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Discussion Starter #1
Hey guys
So my 62 coup with a 250 wasn’t running good so I decided to check the timing but the car won’t run or start with the vacuum advance disconnected. I did try advancing the time if to make up for no VA but it didn’t do anything.
Any ideas?
 

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Did you plug the vacuum hose. If you don't, you will create a huge vacuum leak, causing the car to run way too lean.
 

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Discussion Starter #4
I did plug it and it’s already idling at about 1000 and it doesn’t even start wouldn’t so wouldn’t that be the broblem if it died after starting
 

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Mike - 74 Nova Baltimore, MD
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What type of distributor are you using?... points?... electronic conversion?.... HEI?
If points.... did you check the dwell angle before attempting to adjust the timing?

Are you turning the distributor the correct direction to advance the timing?
You would turn the distributor counterclockwise to increase the timing.

What happens if you plug the vacuum advance hose back into the VA canister... will the engine start and run?
If so, disconnect the vacuum advance hose from the VA canister while the engine is running... but do not plug the VA hose. Does the engine still run?... did the rpms change any when you disconnected the VA hose (left unplugged)?
If the engine still ran with no change in RPM when you disconnected the VA hose, you might have a ruptured VA canister diaphragm that is leaking air (vacuum leak) and the carb idle mixture was adjusted using this extra air. When you disconnected and plugged the VA hose (eliminating extra air), the carb may now be too rich???
 

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Discussion Starter #7
What type of distributor are you using?... points?... electronic conversion?.... HEI?
If points.... did you check the dwell angle before attempting to adjust the timing?

Are you turning the distributor the correct direction to advance the timing?
You would turn the distributor counterclockwise to increase the timing.

What happens if you plug the vacuum advance hose back into the VA canister... will the engine start and run?
If so, disconnect the vacuum advance hose from the VA canister while the engine is running... but do not plug the VA hose. Does the engine still run?... did the rpms change any when you disconnected the VA hose (left unplugged)?
If the engine still ran with no change in RPM when you disconnected the VA hose, you might have a ruptured VA canister diaphragm that is leaking air (vacuum leak) and the carb idle mixture was adjusted using this extra air. When you disconnected and plugged the VA hose (eliminating extra air), the carb may now be too rich???
So it is points I have not checked the dwell. yes I was turning it counter clockwise. If I start it with VA connected the seacond I disconnect the VA it instantly dies
 

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I would pull the cap. I'd guess (as stated above) that the signal wire to the points is getting grounded. Of course, you would think it would also stall at WOT. Do you have a spark tester? I would try that. If you don't have one, they are cheap and available at any auto parts store or even some hardware stores. I would also try just pinching the hose with vice grips or pliers vs. disconnecting the hose. That eliminates the vacuum leak factor.
 

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Mike - 74 Nova Baltimore, MD
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If I start it with VA connected, the second I disconnect the VA it instantly dies
Engine dies instantly... is it the same as if you turned the ignition key off?

If so, I agree with drm101 and Pmotion that there may be a bad connection in the distributor that interrupts the ignition circuit when the breaker plate moves when VA is disconnected. Remove the cap and inspect wires and connections.
Be sure to also check for any unusual play in the distributor shaft and/or breaker plate.

While the distributor cap is removed, disconnect the coil wire from the coil and remove the rotor.
Bump start... or rotate your engine until the rubbing block of the points is resting on the top portion of a distributor cam lobe (red arrow) and confirm that the points are open (red circle). Check the point gap and adjust as needed.
411083
 

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Discussion Starter #10
Ok so today I took the cap off and tried to adjust the points but the rubbing block was worn down to where I could not adjust it enough to get any gap at the points. Got new points and now everything thing is running great thanks everyone for the help!
 

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Mike - 74 Nova Baltimore, MD
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Glad to hear that you found the issue.

If you have a dwell meter, you might want to check the dwell of the new points with the VA connected.... and then with the VA disconnected. If there is a change in the dwell between the two tests, it might indicate some wear/play on the distributor's breaker plate assembly. The VA arm might be pulling the breaker plate closer to the distributor cam when the VA is engaged. That might explain why the engine would run with VA connected... and then immediately die when the VA was disconnected (when the engine had the old points).
 
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