The Ford Barn

Andy0011 · 11-04-2019, 07:49 PM

Hello everyone! I am new here and I am from Argentina. I don't speak english very well, sorry if I have mistakes!
My question for the forum is that I recently revived my 29 town sedan that was sleeping for more than 6 years because it did not started. I cleaned the plugs, and I disamble the zenith carb, cleaned it and it came back to life.
But I noticed that have a problem with the GAV. It acts very sensitive. If I open 1 turn to the left it sounds as if it too rich, if I try to find the 1/4 turn open the idle sounds ok to me, but if I close it just a little bit from there it begins to be irregular, and if I completely close it, the car dies.
I think that it should not happen, it should be running if it is closed, so I need some help with the possible diagnosis.
Thanks!!!

aermotor · 11-04-2019, 08:03 PM

Hope, you have no problem. GAV operation appears normal - just takes a little try and check to get it right and then leave it alone. At least my experience.

John

eagle · 11-04-2019, 08:26 PM

Mine is not that sensitive. It'll run with the GAV closed but will be lean. Try some Seafoam in the fuel for a while, it'll clean up the fuel system.

J Franklin · 11-04-2019, 08:29 PM

I think yours is working just fine. Run it 1/4+ open, no problem.

zzlegend · 11-04-2019, 09:59 PM

Andy, i have to run mine about 1/2 open and it seems happy there.

Chuck Sea/Tac · 11-05-2019, 01:58 AM

Sponsored Links (Register now to hide all advertisements)

Unless your high altitude, 1/4 is normal.

Werner · 11-05-2019, 04:23 AM

Hallo Andy,

what you write is not a mistake. 1/4 open is only a guideline. That can vary. If the engine is cold, it must be opened further. If you are very high in the mountains, close far, etc ... .

If the valve needle sit is very well, the needle rotation also reacts very accurately. On my Roadster I feel 1/8 U immediately.

Perhaps your idle mix is a liitle bit too lean, try 1/8 turn left. -

BTW: Nice that not only I have a bumpy American language! Regards to Argentinia, have always good drives.

JoeCB · 11-05-2019, 12:00 PM

Andy , welcome to the forum, Have fun with your Model A … and your English is very good

Joe B

30 Closed Cab PU · 11-05-2019, 12:47 PM

Adjustment for IDLE Mixture Adjust Screw must be adjusted at 600 rpm or below. At 600 RPM and below GAV does not affect how motor runs, unless turned more than 1 - 11/2 turns open, So adjust this screw 1st.

GAV Adjusts Mixture from very fast idle 700 RPM up to fast running. At fast idle and above the Idle Mixture Screw does not affect the motor.

On my truck - For Cold Starting I set the GAV to 2/3 open. Start, adjust GAV to best running as motor warms.
- At fast idle warm runs best at 1/8 open. less than 1/8 - closed motor runs poorly, acts like it will stall.
- At higher RPMs open to 1/4 - 1/2 open, less than that and I get a "cough" through the carb when slowing down and also at shifting.

Run your A for best running, do a spark plug read after running fast speeds. If Plugs look good, use and enjoy your A.

Here are a couple of links to info written by a motor A vender her in teh USA. Has Adjustment procedure, and everything you would want to know and more. Also attached a link to the Instruction manual. Includes settings, how to start, and a good resource for basic info.

Hope this helps.

https://www.modela.org/idle_adjustment.html
https://www.modela.org/
http://www.motormayhem.net/model-a-f...owners-manual/

11-04-2019, 07:49 PM	#1
Andy0011 Junior Member Join Date: Oct 2019 Location: Buenos Aires, Argentina Posts: 1	GAV closed, car dies Hello everyone! I am new here and I am from Argentina. I don't speak english very well, sorry if I have mistakes! My question for the forum is that I recently revived my 29 town sedan that was sleeping for more than 6 years because it did not started. I cleaned the plugs, and I disamble the zenith carb, cleaned it and it came back to life. But I noticed that have a problem with the GAV. It acts very sensitive. If I open 1 turn to the left it sounds as if it too rich, if I try to find the 1/4 turn open the idle sounds ok to me, but if I close it just a little bit from there it begins to be irregular, and if I completely close it, the car dies. I think that it should not happen, it should be running if it is closed, so I need some help with the possible diagnosis. Thanks!!!

