|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
02-06-2024, 07:50 PM | #1 |
Senior Member
Join Date: Apr 2022
Posts: 284
|
Motor shuts down
Hello everyone! My question today is…What would cause my Model A to shut down for a second or two and then fire back up and backfire? I’ve checked the gas flow to the carburetor and it seems nice and strong. The car seems to be under powered at times and then out of the blue it will cut out and then reignite
And Boom!!! Can it be a stuck valve? Any input would be greatly appreciated. 1930 Sport coupe. Thank you |
02-06-2024, 08:58 PM | #2 |
Member
Join Date: Apr 2023
Posts: 30
|
Re: Motor shuts down
Is your timing set correctly? Some form of vapor-lock?
Last edited by MilwaukeeMike; 02-06-2024 at 09:10 PM. |
Sponsored Links (Register now to hide all advertisements) |
|
02-06-2024, 09:24 PM | #3 |
Senior Member
Join Date: May 2010
Location: So Cal
Posts: 8,755
|
Re: Motor shuts down
Point gap closing up?
|
02-06-2024, 09:39 PM | #4 | |
Senior Member
Join Date: May 2010
Location: Clinton,WA/Whidbey Island
Posts: 4,106
|
Re: Motor shuts down
Quote:
__________________
www.whidbeymodelaclub.com |
|
02-06-2024, 10:55 PM | #5 |
Senior Member
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,131
|
Re: Motor shuts down
Intermittent ignition switch, does it turn on and off with a snap or sloppy is bad
Mine was intermittent when I first got it, soon after I needed a muffler, working the switch helped mine
__________________
Don't force it with a little hammer tap, tap, tap get a bigger hammer tap done |
02-07-2024, 06:54 AM | #6 |
Senior Member
Join Date: Feb 2011
Location: NNNNNNNNJJJJJJJJJJ
Posts: 6,794
|
Re: Motor shuts down
Sponsored Links (Register now to hide all advertisements)
yes it can be. In that case, add some Marvel Mystery oil to your gas and run it run it run it. we too often let our cars sit and then many diff things can happen. |
02-07-2024, 07:52 AM | #7 |
Senior Member
Join Date: May 2010
Location: Grafton,OHIO
Posts: 727
|
Re: Motor shuts down
Wire in the distributer under point plate shorting out, bad condenser, bad coil just to name a few.
|
02-07-2024, 08:20 AM | #8 |
Senior Member
Join Date: Apr 2021
Location: Central Illinois
Posts: 496
|
Re: Motor shuts down
Is the boom coming from the carb or the tail pipe? Sticking float? Boom from the carb is lean, (air leak), tail pipe is rich, (likely some black smoke).
Watch the ammeter, if it flickers, likely its in the primary ignition circuit. As said above, low quality point sets cam followers will wear quickly and allow a short to the cam from the point arm. When our coupe did this, it was a 'stumble' or 'buck', but we had no backfire / after fire. Our coupe recently set for 90 days while I worked on the drive train. After, when I first attempted to start the car, it would not fire off and run. I quickly ran sandpaper through the points, expecting it to take off. Nope. A closer look, revealed a burned and pitted point set, WOW! I had to use a magnifier to get a good look. A new points set and condenser resolved the issue.
__________________
"It ain't what you know for certain that gets ya in trouble. It's what ya know for certain that just ain't so!" |
02-07-2024, 08:41 AM | #9 |
Senior Member
Join Date: May 2010
Location: Long Island, NY
Posts: 3,472
|
Re: Motor shuts down
My guess is you have an intermittent ignition caused by a short circuit, a loose terminal connection, faulty ignition switch, or ????????????
Look for the easy things first. Good luck!
