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 06-08-2016, 05:35 PM   #1
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Unhappy 30 Zenith Carb

My 30 appears to have a carb problem. Idles great but put it under load and it starts coughing back through the carb. Forum member and I think it is acting like a float problem. Has good fuel flow. No starting probs, no overheating issues. Tried numerous GAV settings all to no avail. I have read that a sticky/hung float can exhibit symptoms like this. Now to the point I could not make it 1/8th of a mile back to the driveway this morning . Thanks
William Kelchner is offline   Reply With Quote
Old 06-08-2016, 05:59 PM   #2
700rpm
Senior Member
 
700rpm's Avatar
 
Join Date: May 2010
Location: Portland, Oregon
Posts: 5,892
Default Re: 30 Zenith Carb

If this just started, I would suspect it's not the carb. My first thought is condenser.
__________________
Ray Horton, Portland, OR


As you go through life, keep your eye on the donut, not the hole.
700rpm is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-08-2016, 06:01 PM   #3
Mitch//pa
BANNED
 
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
Default Re: 30 Zenith Carb

Are the points gapped ok
Mitch//pa is offline   Reply With Quote
Old 06-08-2016, 08:28 PM   #4
kenparker
Senior Member
 
kenparker's Avatar
 
Join Date: May 2010
Location: Van, Texas
Posts: 1,122
Default Re: 30 Zenith Carb

In the model A world 85% of the carburetor problems are electrically generated.
kenparker is offline   Reply With Quote
Old 06-09-2016, 11:46 AM   #5
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Smile Re: 30 Zenith Carb

Quote:
Originally Posted by kenparker View Post
In the model A world 85% of the carburetor problems are electrically generated.
Yep it is a constant problem and prevents me from even attempting to venture out with the car. Love the quote. One thing that stumps me is the car will idle great, rev the he$$ out of it and it is flawless, but don't try to drive it. Oh well - thanks for the responses. Have a good weekend.
William Kelchner is offline   Reply With Quote
Old 06-09-2016, 12:57 PM   #6
txkhog
Member
 
Join Date: Nov 2015
Location: Texarkana, TX
Posts: 61
Default Re: 30 Zenith Carb

Sponsored Links (Register now to hide all advertisements)
also check your coils, plugs inside cap. when there is a load on the engine it takes more spark energy to fire the plug and the spark may be finding an easier path to ground than across the plug gap.
txkhog is offline   Reply With Quote
Old 06-09-2016, 01:04 PM   #7
mrraford
Senior Member
 
Join Date: Jul 2012
Posts: 190
Default Re: 30 Zenith Carb

Couple of thoughts here:
you may want to check to make sure the jets are not clogged in the carb.
condenser could be the answer.
is it timed correctly? Is the timing advance working properly?
make sure your distributor and coil are working properly. ie point gap, timing setting, good coil, good condenser.
We would like to hear the ultimate answer here. Please report back.
mrraford is offline   Reply With Quote
Old 06-09-2016, 01:20 PM   #8
30ccpickup
Senior Member
 
30ccpickup's Avatar
 
Join Date: May 2010
Location: Wakarusa, IN
Posts: 928
Default Re: 30 Zenith Carb

Backfiring Under Load (throttle wide open at relatively low rpm’s) often indicates a problem in electrical/ignition/timing.

Culprits include:

Insufficient point gap (should be set at .018 to .020)
Timing
Bad condenser
Bad distributor body
Frayed wire between upper plate and lower plate on the distributor
Intermittent connection of the ignition switch

As Mitch said I, would start with point gap.
__________________
http://MODELABASICS.com/ How Things Work on a Model "A" Ford

Fordbarners, Feel free to use the pictures on my site to answer questions and create tutorials/tech articles.
30ccpickup is offline   Reply With Quote
Old 06-09-2016, 02:11 PM   #9
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Default Re: 30 Zenith Carb

Ok you guys thanks. I shall go through everything over the weekend, saving the carb for last, hopefully the culprit will be identified. I replaced the dist with an original type from Bratton's, the Zenith was also purchased from them, all this about 2 years ago. I also replaced the timing gear around that time.

I shall report back. Thanks again.
William Kelchner is offline   Reply With Quote
Old 06-09-2016, 06:30 PM   #10
diomed
Senior Member
 
diomed's Avatar
 
Join Date: May 2012
Location: Las Vegas
Posts: 138
Default Re: 30 Zenith Carb

I've heard of this happening with bad muffler. A baffle collapses inside and restricts the exhaust flow. It'll start and rev in neutral just fine. Once you put it under a load it has no power. It's very rare but sometimes it happens.