11-04-2019, 08:03 PM	#2
aermotor Senior Member Join Date: Mar 2015 Location: Greenville, SC Posts: 1,099	Re: GAV closed, car dies Hope, you have no problem. GAV operation appears normal - just takes a little try and check to get it right and then leave it alone. At least my experience. John

11-04-2019, 08:26 PM	#3
eagle Senior Member Join Date: Aug 2011 Location: Eagle Bend, MN Posts: 2,025	Re: GAV closed, car dies Mine is not that sensitive. It'll run with the GAV closed but will be lean. Try some Seafoam in the fuel for a while, it'll clean up the fuel system. __________________ "There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."

11-04-2019, 08:29 PM	#4
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 5,961	Re: GAV closed, car dies I think yours is working just fine. Run it 1/4+ open, no problem.

11-04-2019, 09:59 PM	#5
zzlegend Senior Member Join Date: May 2010 Location: Reseda, Calif. Posts: 2,188	Re: GAV closed, car dies Andy, i have to run mine about 1/2 open and it seems happy there.

11-05-2019, 01:58 AM	#6
Chuck Sea/Tac Senior Member Join Date: May 2010 Location: Between Seattle & Tacoma Posts: 2,354	Re: GAV closed, car dies Sponsored Links (Register now to hide all advertisements) Unless your high altitude, 1/4 is normal.

11-05-2019, 04:23 AM	#7
Werner Senior Member Join Date: Jan 2019 Location: Germany, near Aachen Posts: 1,156	Re: GAV closed, car dies Hallo Andy, what you write is not a mistake. 1/4 open is only a guideline. That can vary. If the engine is cold, it must be opened further. If you are very high in the mountains, close far, etc ... . If the valve needle sit is very well, the needle rotation also reacts very accurately. On my Roadster I feel 1/8 U immediately. Perhaps your idle mix is a liitle bit too lean, try 1/8 turn left. - BTW: Nice that not only I have a bumpy American language! Regards to Argentinia, have always good drives. __________________ Beste Gruesse aus Deutschland, Werner Ford Model A, Roadster, 1928 Citroen 11 CV, 1947 Hercules W 2000, 1976; (with NSU-Wankel Rotary Engine), Canadian version

11-05-2019, 12:00 PM	#8
JoeCB Senior Member Join Date: Nov 2018 Location: Farmington MI Posts: 284	Re: GAV closed, car dies Andy , welcome to the forum, Have fun with your Model A … and your English is very good Joe B

11-05-2019, 12:47 PM	#9
30 Closed Cab PU Senior Member Join Date: Aug 2018 Posts: 2,332	Re: GAV closed, car dies Adjustment for IDLE Mixture Adjust Screw must be adjusted at 600 rpm or below. At 600 RPM and below GAV does not affect how motor runs, unless turned more than 1 - 11/2 turns open, So adjust this screw 1st. GAV Adjusts Mixture from very fast idle 700 RPM up to fast running. At fast idle and above the Idle Mixture Screw does not affect the motor. On my truck - For Cold Starting I set the GAV to 2/3 open. Start, adjust GAV to best running as motor warms. - At fast idle warm runs best at 1/8 open. less than 1/8 - closed motor runs poorly, acts like it will stall. - At higher RPMs open to 1/4 - 1/2 open, less than that and I get a "cough" through the carb when slowing down and also at shifting. Run your A for best running, do a spark plug read after running fast speeds. If Plugs look good, use and enjoy your A. Here are a couple of links to info written by a motor A vender her in teh USA. Has Adjustment procedure, and everything you would want to know and more. Also attached a link to the Instruction manual. Includes settings, how to start, and a good resource for basic info. Hope this helps. https://www.modela.org/idle_adjustment.html https://www.modela.org/ http://www.motormayhem.net/model-a-f...owners-manual/