Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 01-24-2021, 12:09 PM   #1
Ayers1
Senior Member
 
Ayers1's Avatar
 
Join Date: Jan 2021
Location: Waynesboro Va.
Posts: 205
Default Popping carb

Hi all, I have a 1930 Tudor sedan that I am ready to put back on the road. It hasn't been driven since 1970. The motor, engine and drive train was supposedly all rebuilt in the 70's when the previous owner started the restoration. I have tried driving it a time or 2 but it wants to pop back through the carburetor when you give it gas. I have done the following and am at a loss on what to look at next. Rebuilt carb and distributor, replaced coil, checked and replaced cracked head, had 4 valves that did not have enough clearance so I fixed that. Went back in and replaced the valves, guides, and springs. Thought there may have been a weak point there. The popping is more prevalent the hotter the engine gets. It idles great, just won't run on the road. Any ideas are greatly appreciated!
Ayers1 is offline   Reply With Quote
Old 01-24-2021, 12:12 PM   #2
Jack Shaft
BANNED
 
Join Date: Dec 2019
Posts: 1,196
Default Re: Popping carb

check the timing gear.
Jack Shaft is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 01-24-2021, 12:24 PM   #3
frank mcdaniels
Senior Member
 
frank mcdaniels's Avatar
 
Join Date: May 2010
Location: moorhead minnesota
Posts: 166
Default Re: Popping carb

Ayers 1. Welcome to the barn. The times I’ve had this problem I have found it to be a vacuum leak somewhere in the intake system. Make sure the connection between the carb and intake manifold is nice and tight. Also make sure there are no leaks in the manifold itself The engine will pop from getting to much air. Hope this helps. Good luck. Frank
frank mcdaniels is offline   Reply With Quote
Old 01-24-2021, 01:20 PM   #4
Ayers1
Senior Member
 
Ayers1's Avatar
 
Join Date: Jan 2021
Location: Waynesboro Va.
Posts: 205
Default Re: Popping carb

Thanks for bringing that up. I have also replaced the intake and exhaust manifolds as the old ones were warped. New gaskets and all but I'll check it out.
Ayers1 is offline   Reply With Quote
Old 01-24-2021, 01:24 PM   #5
Ayers1
Senior Member
 
Ayers1's Avatar
 
Join Date: Jan 2021
Location: Waynesboro Va.
Posts: 205
Default Re: Popping carb

Thanks Jack, since it's been almost 50 years since the engine was apart you think the fiber timing gear could be soft and moving?
Ayers1 is offline   Reply With Quote
Old 01-24-2021, 12:26 PM   #6
Chuck Dempsey
Senior Member
 
Chuck Dempsey's Avatar
 
Join Date: May 2010
Location: Waynesville, NC
Posts: 778
Default Re: Popping carb

Sponsored Links (Register now to hide all advertisements)
Yes, welcome to the Barn....
Chuck Dempsey is offline   Reply With Quote
Old 01-24-2021, 04:35 PM   #7
Fred K OR
Member
 
Join Date: Nov 2019
Posts: 45
Default Re: Popping carb

You may open up the gas valve to the card. May be starved for gas.
Fred K OR is offline   Reply With Quote
Old 01-24-2021, 04:46 PM   #8
Mulletwagon
Senior Member
 
Mulletwagon's Avatar
 
Join Date: Jan 2019
Location: Florida Panhandle
Posts: 585
Default Re: Popping carb

How is the valve lash ? One valve too tight could cause the condition.
Mulletwagon is offline   Reply With Quote
Old 01-24-2021, 05:43 PM   #9
Ruth
Senior Member
 
Join Date: May 2016
Location: Glide, Oregon
Posts: 1,334
Default Re: Popping carb

Quote:
Originally Posted by Ayers1 View Post
Hi all, I have a 1930 Tudor sedan that I am ready to put back on the road. It hasn't been driven since 1970. The motor, engine and drive train was supposedly all rebuilt in the 70's when the previous owner started the restoration. I have tried driving it a time or 2 but it wants to pop back through the carburetor when you give it gas. I have done the following and am at a loss on what to look at next. Rebuilt carb and distributor, replaced coil, checked and replaced cracked head, had 4 valves that did not have enough clearance so I fixed that. Went back in and replaced the valves, guides, and springs. Thought there may have been a weak point there. The popping is more prevalent the hotter the engine gets. It idles great, just won't run on the road. Any ideas are greatly appreciated!
Quote:
Originally Posted by Mulletwagon View Post
How is the valve lash ? One valve too tight could cause the condition.
See post #1.
__________________
Ruth
"Sometimes you really DO need to read the whole thread"
Ruth is offline   Reply With Quote
Old 01-24-2021, 06:44 PM   #10
Jerry in Shasta
Senior Member
 
Jerry in Shasta's Avatar
 
Join Date: Jun 2010
Location: (Old)Shasta (Redding) CA
Posts: 385
Default Re: Popping carb

