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Old 05-27-2021, 06:49 AM   #3
WHN
Senior Member
 
Join Date: Mar 2017
Location: Connecticut Shoreline
Posts: 1,815
Default Re: Don't go changing parts

Quote:
Originally Posted by Jacksonlll View Post
I just sent this in to MARC, but this may be handy to some Barners.

Don’t Start Changing Parts !!!

Far too many Model A owners try to fix their car by simply exchanging parts until their car runs. This is a very long shot and you won’t learn anything.
If your car ran good last week or last month, or even last year, it’s probably something simple that needs attention. People put a new carb on, new condenser, and even retime the engine. Those parts did not go bad by just sitting there a few months. The timing did not change. The condenser did not decide to go bad.
If it ran rough when it was put to bed, then you might have other issues, but you have to find out where the problem is, and then fix that.

The easy things to check:
Dirty points: Just slide a business card or thick piece of paper through the point gap with the points closed a few times to get the dirt and dust off of them.
Fouled plugs: Pull out a plug and look at it. If it’s black and fuzzy, clean it. Don’t put new ones in just because the old ones are fouled. You should clean the fairly often anyway.
Is the carb getting fuel? Hit the starter while giving it a little choke, then stick your thumb into the carb near the choke butterfly and if it comes out wet, fuel is probably not the problem. Remember; 90% of all fuel problems are really ignition problems. Just an old saying. If you do pull out a dry thumb, then chase it down until the fuel is flowing.
Quick check of the electrical circuits: Honk your horn. If no Ahooga, then your fuse is probably blow or missing. Same thing with the lights. Try them. If that is OK, you do have power going into your system.
Take your simple test light, (You better have one of these), and connect one end to ground and touch the other end to both terminals of the terminal box. Both should light your test light. If not, chase it down. The problem is the ammeter or it’s connections. Touch both terminals on the coil. With the key off, you should have power to both sides. If not, you are zeroing in on your problem. Somewhere between the ignition switch and the passenger side of the coil is touching ground.
Turn the key on and open your points and block them open with a stick or piece of paper. You should have power at the movable point arm. If not, then your problem is between the driver’s side of the coil and the point arm. Could be the ignition switch or a loose connection. If not, the circuit leading to the points is open. Power is not getting from the passenger side of the coil to the point arm.
If the open circuit is within the distributor, things get a little more complicated, but you know where the problem is.
If all is OK to this point, close the points. If the cam will not let the points close all the way and make contact, then rotate the engine until they do close. Put the car in third gear and roll the car a bit. This will ground the circuit all the way to the passenger side of the coil. You should not have power to the point arm or the passenger side of the coil. Remember; key on and points closed.
Play with this with a wiring diagram in front of you to help you understand what is going on, or call someone and start asking questions. Ask a club member, and if there is no club near you, join one as an out-of-state member. Join Oakleaf Region. We all need someone we can call and help us with our cars.
The Model A engine wants to start and run. Get things correct and let it run.

Some cruel things that can shut you down:
These things stump the experts:
Intake air leak at the manifold-to-engine, or the carb-to-manifold. This happens when you are pretty sure you have fuel and spark. Spray a little starter fluid around these joints as you try to start it, or when it is idling rough. Make sure those four manifold nuts and the two carb screws are snugged up. Easy fix if this is the problem.

Corrosion between the Battery cable fitting and the wire, itself. This is a crimped joint and can fool you. It will light your test light or show continuity, but it can’t handle heavy current.
Ammeter: An ammeter can have an intermittent open circuit. Don’t trust it to be good.
Fuse holder on top of the starter. These are put together with small aluminum rivets that can easily loosen up and cause an intermittent open circuit. Take it off and use an in-line fuse.
Circuit from the ignition switch to the distributor can be shorted to ground. If it is screwed in too far, it can become grounded, or it can have a short in the end fitting that screws into the distributor. Very hard to find.
Internal short within the modern point set. A lot goes on keeping things from shorting on this small part. A lot of little pieces that keep things apart. Hard to find.
Inline fuel filter. Just be aware that some filters need some pressure to push the fuel through. Test it. Make sure it is free flowing.
Jack Bahm Oakleaf 2021
Great advice. I tell people the same thing all the time. Even cars stored for years will come right to life. Gas, points, and plugs, first place to check if your baby won’t wake up.

Enjoy.
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