351c, 2v. The vacumn advance runs off a tree valve (don't know the real name for it) on the thermostat housing. There is no, or little vacumn at idle but on acceleration vacumn rises. The car has a stumble just off idle, you know the one, where you break your nose on the steering wheel and then get whip lash when it catches. It appears that there is instant vacumn on acceleration, but if it is not here at idle could this be the cause of the stumble? TIA, Tbolt

The dizzy is connected to ported vacuum then. This is how I connect the dizzy on my cars, and they have no stumble.

If you have a stumble it isn't caused by teh vacuum advance. Look elsewhere like the carb. Hawkrod

Hawkrod

39 Ford Deluxe Coupe
59 Tbird 430
60 Lincoln Premier
(2)62 Tbirds
(3)68 Cougar XR7-G's
69 Cougar 428CJ 4 speed
77 1/2 Ford F250 4X4 w/460 swap
86 SVO mustang
76 F250 Crew Cab
1969 Mach I
look at my cars past and present at superford!

Power valve or squirters if a Holley. Otherwise just the squirter circut. Make sure it shoots fuel right off the bat.

Yep, can cause a big stumble. I remember being at Bakersfield racing my Mustang and Pete Pestere (sp) was there racing a Mustang in the same class. He had a terrible bog off the line and couldn't find the problem. I looked down his carb and saw that he had no pump shot when he hit the gas. I took the float bowl off his Holley and found he had the gaskets in backward. The hole for the squirter was blocked by the gaskets.
Funny thing was he was editor of FF magazine at the time.


Mike G

being you have a two barrel carb and it is a 2100 or 2150 autolite or ford as we called them,check the accelerator pump to be sure it squirts as soon as you move the throttle.if not,move it a time or two and if it squirts as soon as you move it then the check ball in the booster area is not seating and holding gas in it.You can take the top off and remove the boosters,take a 1/8" flat punch and tap the ball a few times.It will help make a better seat for the ball.The casting in them sometime causes them to not hold the gas.You can also check the pump diph by removing it to see if the red rubber check valve in it is still good.Those carbs are very easy to put anew kit in.Even for a novice.

a temp controlled valve.The bottom port of the three has manifold vacuum so when the engine gets too hot,it switches to give the dist full manifold vacuum to help cool it down

I checked the accelerator pump before posting. After the replys I rechecked it and it appears to be working correctly. I had rebuilt the carb a few months ago and have not had time to fine tune anything until now. I just wasn't sure if I didn't have vacumn quick enough. The car runs good other than this. Any other ideas? Thanks again, Tbolt