Quote:
Originally Posted by William Kelchner View Post
...One thing that stumps me is the car will idle great, rev the he$$ out of it and it is flawless, but don't try to drive it. Oh well - thanks for the responses. Have a good weekend.
__________________
kris
diomed is offline   Reply With Quote
Old 06-09-2016, 09:37 PM   #11
Quigley1930
Senior Member
 
Quigley1930's Avatar
 
Join Date: Jun 2010
Location: Middleburg, Virginia
Posts: 421
Default Re: 30 Zenith Carb

Bill, I'll meet you in Marshall at the Ford dealer and we will get 'er done

Sewall
Quigley1930 is offline   Reply With Quote
Old 06-10-2016, 08:59 AM   #12
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Default Re: 30 Zenith Carb

Thanks Quigly, I can always count on you
William Kelchner is offline   Reply With Quote
Old 06-11-2016, 03:51 PM   #13
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Smile Re: 30 Zenith Carb

Well installed new points (orig style), the others did not look well and seen better days. Re-timed, checked spark (Tesla would be proud) Tried to make it around the block, almost made it but coughed several times. Carb tomorrow, another trip around the block. If no better there will be a lot more room in the garage. Have a good weekend.....

Bill K
William Kelchner is offline   Reply With Quote
Old 06-11-2016, 07:19 PM   #14
Tom Wesenberg
Senior Member
 
Tom Wesenberg's Avatar
 
Join Date: May 2010
Location: Mpls, MN
Posts: 27,582
Default Re: 30 Zenith Carb

Never give up..................it's such a good feeling when you find the problem.
Tom Wesenberg is offline   Reply With Quote
Old 06-11-2016, 08:01 PM   #15
700rpm
Senior Member
 
700rpm's Avatar
 
Join Date: May 2010
Location: Portland, Oregon
Posts: 5,892
Default Re: 30 Zenith Carb

Condenser.
__________________
Ray Horton, Portland, OR


As you go through life, keep your eye on the donut, not the hole.
700rpm is offline   Reply With Quote
Old 06-12-2016, 08:10 AM   #16
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Default Re: 30 Zenith Carb

Quote:
Originally Posted by 700rpm View Post
Condenser.
I have a "burn-out Proof" condenser, so the catalogue said. I replaced my dist several years ago with a rebuilt one from Brattons, it had the cap installed. Tnx
William Kelchner is offline   Reply With Quote
Old 06-12-2016, 09:47 AM   #17
Art Newland
Senior Member
 
Art Newland's Avatar
 
Join Date: Mar 2016
Location: Lynden, WA
Posts: 1,564
Default Re: 30 Zenith Carb

Are you sure the fuel flow is OK? Too lean a fuel mixture for what ever reason can cause low power/backfiring. I took a very short video of my fuel flow after flushing my fuel tank and adding a new filter screen above the shut-off valve. I thought it was OK too, at first. Once I started getting it running better and producing more power it wasn't getting enough fuel.
https://www.youtube.com/watch?v=FAUI8MWo_Io
Art Newland is offline   Reply With Quote
Old 06-12-2016, 03:43 PM   #18
William Kelchner
Senior Member
 
William Kelchner's Avatar
 
Join Date: Feb 2012
Location: Warrenton, Va.
Posts: 459
Default Re: 30 Zenith Carb

Thanks Art. Yep my fuel flow is robust, disassembled the Zenith today, clean as a whistle, blew everything anyway. Did not go for a ride as it is in the high 90's. I plan a compression test tomorrow and that will do it, told the wife to cancel her Father's Day gift order (car cover for the A)..... Cheers and thanks for all the suggestions.
William Kelchner is offline   Reply With Quote
Old 06-12-2016, 04:30 PM   #19
30ccpickup
Senior Member
 
30ccpickup's Avatar
 
Join Date: May 2010
Location: Wakarusa, IN
Posts: 928
Default Re: 30 Zenith Carb

Devorce is to easy, she is testing you. There is nothing in the relationship that cannot be overcome, it just takes work and understanding. I love my mother's favorite quote, "it is easy once known". You have a simple problem that can be overcome, it will only happen once because next time you will know the answer. Be patient work it through, except the challenge.
__________________
http://MODELABASICS.com/ How Things Work on a Model "A" Ford

Fordbarners, Feel free to use the pictures on my site to answer questions and create tutorials/tech articles.
30ccpickup is offline   Reply With Quote
Old 06-12-2016, 04:34 PM   #20
Mitch//pa
BANNED
 
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
Default Re: 30 Zenith Carb

What happened to Quigley's offer of help?
Mitch//pa 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 03:40 PM.