I have a 1999 tahoe 4x4 5.7l with 214000 miles. I keep having to replace the ignition switch due to starting problems. It starts missing and running bad, then suddenly won't start. When I crank it it won't try to fire untill I let off the key. The next day it will start and smoke oil smoke for a minute but still misses and runs bad. If I replace the ignition switch it will start and run fine everytime for about two weeks and then then problem starts again. The ignition cures it everytime for about two weeks but is too expensive and takes too much time replacing it. What is the problem, what is the cure, and how do I get g.M. To pay for it or cure it perm? Never any oil smoke after replacing the ign. Switch.