92 Bonneville cuts out and intermitantly starts
 

I have an issue with92 Bonneville. The problem is very intermitant. Occassionally it cranks fine but no start. And occassionally it justshuts offwhile driving or pulling up to a stop light, but it restarts. When it doesn't start - I spray WD40 on the coil pack and wires, wait about 10 minutes and it starts. The mechanic I have taken it to says the codes indicate the problem is in the anti-theft system, but unable to locate. This is a model that has chips in the keys, I think I have the same problem with both keys though. Has anyone had a similar problem. The car has 230,000 miles and I'd hate to get rid of it just as I am getting used to it - I have owned it for all of about 5,000 miles, and besides after refinancig a couple of times I still have about 6 ore payments before its mine! Just kidding about that, but has anyone had a similar issue about the no-start/shutting off issue? Is this the same issue or do I have two issues? Many thanks!