Try a couple of squirts a Marval Mistery oil in to the carb. while she's running sounds like maybe a sticky valve
__________________
Connoisseur of Rust
Jerry in Shasta is offline   Reply With Quote
Old 01-24-2021, 07:24 PM   #11
Ayers1
Senior Member
 
Ayers1's Avatar
 
Join Date: Jan 2021
Location: Waynesboro Va.
Posts: 205
Default Re: Popping carb

Thanks for everyone's suggestions. As soon as it gets warm enough I'll go out in the garage and try again. Since I had put a new manifold set on I didn't think about a vacuum leak. I'll start there and see where it leads me. I'll post as soon as I try a couple of things.
Ayers1 is offline   Reply With Quote
Old 01-24-2021, 07:33 PM   #12
Herb Concord Ca
Senior Member
 
Join Date: May 2010
Location: Concord CA
Posts: 623
Default Re: Popping carb

Did you check for flatness on the new manifold set? Put a straight edge across the 4 ports, you should have no gaps.
Herb Concord Ca is offline   Reply With Quote
Old 01-24-2021, 08:23 PM   #13
01A
Junior Member
 
01A's Avatar
 
Join Date: Apr 2015
Location: Aston, Pa
Posts: 13
Default Re: Popping carb

I'm not sure if your 30 Tudor has a vacuum windshield wiper like my 29 Tudor does but if it does check the condition of the rubber tubing that runs on the outside of the windshield between the metal tubeing connection and the wiper body. If cracked it will change the air intake to the carb.
01A is offline   Reply With Quote
Old 01-24-2021, 08:40 PM   #14
Ayers1
Senior Member
 
Ayers1's Avatar
 
Join Date: Jan 2021
Location: Waynesboro Va.
Posts: 205
Default Re: Popping carb

I didn't think to check the flatness of the new set. I assumed they would be right. We know what assuming does for ya!

Mine does have the vacuum wiper. I had it professionally rebuilt before I put it on. Now that I have been pointed in the direction of a leak, I may have to go back and check it again.
Ayers1 is offline   Reply With Quote
Old 01-25-2021, 08:54 AM   #15
old31
Senior Member
 
Join Date: Jan 2016
Posts: 2,088
Default Re: Popping carb

Ayers, welcome to the forum.

If you have about a full tank then put in about 4 oz of Mystery Marvell oil in the tank.

Check your vacuum line from the intake all the way to the wiper to make sure the hose does not have any holes or cracks.

On the road, try opening up the GAV 2-3 turns and see if that makes a difference. To me, it sounds more like a carb issue.
old31 is offline   Reply With Quote
Old 01-25-2021, 08:56 AM   #16
ronn
Senior Member
 
Join Date: Feb 2011
Location: NNNNNNNNJJJJJJJJJJ
Posts: 6,758
Default Re: Popping carb

My carb did the same- sticking float..........


MMO and all quieted down.
ronn is offline   Reply With Quote
Old 01-26-2021, 05:42 PM   #17
Ayers1
Senior Member
 
Ayers1's Avatar
 
Join Date: Jan 2021
Location: Waynesboro Va.
Posts: 205
Smile Re: Popping carb

Thanks for the additional suggestions! I'll try the Marvel Mystery oil and see how that goes. Hopefully I'll get a chance to work with it tomorrow and get something figured out!
Ayers1 is offline   Reply With Quote
Old 01-27-2021, 08:21 AM   #18
eagle
Senior Member
 
eagle's Avatar
 
Join Date: Aug 2011
Location: Eagle Bend, MN
Posts: 2,025
Default Re: Popping carb

To check for manifold gasket leak, use a LP gas torch, unlit, and direct the gas around the gasket area while the engine is idling. RPM change will tell you about a leak. However, any gas getting sucked inyo the intake will also affect it so be careful to keep it away from there.
__________________
"There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."
eagle is offline   Reply With Quote
Old 01-27-2021, 10:26 AM   #19
duffy
Junior Member
 
Join Date: Oct 2020
Posts: 9
Default Re: Popping carb

Try opening AGV further. Works everytime for me. This is the under dash gas adjusting valve.
duffy is offline   Reply With Quote
Old 01-27-2021, 04:11 PM   #20
Dick M
Senior Member
 
Dick M's Avatar
 
Join Date: May 2010
Location: Ukiah, CA
Posts: 477
Send a message via Yahoo to Dick M
Default Re: Popping carb

I agree with the suggestions on this thread. However, a restricted gas flow will cause your engine to pop.
Things to check:
Disconnect the gas line at the carb and see if you have good flow from the gas tank.
If not a good flow, check to see that the ferrule on each end of the gas line is very close to the end of the gas line. You will have a restriction if the gas line is too far into the filter bowl or carb.
Dick M is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:06 PM.