Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Just dont get this. Running so nice and then starts to cough and dies.. Wait a bit, i advance the spark and it starts, running again fine and the same thing 15 minutes later.. open the GAV a bit and give it gas, dies again.. 5 min later starts and is fine for the rest of the day....what do you think people... Some junk in the carb or what??:mad:

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

So it's not vapor lock...

I think you have junk in your fuel line. You could disconnect your fuel line from the carb, turn on the fuel shut off valve and see if the fuel flows smoothly.

I woulds pull the shut off valve and check that.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

That might be the culprit all along. Very very frustrating. SO whats new with a Model A....HA! i also thought i might have junk in the carb clogging the jets??? possible correct?

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

first thing, when it stops, remove the gas cap and listen carefully . Does it make a sucking sound as air rushes into the tank? that's a bad cap. Drive it with the cap loose. If its the cap, that will stop the problem, so replace it with a good one.

it does sound like fuel flow restriction, but could be electrical too. Does it spark when its dead? if not, check coil or condenser.

If it sparks, check fuel flow. Some causes of restriction:
poorly vented cap

junk in the tank clogging the outlet. Use a flashlight and look.

junk in the shut off valve.

junk in the sediment bowl

fuel line extends more than 1/8th inch beyond ferrule at either end of the engine compartment line

junk in the carburetor screen

junk in the float valve

junk in the main jet

junk in the channel below the main jet that periodically floats into the jet ..remove the drain plug, draining gas into a cup and check.

remove the fuel line at the carb, flow should be strong, not a dribble. Some guys say it should flow like a 14 year old, not a 60 year old. If its strong, look in the carburetor for problems. If its weak, isolate the problem by checking for flow out of the shut off valve. If its weak, the problem is in the tank or valve. If its strong, the problem is between the valve and carburetor.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Could be just the vent in the Gas Tank Cap. Had similar problem with my speedster.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Brand new cap and checked that.:confused:

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Although I have a similar problem, it's not as severe. I'm crusing along with the mixture around 1/8 open and going about 45 MPH. Then, power loss and carb backfire. I open the mixture to 1/4 and then it gets better.

Later,I can return to 1/8 open O.K.

I have cleaned out the sediment bowl, but that's all.
The gas shutoff valve is hard to turn, and it sounds like I need to drain/check the fuel system.

Marc

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I went that route by opening up the GAV also and it did help some, but this just conked out... I think based on all i am reading and past members that it must be some clogging of the fuel line and junk in the carb.. Just hard to work on when on the TOLL WAY and they are going past at 70mph

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

in the pic of your new cap on the other thread, I did remark that type of repro cap is known for this. Drive with the cap past the lock, but not tight and see what happens.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Sounds like a loose chunk of something, most likely rust, is sometimes blocking the fuel flow. I would first try probing around with magnet in the tank see what it finds. A standpipe filter in the shutoff valve would be my second choice.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

This may be somewhat repetitive... but:

(1) Make sure you have a steady, strong fuel flow from the tank to the carb, AND

(2) Drop the bottom half of the carb and (assuming it's a recent rebuild) blow out ALL passages (both directions) with compressed air.

You might be surprised.

It doesn't take much of a rust flake to affect performance.

Best of luck.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

The original metaphor I created was "a young boy proudly writing his name in the snow, not an old man laboring to keep his shoes dry."

Critical missing info is the speed when the motor dies: Is it at idle or high speed or any speed or under load or?? It takes surprisingly strong flow to do >45 mph, but not much to idle.

IF you can keep it idling, a quick check to clear a plugged jet is a maneuver I call the carburetor Heimlich. Open passenger side hood with motor idling. Momentarily race engine with throttle rod while simultaneously popping other hand over carb intake throat (probably good idea to wear a glove, but I usually don't). Immediately, before engine dies, release throttle and remove hand. This creates an immense momentary suction that, in my experience, will pull any lodged particle on through and provide an immediate fix, until the next chunky comes along.

Based on what I've read above so far, neither vapor lock nor electrical problems have been ruled out. The "cough, cough" part of your question suggests gas starvation, but sometimes a failing condenser or some other electrical issues will do that, although the dead stop is probably more common.

Steve Schullery

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Mark, have you been in the distributor yet? When I first got my roadster, it ran then died, found the pigtail at the bottom plate was hanging on by a thread, the remaining bits of wire were shorting out. Could be a fraying pigtail?

