Just got back from the rig time to drive the Vette, My wife said she hadn't driven it in 3 wks due to getting stuck one day because it wouldn't start. She had someone jump it off and said it started immediately . I drove to town today , It started no problem, then after leaving it sitting it wouldn't restart. I left it for about 10 mins, came back and she started first try????? Sound like a misread key to anyone else.
I'm not sure , knew that I'd get help here, also looking at it in the manuals , but maybe someone has a quik answer... Thanks.

 

Sure sounds like a VATS problem to me. Very typical when the key or the contacts in the ingnition cylinder get worn. If it is not a major concern you could get a bypass kit and never worry about it again. The reset after a bad read is about 10 minutes.

 

Might wanna try your extra key, or clean it with rubbing alcohol. I'd make sure that battery was fully charged first though.

 

Your description sucks. Do you mean by, "won't start", that it won't crank? or that it cranks but won't start and run?

 

Try this:
VATS measures the resistance of the pellet in your ign key and if it exceeds 5% from the stored value, it won't allow a crank nor the injectors to be pulsed to prevent push starting. If the value is not correct, you have to wait 6 minutes to try again. When it won't crank, jump the clutch safety switch (gear selector switch if automatic). Connect a voltmeter from clutch switch jumper to ground and see if there is 12v when you attempt a crank. If there is and no cranking, the starter solenoid on the starter is suspect. If no 12v, VATS is suspect. Next try your spare ign key as its pellet contacts aren't worn like your everyday key. Continued problems require a test of the contacts in the ignition tumbler. Remove the hush panel above the drivers feet and locate the two wires from behind the steering column (white on my 87) that go to a 2 pin connector. With the ign key inserted, unplug the connectors and measure the resistance across the wires from the steering column. They should measure the same resistance as the pellet. If over 13k ohms, you need a new ignition tumbler which has new contacts that make connection to the pellet. You can temporarily bypass VATS by connecting a fixed resistor the same value as your pellet across the 2 pin connector going into the wiring harness (goes to VATS module). You can use a 1/4 watt 5% resistor from Radio Shack. Dont' permanently bypass VATS because 99% of thefts are done by bashing the column and jumping the ignition.

 

This is exactly why I work on my vette in my time off. It doesn't talk back to me. After 28 days of trying to supervise Nigerian roughnecks while drilling offshore , I just want to relax and fix/improve my car. So I'm really , really sorry my description sucks, Your response also, sucks.
However, your second reply was extremely informative and helpful , I am currently looking into a vats problem. And yes, it has symptoms of a theft deterent problem when I turn the key ,Nothing, NADA , simply sits there. come back later, Fires right up , no starter stumble or any other symptoms. Both my keys show quite a bit of wear, maybe I should just try a new, key. Put new brakes all around today, so didn't look into this today , also didn't have any not starting issues.. Thanks for the info everyone..