day the engine won't fire, hot battery, cranks over fast but no spark!

SOURCE: 92 deville car does not stay running after 1-2minutes

i know this sounds stupid but did you check the oil some caddys have a fuel pump shut off if the oil gets to low

SOURCE: car tries to crank but back fires

its a timing problem sounds like bad wires if you replaced them already then check the timing belt

SOURCE: 1991 eldorado wont start

So you put gas down the throttle body and it won't start. Sounds to me like you either have NO SPARK or your plugs are already fuel fouled. Even with you supplying the fuel. it still wont start. FYI, the FUEL FILTER is located by the R/R wheel, and the FUEL PUMP is located IN the fuel tank. Hope this helps

SOURCE: 1999 Cadillac Catera - 103,000 miles - cranks but no fire

Hello carol...from the symptons you describe more than likely it's the CPS (crankshaft position sensor.)
The CPS is a common problem on Cateras with these symptoms.
The sensor is a magnetic impulse type that sends a signal to the computer, the computer then triggers the fire signal. When the CPS gets weak, dirty or has low voltage the intermitten no starts occur. It will finally result in a no start at all...Please be aware that a lot of caddy dealers will and have overcharged customers for this common problem by ill advise and replaceing uneeded componets.
Good luck...i hope this helps and will fixya up.

SOURCE: 1998 STS won't start

If none of the gauges are or "idiot" lights are working then I'd start looking for a voltage problem. Like an ignition switch. If the lights are coming on and the scurity light is on steady or flashing then you would have a security problem.