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Steve , that,s a very good trick. Learned to do the same from my Grandpa.

Gerard

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Before you too much further, I would sure check out your fuel tank and be sure it is clean. Drain it into a container, then use a flashlight to inspect the inside of the tank. If it is rusty at all, you will continue to have problems, either with enough fuel flow, or with particles in your carb. If it is slightly dirty, then the suggestion of the stand up filter in the bottom of the tank will be a big help, until it also clogs. It really needs to be clean to have a good running car!

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

How new? Did you have the problem before the new cap?

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Mark, forget the gasoline issue for a while. Have you checked your ignition switch and ammeter connections. Remember shiny,bright and tight. If those connections are at all loose they will heat up to a point of no longer connecting hence the car stopping. Then wait 15 minutes and it magically starts up. The reason..........the connections have cooled down enough to re-connect. you drive down the road and the whole process repeats itself. I had this issue on a 77 Chevy low rider I built a few years back. I spent $600 chasing the same ghost. finally a savvy auto electrician knew before he even looked at the truck. I limped into his shop. We let it cool for twenty minutes. He fired it up and reached up under the dash tugging on the main ignition wire. Died right then and there. "Common problem on 77 Chevy trucks" he said. "pick it up at 5pm and bring a hundred dollars.

Grins and Giggles
 

Have you messed with the ignition cable going into the distributor bottom? If it is threaded in too far it could cause the buss tail to short intermittently.

GW

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I had a similar problem with my 28. It would run then spit and sputter and die. if i was lucky it would fire back up after a few minutes and let me get part of the way back home and usually die again. then one day it wouldnt start after it died. It turned out to be the condensor. i went through a lot more trouble then i needed too to figure that out. Changed the condensor and now it runs just fine. The heat from the motor got to the condensor, which i have heard is fairly common for older condensors.

Might not be the problem but it doesnt hurt to check and it is very cheap and simple to replace

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Will report more when i do these things and thanks again!

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Jumping in late, here, but I had the same problem. It seemed to happen most -- every time! -- I left the church parking lot! Not being one to hang around for cookies, I (we, Jan kind of agreed about the cookies) was usually first out and down the drive. Whooosh. He'd die. Then, the rest of the congregation would catch up and have to get out of their cars and give me a push.
I "fixed" the problem by giving the carb I'd rebuilt to a very talented hired guy who made it work like a champ. No more problem. No more sweaty friends.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

HIRED GUN -- not hired guy. Sorry Howard.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

It just needed a touch of the master's hand. Zeinth's know when they are put together correctly ... by an amatuer!

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

i had a fuel starvation problem and how i confirmed if it was the carb or the fuel delivery system was when it died out i turned off the fuel shutoff right away to not let any more flow to the carb. then pulled off the carb and opened the bowl to see where my fuel height was. in my case the fuel height was very low and the problem was the line was pushed to far in the carb..

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Fuel Delivery or spark died. Best guess. In no particular order...

Fuel
Compression
Spark
Timing

It has to run. Says so in the book.

Interestingly enough at our spring Model 'A' clinic George showed the fellows an after market cheap set of points bolted properly down to the upper plate.

Spark: Well let me tell ya, the Cooper conductor wrapped to the same rad [arch] as the piece of spring steel would bulge out at low speed and go to ground. Cutting off the spark. Not so bad at higher speeds. Everybody had a chance to see the damaged conductor area where the spark jumped to ground. Like a miniature weld.

Gas delivery: Clean the screen, a lot. Pull the line off the carb. Turn on the gas see if it flows. It likely does.
Carb. Float, float valve, a sticky shut-off from the float valve, main jet fouled, sticky green gelatinous mess from ethanol. Any air filter in the way of air sneaking up the carb.

Gas tank venting? No after market fuel filters in the way of gas flowing.

Timing, warms up points move, spark goes away.
You do have a positive drive between the cam to oil pump, and cam to distributor. Nothing that is suppose to be 'cogged together' just turning with friction after a shaft broke. Honest! I had a 1500 cc VW with a broken crank shaft. It ran but not well. Two complete pieces. Anyway...

Compression. I don't think that's the problem.

