Dual Vacuum Advance Problem? Hesitation?

[palerider94]

I've been trying to hunt down an hestiation problem since I installed new intake gaskets. No hesitation at all until then - new carb, fuel lines, etc.

Based on some other posts I thought it may be related to the vacuum advance on the dizzy - ive got dual vacuum hoses on mine. One goes to the full vaccum port on the bottom of the carb the other on the right hand side port (opposite of throttle linkage).

I thought I may had both hoses reversed causing hesitation but made no difference when switching around. Matter of fact it made no difference when taking off carb completely other than it idled higher.

I hooked one hose to bottom and checked vacuum on the other and nothing -tried switching around same result.

Is this how it is suppose to be or am I'm on to something related to hesitation problem. Any advice appreciated. thanks

Car is 70, 302 with 600 holley, and performer 289 edelbrock with ignitor igntion.

 

[zookeeper]

If it were me, I'd get rid of the dual diaphragm cannister and swap in a simpler, more reliable single canister unit. Originally both of the hoses from your dual canister should have gone to a two-ported, temperature-controlled "switch" located at the front of your manifold. If not, then someone, somewhere decided to simply plug them into two vacant vacuum ports. If your car still has the original manifold, look for the dual port switch near the thermostat and remove it and plug it with a pipe plug. Then go to pretty much any parts store and tell them you need a single diaphragm canister for a small block Ford. When you install the single unit, connect the vacuum line into the ported vacuum port on the passenger side of the metering block of your Holley. I'll bet your problem goes away after that.