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

[msmaron]

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??

[Jason in TX]

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.

[msmaron]

Originally Posted by Elrod

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.

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?

[pat in Santa Cruz]

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.

[Vicky]

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

[msmaron]

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Originally Posted by pat in Santa Cruz

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.

YES as soon as it dies, there is spark the engine fires fine, it takes about 5-10 minutes and then lights up and goes!

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

Checked and CLEAN

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.

OK i see where you are going with it and i will try to see what i can find this week, Don't want any problems on the long drive to French Lick!
Thank you

[msmaron]

Originally Posted by Vicky

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

Brand new cap and checked that.

[marc hildebrant]

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

[msmaron]

Originally Posted by marc hildebrant

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

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

[pat in Santa Cruz]

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.

[Jerry Parr WI]

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.

[John Butts in CT]

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.

[steve s]

Originally Posted by pat in Santa Cruz

... 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.

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

[tamagrouchy]

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?

[Gerard]

Originally Posted by steve s

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

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

Gerard

[TerryH]

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!

[Mike V. Florida]

Originally Posted by msmaron

Brand new cap and checked that.

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

[Tacoma Bob]

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.

[gweilbaker]

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

[jaguar6165]

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