Engine Quitting

Coneross-A

Coneross-A

Member
Hello all,

My 1929 Fordor has an issue with the engine quitting. This always seems to occur when I've been driving around long enough for the engine to reach operating temperature. Engine runs fine until I shut off the car. When I come back and then restart the engine, it will act like it's not getting gas, and quit. Holding the choke will get the engine to hit, but it won't stay running. Usually a roll start is what's required to get it going. After that, it runs fine. The only thing I can think of is maybe some trash moving around in the carburetor.

Any thoughts?
 
My Model A acts the same way on days when the temp is warm and when I used to put the 10% corn crap gas in my car. Since I now only use the good gas without the corn crap, the car runs fine.
 
How long does it take for this to happen ? It appears from the post that if the engine sits a short [ hour or less] time this happens and if it sits for a longer period of time its OK.
Make sure the fuel line always runs/pitches downhill from the firewall to the carburetor. You don't want any level or uphill portions of the line to help prevent fuel from boiling and locking the flow.
I've also made a light sheetmetal 'deflector' that bolts to the manifold and exhaust clamp to keep exhaust heat from the carb inlet.
 
I would suspect the coil. When you shut the engine down the temperature under the hood rises well above the operating temperature. The coil becomes hotter and the fine secondary windings will expand and can short out. There is only a fine coating on the windings for insulation. When the engine compartment cools down the expansion decreases, the short goes away, and all is well again.

I have seen this happen a number of times and it is hard to diagnose. The only way is to try a replacement coil. Most instances attributed to vapor lock are actually the coil failing temporarily.

Tom Endy
 
FWIW: Bit of Trivia History from past Marine Gas Engine Rural Experiences years ago:

Per Mr. Endy's response #4, "hot" coil failure is exactly why not just a few, but "all" commercial fishermen in the teens, 1920's & 1930's hated, and refused to depend on vintage outboard motors.

Easy to start cold, until "coil(s)" inside flywheel(s) got hot, softened the "vintage type" varnish coating, shorted out coil wires, and these outboard motors with "old" vintage coils with "old" insulation would "never" start hot.

Muncie & Neptune spelled "sinkers" and/or boat "anchors" years ago for serious commercial fishermen going out to sea & depending on coming home for their livelihood.

Also, years ago, Ford sold lots of far more reliable Model T, A, & B engines to install in boats.

Many other commercial fishermen, with inland freshwater fishing, also hated old outboard motors with failing overheated coils & resorted to the very reliable inboard hopper-water-cooled "hit & miss" Lockwood-Ash and Fairbanks-Morse (2) cycle engines which could run clockwise or counter clockwise. ***

"Hit & Miss" (2) cycle engines hardly ever wore out like (4) cycles of the day because oil was mixed with gas which provided much needed upper cylinder lubricant where most engine wear occurs in all in (4) cycle engines which use only gas & no oil.

Likewise, well experienced & more intelligent mechanics knew back then that regardless of the B.S. published by engine manufacturers trying to sell parts, that top cylinder lubricant could allow (4) cycle engines to go sometime like over 50,000 miles in lieu of the normal 8,000 miles before needing a ring job .......... even without having much needed oil filters and air filters on vintage dirt and gravel roads.

*** If these old fishermen allowed their "Hit & Miss" engine to idle, & they rotated their magneto 180 degrees, one would hear what sounded like a gun shot ...... then the engine ran backwards and these old commercial fishermen had boats with instant "Reverse" without the expensive cost of a marine transmission.

No start when hot ...... per response #4 ..... could be coil.
 
Tom Wesenberg said:
My Model A acts the same way on days when the temp is warm and when I used to put the 10% corn crap gas in my car. Since I now only use the good gas without the corn crap, the car runs fine.
Click to expand...

Suffice to say, Tom is 100% spot on... I've only just now tried 100% gasoline (1st tank of it) and will tell you my car runs with more power, smoother (100% gas has more energy than 10% corn juice)... I'm sold on it... thankfully I can buy it near me... a bit more costly than 10% corn juice laced gasoline but I think worth it... If you can buy it, try it... :)
 
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Patrick,
Has that heat deflector helped? I'm thinking along the same lines. After a twenty five mile trip, on some days, or idling after a trip it will start acting like it's lean and I've had some success enriching the GAV. Once I'm back on the road it's fine again. I'm imagining the fuel vaporizing in the bowl.
Thank gents,
Al
 
Al 29Tudor said:
Patrick,
Has that heat deflector helped? I'm thinking along the same lines. After a twenty five mile trip, on some days, or idling after a trip it will start acting like it's lean and I've had some success enriching the GAV. Once I'm back on the road it's fine again. I'm imagining the fuel vaporizing in the bowl.
Thank gents,
Al
Click to expand...





