No Start - Loud Pops

[AAzz44]

Ok. Quick update.

Thank you for the advice on the timing. Finally got it right.

Now for the next issue.

The Car will start and idle however really rough. It has a new carburetor and hi boy air filter both from Macs online.
I also installed a new fuel line and glass filter.
Flow is good with little to no particles.

I tried adjusting the carburetor idle screws but no luck.

Any ideas on this one.

Feel like it probably something simple. I just know I’m real close to being able to take her on the road.

[1crosscut]

Okay you are getting closer.

Did you check/set the points gap?

You need to know that the gap is correct before making other adjustments.

If your gap is correct then check for leaks at the intake/exhaust manifolds.

With the engine running spray ether (starting fluid) around the mating surfaces at idle and see if the engine speed changes. If it does you have a leak.

Also check to see that the connection between the carburetor and the intake manifold is tight.

[AAzz44]

Dave - sorry but what tool do I need to check the points?
I’ve heard that multiple times but don’t know how to do this.

I’ll check for leaks in the meantime.

Thanks.

[1crosscut]

You will need a feeler gauge.
Any auto parts store will have them. Here is a link to one at Harbor Freight.

https://www.harborfreight.com/Feeler...-Pc-63665.html

You will need to rotate the engine so that the high spot on the distributor cam is under the rubbing block of the movable arm of the points opening the gap between the points. Measure the distance of the gap by using the different thicknesses of the feeler gauge blades.

Here is a link that shows the gap that you need to measure and also shows the position of the high point on the cam in in relationship to the movable points arm.

https://modelagarage.com/service_bul...park-plug-gap/

It is easier to loosen the set screw on the rotor to turn the cam to adjust the point gap instead of turning the engine over to open the points gap but that would mean you would need to re time the engine again. Instead just remove the spark plugs so you can turn the engine over without compression working against you.
I like to check the gap on all four of the high points of the cam lobe.

To adjust the gap you will need to loosen the lock screw on the non moving part of the points block before trying to turn the adjustment screw in or out. Lock it down afterwards and re check the gap.

[30 Closed Cab PU]

Without re-reading this string, do not know if previously mentioned. When setting the points gap and timing turning the motor is tons easier with teh spark plugs removed. Not fighting the motor compression.


Or if just checking the points gap, loosen/remove the distributor holding screw and pop the distributor up off the head. Then the distributor shaft is free and the cam can be turned without loosening the cam screw (if gap is OK, no need to re-time when reassembled).

[Jim/GA]

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Originally Posted by AAzz44

Dave - sorry but what tool do I need to check the points?
I’ve heard that multiple times but don’t know how to do this.

I’ll check for leaks in the meantime.

Thanks.

Where in the Greater Houston area do you live? I can probably connect you with a Model A expert in 5 minutes to assist. There are hundreds of them in your area.

[rocket1]

New fuel line installed,they usually come with the ferrules loose on the tube,the tubing should not be pushed to far into the carb.Also leave the air filter off till you sort out your problem,"A"never came with an air filter.

[AAzz44]

Kingwood. So northeast Houston.

[Nick in Fayetteville]

The starter switch is not related to your other problems. Just a thought... change coils. Back firing is an electrical problem rather than a fuel problem.

[Jim/GA]

Originally Posted by AAzz44

Kingwood. So northeast Houston.

Contact these guys. Lots of people up that way that can help you.

https://www.pineywoodmafc.com/

[AAzz44]

Appreciate everyone's advice. It ended up being the Gap on the Spark Plugs. Car is running 10x better. Although still a little rich. I guess thats the next hurdle here.

It smells really rich at idle when cold and warm. I have adjusted the GAV but noticed if I turn it Clockwise too much it will kill the engine. Right now its about half open.Cant think of what else to do here moving forward.

Thanks again for all the suggestions.

Mike A

[30 Closed Cab PU]

Plugs - when you had them out and adjusted the gaps, was the center porcelain in the middle of the plug black/sooty? If yes it is an indication the carb is running rich. It is normal for the outer ring and the electrode arm to be somewhat black, but should not have excessive sooty fluffy buildup.


At slow idle have you tried adjusting the Carb idle mixture screw?


At any time getting black exhaust smoke?

[ryanheacox]

Glad you got it but how far out was the plug gap for you to be getting these issues??


As far as the GAV, you can close it down way more than half a turn. What will it do at 1/8- 1/4 turn? A lot of cars will still run with the GAV completely closed. Many A's run rich since the new jets sold are oversized.

[AAzz44]

For being new plugs I would say YES on the black and sooty.

I've tried adjusting the Carb Idle mixture and the GAV with really no luck.
Its a brand new Carb too, so I would expect it to be running a little better.

[30 Closed Cab PU]

Originally Posted by AAzz44

For being new plugs I would say YES on the black and sooty.

I've tried adjusting the Carb Idle mixture and the GAV with really no luck.
Its a brand new Carb too, so I would expect it to be running a little better.

Who did you get the new carb from? Hopefully someone who uses flow tested jets and tests the carbs on a car before shipping. If you suspect carb, see if someone will loan you a known good carb to try.



Do you get any gas drippage from the carb?



Seems you are running rich, usually a carb issue. Leaky intake manifolds cause lean running.


What's wrong with the old carb? If you still have it you caould try it, got nothing to lose.

[AAzz44]

Originally Posted by 30 Closed Cab PU

Who did you get the new carb from?

Purchased new from MACs Auto Parts. "Zenith 1 Air Balanced"
Hopefully someone who uses flow tested jets and tests the carbs on a car before shipping. If you suspect carb, see if someone will loan you a known good carb to try.



Do you get any gas drippage from the carb?
No


Seems you are running rich, usually a carb issue. Leaky intake manifolds cause lean running.


What's wrong with the old carb? If you still have it you caould try it, got nothing to lose.

I actually tried that and was having the same issue.

[AAzz44]

In regards to the GAV. Ill turn it all the way off and see if I can adjust the idle.

[Jim/GA]

Originally Posted by AAzz44

In regards to the GAV. Ill turn it all the way off and see if I can adjust the idle.

Better to leave GAV 1/4 turn open. That is normal position for engine that's warmed up; 1/2 turn open when cold.

Adjust mixture with engine at normal operating temperature. That means go drive it for 20 minutes before adjusting.

If idle RPM is low enough, GAV does not impact idle mixture. But if you have RPM up high enough, it pulls fuel from the main jets (which are fed by the GAV).

Make sure ignition points are gapped to 0.020"

[AAzz44]

Thanks Jim. Ill try adjusting again after i drive it for a bit.

In regards to the ignition points. I have an FSI Zipper.....should I still try and adjust?

Mike A

[Jim/GA]

Originally Posted by AAzz44

Thanks Jim. Ill try adjusting again after i drive it for a bit.

In regards to the ignition points. I have an FSI Zipper.....should I still try and adjust?

Mike A

No, there is nothing to adjust there but the initial timing. No points.

Use the timing pin to set #1 piston at TDC. Then take the cap off of the distributor (leave the body on), gently turn the rotor clockwise to take out any slack, and take a picture of the rotor straight down from above it. Post picture here. We want to see the position of the big brass tab on the rotor relative to the #1 pin inside the distributor body. This is to check your initial timing.