The Ford Barn

whatdoyouwant · 06-27-2025, 12:19 PM

My 272 coughs and sputters while accelerating in first and second. It runs fine in third and overdrive because of lower RPM. I checked the vacuum at idle and it is between 15 and 16 and the needle shakes. This is at 500 RPM. By turning the carb air screws, I can lower the vacuum but never raise it any. I have taken the hose that runs from the dual acting fuel pump to inside the car and plugged it with no change. So I don't think I have a leak it the vacuum hoses. This has done this for years and I changed to electronic ignition with no change.
any thoughts would be welcome.

Gene F · 06-27-2025, 12:34 PM

Is the carb loose?

KULTULZ · 06-27-2025, 01:59 PM

GO HERE - https://www.onallcylinders.com/2016/...auge-readings/

whatdoyouwant · 06-27-2025, 03:15 PM

Thanks KULTULZ, the readings should be real helpful. Another link on that page said these readings are at sea level, and for each 1000 feet above the reading will drop one inch. I am at 6000 feet, but still wonder if I have late timing. Have you experienced this with late timing?

KULTULZ · 06-27-2025, 03:24 PM

Sponsored Links (Register now to hide all advertisements)

In regards to IGN TIMING, you have a LOAD-O-MATIC SYSTEM and proper initial timing and advance needs to be determined (and corrected).

- https://www.classiccarrestorationclu...oubleshooting/

- https://www.motor.com/magazinepdfs/082001_05.pdf

The VACUUM GAUGE should point you in the direction of the problem(s).

06-27-2025, 12:19 PM	#1
whatdoyouwant Senior Member Join Date: Jan 2022 Posts: 165	1955 ford 272 My 272 coughs and sputters while accelerating in first and second. It runs fine in third and overdrive because of lower RPM. I checked the vacuum at idle and it is between 15 and 16 and the needle shakes. This is at 500 RPM. By turning the carb air screws, I can lower the vacuum but never raise it any. I have taken the hose that runs from the dual acting fuel pump to inside the car and plugged it with no change. So I don't think I have a leak it the vacuum hoses. This has done this for years and I changed to electronic ignition with no change. any thoughts would be welcome.

06-27-2025, 12:34 PM	#2
Gene F Senior Member Join Date: Mar 2012 Location: Ohio Posts: 2,476	Re: 1955 ford 272 Is the carb loose?

06-27-2025, 01:59 PM	#3
KULTULZ Senior Member Join Date: Aug 2012 Location: IN A GALAXIE FAR, FAR AWAY Posts: 7,386	Re: 1955 ford 272 GO HERE - https://www.onallcylinders.com/2016/...auge-readings/

06-27-2025, 03:15 PM	#4
whatdoyouwant Senior Member Join Date: Jan 2022 Posts: 165	Re: 1955 ford 272 Thanks KULTULZ, the readings should be real helpful. Another link on that page said these readings are at sea level, and for each 1000 feet above the reading will drop one inch. I am at 6000 feet, but still wonder if I have late timing. Have you experienced this with late timing?

06-27-2025, 03:24 PM	#5
KULTULZ Senior Member Join Date: Aug 2012 Location: IN A GALAXIE FAR, FAR AWAY Posts: 7,386	Re: 1955 ford 272 Sponsored Links (Register now to hide all advertisements) In regards to IGN TIMING, you have a LOAD-O-MATIC SYSTEM and proper initial timing and advance needs to be determined (and corrected). - https://www.classiccarrestorationclu...oubleshooting/ - https://www.motor.com/magazinepdfs/082001_05.pdf The VACUUM GAUGE should point you in the direction of the problem(s). __________________ ***** "Last Sunday, I caught him makin' eyes at Idell Bushey durin' preachin'. And I know what they do up there in the hills when they say they're possum huntin'. They're just sittin' around the campfire, drinkin' hard cider, hittin' each other on the shoulder and hollerin' 'flinch!'." ― Charlene Darling (Daughter of Briscoe Darling)