__________________
Bob Bidonde |
02-07-2024, 09:27 AM | #10 |
Member
Join Date: Dec 2016
Location: Grants Pass, Oregon
Posts: 79
|
Re: Motor shuts down
Your condenser MIGHT be going BAD. Also check the POINT GAP!
|
02-08-2024, 07:03 AM | #11 |
Senior Member
Join Date: Apr 2022
Posts: 284
|
Re: Motor shuts down
I replaced the original type points and condenser with modern style. I will surely make a checklist of all the things mentioned in your responses.. The backfire comes out of the tail pipe. Thanks everyone!!
|
02-08-2024, 04:53 PM | #12 |
Senior Member
Join Date: Aug 2017
Location: SoCal Desert
Posts: 826
|
Re: Motor shuts down
Mine did that at it was the ignition armored cable. The insulation inside the cable became old and dry and was breaking off in three different places. The wire inside was shorting out to the outer cable. I replaced the armored cable and all was good. I left the cable clamp off of the cable since I had no intention of wanting to break a seal on the head just to remove the distributor.
Regards Bill |
02-08-2024, 06:10 PM | #13 |
Senior Member
Join Date: Apr 2022
Posts: 284
|
Re: Motor shuts down
Good to know Bill thank you I will check that as well!
|
02-08-2024, 06:40 PM | #14 |
Senior Member
Join Date: Jun 2022
Location: Baldwinsville NY
Posts: 174
|
Re: Motor shuts down
Ignition coil can short out when hot, not sure if there is a way to test it.
|
02-08-2024, 08:35 PM | #15 |
Senior Member
Join Date: Jan 2012
Location: Western North Carolina
Posts: 3,903
|
Re: Motor shuts down
The unburnt gas/air in the muffler will ignite causing the boom.
To test to see if the the coil is failing when hot, use the cool spray that is used in the electronic field to test for heat related component failure, or ice. As the other responses have said, it is likely an intermittent connection or short somewhere in the ignition system.
__________________
A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past. |
02-08-2024, 10:38 PM | #16 |
Senior Member
Join Date: Apr 2021
Location: Central Illinois
Posts: 496
|
Re: Motor shuts down
Lenny, now that you have the modern upper plate, you can temporarily bypass the switch, the heavy cable and the infamous black wire from the bottom plate. Unhook the coil to switch wire and tape the end, run a jumper from the coil to the top plate direct via the spark adjustment opening. Tape the end of the wire from the lower plate, too. Tie wrap the jumper wire to the spark arm of the upper plate. Use your pos + ground cable at the battery, the safety fuse or the fuel shutoff to kill the engine.
__________________
"It ain't what you know for certain that gets ya in trouble. It's what ya know for certain that just ain't so!" |
02-09-2024, 03:56 AM | #17 |
Senior Member
Join Date: Apr 2022
Posts: 284
|
Re: Motor shuts down
Wow thank you all so much! Getting all this much appreciated advice really helps motivate
And boost confidence in finding the problem. I love learning more and more about these fun little cars! |
02-09-2024, 08:00 AM | #18 |
Senior Member
Join Date: Feb 2011
Location: Lincoln, Nebraska
Posts: 1,910
|
Re: Motor shuts down
See if you can borrow a known good distributor from someone else and run that for a while to see if the problem goes away. Will narrow things down a bit.
__________________
Dave / Lincoln Nebraska |
02-09-2024, 06:31 PM | #19 |
Senior Member
Join Date: Jan 2019
Location: Florida Panhandle
Posts: 585
|
Re: Motor shuts down
Had a similar problem on a boat. Turned out to be a bad wire connection that lost continuity when the connection warmed up. Try shaking all the connections while the engine is running. Good Luck.
|
02-09-2024, 07:19 PM | #20 |
Senior Member
Join Date: Nov 2018
Location: Kankakee, Illinois
Posts: 225
|
Re: Motor shuts down
I just had a similar problem yesterday. My truck would miss here and there. I notice the engine stumble at times, then suddenly die. Turns out my wire connectors to the ignition switch would short out to the gas tank. I bent them down a bit and taped them up. Problem solved.
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|