The Ford Barn

Oberfranke · 07-07-2021, 01:25 PM

There is a pop in the exhaust when shifting gears and reducing the gas. The ignition should not be the problem. Everything is well adjusted here. What could be the cause?
Greetings from Bavaria

J Franklin · 07-07-2021, 02:04 PM

Rich fuel mixture and air leaks in the exhaust system can cause that. It is not uncommon.

old31 · 07-08-2021, 08:51 AM

Where do you have your gav turned to? 1/4, 1/2, 1?

Y-Blockhead · 07-08-2021, 09:28 AM

You're a little on the lean side, open the GAV a little.

J Franklin · 07-08-2021, 12:15 PM

A lean mix usually pops in the carb not the exhaust in my experience. But anything is worth a try.

Oberfranke · 07-08-2021, 02:22 PM

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The GAV is 1/4 open. I will see if there is a leak at the manifold or exhaust. I think with flush water or with a bird feather I can detect a leak.

CatMan1 · 07-09-2021, 07:16 AM

This explains what I'm seeing, or hearing as well. I have exhaust leaks around the manifold and where the exhaust pipe clamps on. I also get this popping sometimes when I'm going downhill and letting off the gas.

Ed in Maine · 07-09-2021, 03:30 PM

Get a sleeve that mounts between the exhaust pipe and the manifold to stop air leaks into the exhaust system. Ed

old31 · 07-09-2021, 03:43 PM

Remove your fan belt and start the car. It will be easier to hear and see leaks.

Werner · 07-09-2021, 03:56 PM

Mageres Gemisch + zu später ZZP fördern Auspuffpatschen.

DRG-ler · 07-10-2021, 01:22 PM

I have the glitch too, but my manifold and exhaust are definitely tight (re-sealed). Is the consumption of 18 liters so little that the mixture is too lean? GAV stands at 1/4. I would also argue that it tends to run too fat.

Greetings from Berlin

Andy

Oberfranke · 07-11-2021, 07:19 AM

I have not had a backfire since I opened the GAV to about 3/4. The exhaust seems to be tight. If not, oil would probably leak out. I will now also give more early ignition.
But why didn't I have this problem before?

Y-Blockhead · 07-11-2021, 08:57 AM

Quote:

Originally Posted by Y-Blockhead

You're a little on the lean side, open the GAV a little.

Quote:

Originally Posted by J Franklin

A lean mix usually pops in the carb not the exhaust in my experience.

Quote:

Originally Posted by Oberfranke

I have not had a backfire since I opened the GAV to about 3/4. The exhaust seems to be tight. If not, oil would probably leak out. I will now also give more early ignition.

As I posted in post #4. I am happy that worked out for you. My Town Sedan did the same when I had my Zenith on if the GAV was closed a little too much.

07-07-2021, 01:25 PM	#1
Oberfranke Junior Member Join Date: May 2020 Location: Germany, in Coburg (Bavaria) Posts: 24	Bang in the exhaust There is a pop in the exhaust when shifting gears and reducing the gas. The ignition should not be the problem. Everything is well adjusted here. What could be the cause? Greetings from Bavaria

07-07-2021, 02:04 PM	#2
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 5,959	Re: Bang in the exhaust Rich fuel mixture and air leaks in the exhaust system can cause that. It is not uncommon.

07-08-2021, 08:51 AM	#3
old31 Senior Member Join Date: Jan 2016 Posts: 2,094	Re: Bang in the exhaust Where do you have your gav turned to? 1/4, 1/2, 1?

07-08-2021, 12:15 PM	#5
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 5,959	Re: Bang in the exhaust A lean mix usually pops in the carb not the exhaust in my experience. But anything is worth a try.

07-08-2021, 02:22 PM	#6
Oberfranke Junior Member Join Date: May 2020 Location: Germany, in Coburg (Bavaria) Posts: 24	Re: Bang in the exhaust Sponsored Links (Register now to hide all advertisements) The GAV is 1/4 open. I will see if there is a leak at the manifold or exhaust. I think with flush water or with a bird feather I can detect a leak.

07-08-2021, 09:28 AM	#4
Y-Blockhead Senior Member Join Date: Jul 2011 Location: Redondo Beach, CA Posts: 5,848	Re: Bang in the exhaust You're a little on the lean side, open the GAV a little.

07-09-2021, 07:16 AM	#7
CatMan1 Senior Member Join Date: Jun 2021 Location: Pella, IA Posts: 336	Re: Bang in the exhaust This explains what I'm seeing, or hearing as well. I have exhaust leaks around the manifold and where the exhaust pipe clamps on. I also get this popping sometimes when I'm going downhill and letting off the gas.

07-09-2021, 03:30 PM	#8
Ed in Maine Senior Member Join Date: May 2010 Location: Washington Cty., ME or Flagler Cty., FL Posts: 1,106	Re: Bang in the exhaust Get a sleeve that mounts between the exhaust pipe and the manifold to stop air leaks into the exhaust system. Ed

07-09-2021, 03:43 PM	#9
old31 Senior Member Join Date: Jan 2016 Posts: 2,094	Re: Bang in the exhaust Remove your fan belt and start the car. It will be easier to hear and see leaks.

07-09-2021, 03:56 PM	#10
Werner Senior Member Join Date: Jan 2019 Location: Germany, near Aachen Posts: 1,153	Re: Bang in the exhaust Mageres Gemisch + zu später ZZP fördern Auspuffpatschen. __________________ 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

07-10-2021, 01:22 PM	#11
DRG-ler Senior Member Join Date: Dec 2018 Location: Berlin / Germany Posts: 182	Re: Bang in the exhaust I have the glitch too, but my manifold and exhaust are definitely tight (re-sealed). Is the consumption of 18 liters so little that the mixture is too lean? GAV stands at 1/4. I would also argue that it tends to run too fat. Greetings from Berlin Andy

07-11-2021, 07:19 AM	#12
Oberfranke Junior Member Join Date: May 2020 Location: Germany, in Coburg (Bavaria) Posts: 24	Re: Bang in the exhaust I have not had a backfire since I opened the GAV to about 3/4. The exhaust seems to be tight. If not, oil would probably leak out. I will now also give more early ignition. But why didn't I have this problem before?