‘68 wont shut off with key
Thread Starter
Drifting
Joined: Jul 2020
Posts: 1,501
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From: San Diego
‘68 wont shut off with key
I just installed a 383 Stroker motor with an MSD ignition and the car starts just fine but when I turn the key off nothing happens. I checked voltage at the coil with the key off but doesnt seem like I get any. I also checked the keyed hot wires and the seem to be always hot not just keyed hot.
Im not sure where else to look. I disconnected the battery while the car was running and that didnt shut it off ao I put it in fourth and stalled it. Any ideas cause I dont want to keep doing that.
Im not sure where else to look. I disconnected the battery while the car was running and that didnt shut it off ao I put it in fourth and stalled it. Any ideas cause I dont want to keep doing that.
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Bad diode in Alternator. try unhooking Alternator temporarily, start engine and see if it shuts down with Alternator disconnected.
Race Director
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From: Virginia
Was the engine broken in by the builder, or is that your problem too? Do you need to time it, and is there any chance that your timing is WAY off, and this is run-on/dieseling?
Most likely, this is a simple wiring issue of the MSD box.
You can also stop the engine by smothering the carb. Just don't let stuff get sucked in.
Post some pictures!
Most likely, this is a simple wiring issue of the MSD box.
You can also stop the engine by smothering the carb. Just don't let stuff get sucked in.
Post some pictures!
Thread Starter
Drifting
Joined: Jul 2020
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From: San Diego
The was put on a run stand and completely broken in, timing is set and it starts and runs perfect but it wont shut off.
Actually, last night it shut off one time with the key and that was it. Could the ignition be bad? Do they fail?
I dont think its the alternator because it is brand new.
I did a complete build thread from pulling the engine to it finally running here:
https://www.corvetteforum.com/forums...h-5-speed.html
Actually, last night it shut off one time with the key and that was it. Could the ignition be bad? Do they fail?
I dont think its the alternator because it is brand new.
I did a complete build thread from pulling the engine to it finally running here:
https://www.corvetteforum.com/forums...h-5-speed.html
Is my vette stock?? HAHA
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What is your power source to your MSD. I would guess that you have it powered striaght from some source that is always on and not keyed to an ignition source. A regular 68 coil has 2 power sources, yellow and white, 1 that is on with the key in the on positions and the other comes from the starter solenoid and provide power during cranking position
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From: Virginia
I didn't see it when I skimmed your build thread.
Are you 100% sure it is not dieseling? That would seem like a stumble. Have you checked the temperature of the upper radiator hose with an IR thermometer? Is your vacuum advance connected to manifold vacuum?
Are you 100% sure it is not dieseling? That would seem like a stumble. Have you checked the temperature of the upper radiator hose with an IR thermometer? Is your vacuum advance connected to manifold vacuum?
Last edited by Bikespace; Oct 3, 2021 at 08:58 PM.
Thread Starter
Drifting
Joined: Jul 2020
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From: San Diego
So because the engine turns off at the switch from time to time, I tend to think my trouble is with my ignition switch. Im going to pull it and check it out.
Is there anyone who rebuilds ignition switches? My key currently works my ignition and my doors so I like them all keyed the same. If I swap the ignition switch then my keys wont match.
Is there anyone who rebuilds ignition switches? My key currently works my ignition and my doors so I like them all keyed the same. If I swap the ignition switch then my keys wont match.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
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If you do need a new one you should be able to swap out the cores or have the doors re-keyed to match the new ignition switch
Thread Starter
Drifting
Joined: Jul 2020
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From: San Diego
So now the last few times I have turned the key off it has been working. Im not sure what happened but its as if it fixed itself. Do the ignition switches work better the more they are used?
Le Mans Master
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*** NEVERMIND*** I see in your other post that you have a mini starter. I'll leave the info below in case it is helpful to someone else.
Just FYI. I had that same intermittent problem and also an intermittent battery drain. It took me a while to find. Turned out to be the stock starter solenoid had and internal intermittent fault--- I found it by wiggling the wiring to the starter while monitoring for amperage draw across the negative to negative lead. May be a long shot, but if you have a stock starter it may be worth a check.
Just FYI. I had that same intermittent problem and also an intermittent battery drain. It took me a while to find. Turned out to be the stock starter solenoid had and internal intermittent fault--- I found it by wiggling the wiring to the starter while monitoring for amperage draw across the negative to negative lead. May be a long shot, but if you have a stock starter it may be worth a check.
Last edited by carriljc; Oct 7, 2021 at 02:12 PM.