Hello.
1966 F100 352FE, manual choke, Holley 4412 2bbl carb, 2wd, 3 spd. I've been having drivability issues lately, since the weather turned really cold.
Started with stuttering at mid throttle. At idle, off idle or full throttle it ran OK.
I have checked and adjusted air fuel mixtures up and down, adjusted float level up and down, replaced accelerator pump diaphragm, adjusted accelerator pump arm, replaced carb base gasket, checked and rechecked timing, advancing and retarding. Pulled and reinstalled distributor, moving 1 tooth forward as well as 1 tooth backwards. Replaced timing chain and gears.
Base timing is about 8-10 degrees. with high RPM the timing marks advance to, what I believe to be 30 degrees or the last mark on the balancer.
Checked spark plugs, they look like firing correctly. Not fouled or lean. Checked ported vacuum on carb.,where vacuum advance is connected, no vacuum at idle.
I replaced the vacuum advance, the points, and plugs in July.
The other night I found it would not run with the vacuum advance hose connected. I pulled the hose and plugged it so no vacuum leak. It ran much better. Left it that way and drove to work past few days.
Pulled the vacuum advance completely off the distributor to test it again, it does move when I sucked on it.
Tried driving with vacuum advance completely removed, ran terrible, spit and sputtered unable to build any road speed.
Put vacuum advance back on, but did not connect hose, ran ok.
Connected the vacuum hose, will not run.
Disconnected hose and plugged drove home fine.
Drove to work today with vacuum advance on, hose disconnected and plugged, morning ran fine, afternoon back to spitting and sputtering, no road speed.
Pulled over, tried connecting vacuum hose, this time it would idle with hose connected but wanted to die with any throttle.
Disconnected the hose and plugged it and it ran fine again and drove home. I suspect carb and distributor issues?
Yesterday just purchased a Autolite 2100 2bbl on Marketplace, still need to get it rebuilt.
What would cause engine to die when vacuum advance hose is connected.
I have driven since July with the vacuum advance hose connected to ported vacuum, until 5 days ago when this all started.
Just not sure what direction to go. Any help would be great. Thanks.

 

You need to find yourself a mechanic. Totally removing the vacuum advance canister will and apparently did allow the breaker plate to move anywhere it felt like going. Resulting in uncontrolled timing input.
Your shop manual will tell you how the original distributor was calibrated. In order to check a distributor and vacuum canister on a running engine you need a dial back timing light and a handheld vacuum pump. The vacuum advance would have been connected to full vacuum on the original carburetor. Ported vacuum is an exhaust emission thing.

 

Thank you.

 

FORD went to ported vacuum in 1957 (after LOAD-O-MATIC) and continued to 1968 with the intro of IMCO where it would use a combination of ported and manifold vacuum.

The engine should still run without a vacuum signal (not as well) as there is still mechanical advance if the breaker plates are not frozen. You need to watch the damper timing marks with a timing light while accelerating the engine with and without the vacuum signal applied for proper advance.

If hooked to manifold vacuum, it will give full advance at idle. That is a GM thing. If you decide to go that route the DIST needs to be re-calibrated..

 

If hooked to manifold vacuum, it will give full advance at idle. That is a GM thing. If you decide to go that route the DIST needs to be re-calibrated..

Not true! This is an original 65 carb it is essentially the same as a 66 and is what his truck would have come with. As you can see the vacuum port is below the throttle blades. (Full manifold Vacuum). There are no other vacuum ports on these carburetors. The only reason to connect a distributor vacuum can to ported vacuum is if you have to pass a tailpipe sniffer test.

 

!!! DAMN !!!
Must be RED LETTER DAY ...

NO CAPS?

How do you come to this conclusion. I started at my first FORD DEALER in 1966 and I don't ever remember seeing a DUAL ADVANCE DIST that had MANIFOLD VACUUM as it's primary signal source.

 

Well, all I can is the critters used full manifold vacuum since that was all that was on the carburetor, and the distributor was a hard lined to it. Get out your 66-shop manual and take a look.

 

Check the distributor for slop. I had timing that was jumping around, and a reman distributor fixed the issue. Get a good diagnosis before throwing parts at the problem.

 

... and make sure the DIST ADVANCE CANISTER holds a vacuum.