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74 260z with 280zx matchbox dizzy - do i need the vacuum advance??

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apparently the vacuum advance does not work on the 280zx matchbox dizzy i just put in my 260.. is that ok? i have been told car will run fine without it and some guys dont even hook it up... when sucking on hose nothing happens - when the mechanic did that..  what will effects be without it? can i change the vacuum advance ? can i fix it??


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Pull the cap off so you can see the advance if it happens. Pull the vacuum advance hose of the carburetor and make sure no cracks that leak. Suck on the end and the breaker plate should turn clockwise approx. 1/2". Hold the suction and the plate should remain fixed till you let go. Vacuum advance is presumed good.



Vacuum advance...

The throttle plate regulates just how much gas and air can get into the cylinder. Idle and part throttle mean the cylinder is not nearly filled with gas and air molecules and even when compressed and lit it takes much longer for the flame to travel across the combustion chamber and burn everything than if the throttle is wide open and the cylinder filled and tightly packed. A weakly filled cylinder needs more time to burn completely so the distributor has to send the spark sooner or advanced and this is what the vacuum advance does. Without it the spark arrives too late and the fuel/air doesn't have enough time to burn and it's potential power is wasted. Your throttle response, mileage and efficiency is better with vacuum advance.... but only at part throttle... where most of your driving is. 


Can you run without it, sure, no harm done, you're just not getting everything out of your gas.

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