91 Cadillac SeVille - 4.9 liter engine --- car often will not start. When key is turned you only hear a click. Usually it starts ofter 3 or 4 attempts. Sometime there is no click and the car will not start at all. However, if I wait, several minutes to several hours it will start as described above. I replaced the starter with solenoid 4 times ( 3 rebuilt then a new starter ) . I replaced the pos and neg battery cables. -- problem is unchained. My local mechanic and the Cadillac dealer are stumped. Car is, otherwise, in good condition.