I know this is no help. I'd start over with a very very good tune up.

skip.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I has a simaler thing although in my case it would just die and coast over to the side of the road then wouldn't start for 10 minutes and then would run fine. I cleaned the carb about 15 times and rebuilt it twice and never fixed it . Turned out to be an intermittent fault in the ignition lock. Karl

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I had the exact same symptoms with mine. I tried all the above remedies to no avail. Finally, I decided to go through the wiring piece by piece. The first thing I did (just by luck) was to take the instrument panel off. I found that one wire to the ignition switch had a loose nut and was just hanging on by a small thread of wire. Once I fixed that, it hasn't happened again.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Dear Mark Maron,
1st off, thank you for you excellent problem description.
Did you fix your sedan as yet?
I searched The Barn for the exact problem you were having.
Why? Because my 31 Coupe has the same exact problem.
Next I want to thank all you flathead enthusiasts for sharing your years of knowledge and learned experience!
After reading the advice given to fix Mark's problem, I made the following checklist:
- Wire connections
- Change condenser
- Drain fuel at Zenith
- Pull bottom of carb & blow out
- Emty fuel tank & look for junk
- Open sediment bowl & check for flow there
- Do carb Heimlich maneuver
- Fuel flow at carb line like 14 yr. old not 63 yr. old (me!)
- Remove shut-off valve and check for junk
The results were amazing! Bug wings & bodies and sand in carb filter! Lots of small grit/sand in float valve! Fuel flow at carb end of line like a 63 yr. old after waiting too long...just a drizzle! Pulled bottom off sediment bowl...full of grit, rust & bug parts! Pulled fuel shut-off valve...completely plugged! Looked inside fuel tank...saw some rusty-looking small patches on bottom but no loose junk...apparently everything washed downstream!
I fired that mother up by noon today (already about 90 degrees here in Carthage, NC) and she ran good. So I took her out on the road for a cautious drive. After 5 miles she still purred like a kitten, I ripped along at up to 50 mph...no problems. So I got really confident and did some joy riding...big grin on my face! By the time I got back to the workshop, I had put 30 miles on her. No coughing, no "vapor lock", no engine quitting like before!!!
A big thanks again to Mark for asking the right questions and you other folks for being so good as to take the time and offer your best shots.
Blessings to one and all!

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I had the same problem with my car. I rebuilt the carb and did most of what has been suggested here. Eventually I traced it to an intermittent fault in a replacement ignition switch. Replaced the switch and no problems since . Good Luck Karl

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I had a problem like that with my 31 coupe. I finally was able to see (with a flashlite) something floating in my gas tank. I got a coat hanger and fished out what looked like a piece of burlap. It was about the size of a silver dollar. It just drifted around and would settle ever so often over the feed to the sediment bowl. I remember being so mad that day. She had sputtered out on me twice. When I got that piece out of the tank I stopped on it all the way home. I was flying !!! Probably hit 37 0r maybe even 40.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Running ethanol gas? Running a cork float? They dont play well at all. Replace with neoprene before you get a tank full of cork crumbs to clean out. I think the cork particles still have enough "float" to rise up out of the blocking position when vacuum is released when the engine dies. Small outboard motors with integral fuel tanks can drop tiny plastic shavings into the fuel line/jets. A real pain to blow them out.


Been there, done that.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

A lady in our club had the same problem with her dad's coupe. Turned out there was a leaf floating in the gas tank and would occasionaly float over the outlet/shutoff. I put in a stand up screen filter in the shutoff and it worked fine.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I'm running into a similar problem and didn't even think about the gas cap till I read it in this post. I had heard of this vent issue before but it didn't even click that I swapped caps around the time this issue started. Is partially opening the cap the only solution to this. Can it be vented another way or vents opened.

Bob

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

Well, if a partially open cap solved the problem, then the other solution is to get another cap. The bad repo caps have a center that moves when you tighten the cap, and the vent holes mis align and shut off the air much like a ball valve shuts off a liquid. They make a nifty hockey puck, small frizbee or moving target. I did see one that had been drilled all the way through with a 1/16th bit, but some gas will spurt out over the tank when its full.

Re: Driving & then COUGH COUGH & Died..10 min later start & Fine..& Died again.
 

I had the cap vent problem described by Pat. I drilled through the original vent hole in the center piece. I tapped the hole for a small screw and locktited in place. This locked the gasket to the cap center so it could not rotate to block vent.
I then drilled a new vent hole on the opposit side of the original hole. Be careful to only drill through the center and not the outer cap.

This has worked well for several years .

John