I can't say I've had vapor lock in an 'A'. I have had some slight difficulty when starting hot/warm on warm days. With all the talk here about vapor lock, I just started looking for the heck of it.
I replaced the fuel line making sure every bit of it had down pitch/slope and made the deflector just to keep some of the hot exhaust air away from the carburetor throat.
It starts right up in any conditions its been in since then. So, I can't say which one did it for sure.
 
I wasn't really concerned with an ignition issue, but, now thats its been brought up, its a good one.
Just another thing to consider. An oil coil will not work upside down. The tower must point skyward. A newer epoxy coil [ or original style] doesn't care about such things.
[ I found that out the hard way 50 yrs ago with a VW.]
 
Al 29Tudor said:
Patrick,
Has that heat deflector helped? I'm thinking along the same lines. After a twenty five mile trip, on some days, or idling after a trip it will start acting like it's lean and I've had some success enriching the GAV. Once I'm back on the road it's fine again. I'm imagining the fuel vaporizing in the bowl.
Thank gents,
Al
Click to expand...





I can't say I've had vapor lock in an 'A'. I have had some slight difficulty when starting hot/warm on warm days. With all the talk here about vapor lock, I just started looking for the heck of it.
I replaced the fuel line making sure every bit of it had down pitch/slope and made the deflector just to keep some of the hot exhaust air away from the carburetor throat.
It starts right up in any conditions its been in since then. So, I can't say which one did it for sure.
 
If I were having starting troubles after gassing up, I would try opening the R/H side of the hood, first, to "maybe" keep the carb cooler???
Bill W.
 
To everyone who responded. I apologize for taking so long to get back. Major unforseen fire drill at work prevented me from doing a lot of things.
 
One or two quick pulls on the chock is how I typically start it cold. I never choked it when warm before. I only started using choke after running when this issue started.
 
Tom Wesenberg said:
My Model A acts the same way on days when the temp is warm and when I used to put the 10% corn crap gas in my car. Since I now only use the good gas without the corn crap, the car runs fine.
Click to expand...

I have been running methanol free gas since I bought the car in June. I agree with you, It is better to avoid ethanol gas. Aside from other issues, Ethanol is a desiccant and will draw water.
 
Tom Endy said:
I would suspect the coil. When you shut the engine down the temperature under the hood rises well above the operating temperature. The coil becomes hotter and the fine secondary windings will expand and can short out. There is only a fine coating on the windings for insulation. When the engine compartment cools down the expansion decreases, the short goes away, and all is well again.

I have seen this happen a number of times and it is hard to diagnose. The only way is to try a replacement coil. Most instances attributed to vapor lock are actually the coil failing temporarily.

Tom Endy
Click to expand...

I have a spare coil that I will install today. I will post the results. Thanks to everyone who responded.
 
My coupe also runs ruff and does not want to idle after it sits a while after a drive in 90 degree weather. Then restarted. In my case I think the auto light heater manifold makes more heat in the engine compartment. But real gas would probley help.
 
Coneross-A said:
One or two quick pulls on the chock is how I typically start it cold. I never choked it when warm before. I only started using choke after running when this issue started.
Click to expand...




I may have mis-stated a post. During a hot start it will start right up but at times stumble a bit for a minute. It hasn't done that since the changes.

Unless a warm/hot start is attempted within a very short time period [maybe 5 minutes], then a bit of choke is needed. This a tired 1961 engine with 45# compression that doesn't smoke, leak or use any oil.
 
Well, I changed out the coil this morning and went for a drive. I stopped, and the engine was off long enough to fill the gas tank. (with ethanol free gas). Started up fine after fuelling...and I drove for 15-20 miles with no problems. When I got home. I left the car at the bottom of the driveway so I could get leaves out of the garage before putting the car up. I started her up, and proceeded up the drive way. Within 20-30 seconds it was sputtering as if running out of gas, and then quit. The engine again refused to start. A hard choke would get it to hit, but it would not stay running. After letting it sit and cool for 10 minutes or more, it started right up and ran smoothly as if nothing had happened.

So...back at square one. It was in the high 50's to low 60's today. So I don't think it is excessive heat. The motor is not running hot because the moto meter wasn't showing any red at all.

I have a spare carburetor that I am not too sure of at this point. I will try it next. I'm also wondering if a weak condenser could be the culprit.
 
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