1986 corvette not starting sometimes
Nothing more to add but…this might help.
https://www.corvetteforum.com/forums...post1594754928
Nothing more to add but…this might help.
https://www.corvetteforum.com/forums...post1594754928
Thanks for the reply
It must be the #1 key. I have 523 which is #2.
"Yeah measuring from the wires I’m getting .401k or 401 ohms" That is exactly a #1 key
.
Last edited by Vets-Vet; Mar 7, 2026 at 08:07 AM.





The SECURITY light has no association with "VATS" or cranking, or fuel enable in a 1986-1989.
I would double-check that you do or do not have Code 46. Code 46 will only be present if the "resistance" is currently not correct. Code 46 is not a stored code. If it didn't start, then it does, and you check for Code 46 to see if that was the cause, Code 46 will not be there from the prior event.
Get a $23 timers.shop VATS eliminator Signal Generator. It connects to (3) wires all available at the VATS module behind the passenger side breadbox, or at a connector under the RH dash. Eliminates any "VATS" problems or misdiagnosis permanently.
EDIT: Where do the wires from that button under the ashtray go? That could be a "Ghost Switch". Ghost Switch systems are normally incorporated into an existing switch that needs to be manipulated after key=on to activate a circuit that allows the engine to crank or start. These devices are usually a relay array that latches upon activation, and resets when the key is turned off. If that button goes to a relay or relay array, figure out what car circuit the relay(s) are interfaced into.
Personally, I interface my ghost switch systems into the ECM "turn on" wire, usually a pink/blk. The indication to the driver of the ghost switch status is the Service Engine Soon light. If the key is on, but the SES is off, the ghost switch hasn't been activated. Something to know about. The "hidden button" used to do 'something'. If I was working on a car with the history and issues yours has, I'd want to know what that 'something' is/was. .
Last edited by IHBD; Mar 11, 2026 at 12:37 PM.
What do you have for a cylinder now? A brass work key with a VATS cylinder or maybe a GM correct blank being used?
If a #1 bypass is used, might you still have issues? Maybe. IHBD's mention of the 'timers shop' eliminator is a very valid suggestion.
The SECURITY light has no association with "VATS" or cranking, or fuel enable in a 1986-1989.
I would double-check that you do or do not have Code 46. Code 46 will only be present if the "resistance" is currently not correct. Code 46 is not a stored code. If it didn't start, then it does, and you check for Code 46 to see if that was the cause, Code 46 will not be there from the prior event.
Get a $23 timers.shop VATS eliminator Signal Generator. It connects to (3) wires all available at the VATS module behind the passenger side breadbox, or at a connector under the RH dash. Eliminates any "VATS" problems or misdiagnosis permanently.
EDIT: Where do the wires from that button under the ashtray go? That could be a "Ghost Switch". Ghost Switch systems are normally incorporated into an existing switch that needs to be manipulated after key=on to activate a circuit that allows the engine to crank or start. These devices are usually a relay array that latches upon activation, and resets when the key is turned off. If that button goes to a relay or relay array, figure out what car circuit the relay(s) are interfaced into.
Personally, I interface my ghost switch systems into the ECM "turn on" wire, usually a pink/blk. The indication to the driver of the ghost switch status is the Service Engine Soon light. If the key is on, but the SES is off, the ghost switch hasn't been activated. Something to know about. The "hidden button" used to do 'something'. If I was working on a car with the history and issues yours has, I'd want to know what that 'something' is/was. .
The Best of Corvette for Corvette Enthusiasts
What do you have for a cylinder now? A brass work key with a VATS cylinder or maybe a GM correct blank being used?
If a #1 bypass is used, might you still have issues? Maybe. IHBD's mention of the 'timers shop' eliminator is a very valid suggestion.
https://tunedperformance.org/store/p/gm-vats-delete





B: The timer.shop deal works. When you have it in hand report back, we can go over where to interface it to. IIRC the Fuel Enable signal wire in a 1986 is a different color than the dk blue of later years. WVZR has access to 1986 wiring schematics, I don't. Perhaps he will share with us the FE wire color.
C: Have Tuned performance remove VATS from your memcal. He's been on here and thirdgen.org for a long time. He knows what he's doing.
You will keep using the key and cylinder you have now. No reason to change it. The key and cyl under the dash will come out and go in the bin.
Last edited by IHBD; Mar 12, 2026 at 01:08 AM.













