Engine cutting out

James Rogers

James Rogers

Well-known member
Got a stumper. I drove the Cabbie yesterday to the station to get some gas because it was about empty. I showered down in first and shifted to second. With the throttle floored in second the engine cut out like it was out of gas so, I just let up thinking it was about to run out of gas. Shifted into third and babied it to the pumps about a mile from the road to my house. After putting in about 2 gallons (10$) I thought, why not see if it was the low gas, so I kicked it in second and after a second or two it acted like it ran out of gas. Right about then when I thought it might be the gas cap not venting, I noticed the cap laying on the top of the tank. Top down so, I just stood up and reached over the windshield and replaced it. When I let up it goes on, no problem.

So I bring it home and disconnect the fuel line and let it run into a container to see if the tank was stopped up. No dice, I ran almost a quart and it was like a cow on a flat rock. I checked the sediment bowl and screen, clean as a pin. Dropped the carb bottom and it was clean also. I just don't know why it runs out of gas like that. I just had this carb rebuilt by Jim Adams about 6 months ago and it runs great except for this problem. The only thing I haven't checked is the float height but it runs great and does not stall at stops.
 
Gas or Electrical problem,I'd say electrical if it cuts out! Check wire in distr. or behind the panel! Vibration!
 
I had a similar problem with some old gas that had begun to turn into whatever "gas" turns into nowadays. Was the little amount of gas in your tank before adding the 2 gallons old? I replaced coil, condenser, carb, and ignition switch before I discovered the gas problem.
 
One clue you gave me in your post, you say you "floored it" in second gear. Sometimes when a sudden, high vacuum like that is brought forth a high amount of fuel from the carb jets, a very small piece of rust or foreign matter that was floating around in the carb passageway just under the secondary jet, can sometimes be forced up into the jet and now lodged there. You may not see it just by a minor dis- assembly.
 
Jim,

Is the problem essentially created when you floor the gas pedal? Is it ONLY in 2nd gear, or just worst in 2nd gear? Is there backfiring?

It's sounding to me like an electrical breakdown under load--when the pedal is floored at relatively low rpms, the engine is able to breathe deeply, raising the pressure in the combustion chambers, making it harder for the spark to jump the plug gap, making it more likely for high voltage spark to find an alternative path to ground. This should be worst in 3rd gear. If this is what's going on, there are many possible culprits providing either too-weak spark or too-easy alternative paths-to-ground.

Steve
 
Do you have a repro junction box and running an armored ignition?

If so, maybe the proud screw heads of the box are shorting to the firewall when being pulled by the cable from the massive torque of the mill?

Hey, you asked.
 
Zenith floats sometimes scrape slightly in an assembled carb, preventing full drop and complete opening of the valve. Without opening the carb (which would change the situation) remove the drain plug and see if you get the same full-flow stream you had when you disconnected the line.

I've also encountered some new float valves that tinkled worse than a bad prostate.
 
James,
With my stock cap, sometimes spark going to # 4 would jump through the cap to #3 plug connector strap & POW! I found it in the dark. Bill W.
 
BILL WILLIAMSON said:
James,
With my stock cap, sometimes spark going to # 4 would jump through the cap to #3 plug connector strap & POW! I found it in the dark. Bill W.
Click to expand...

Tom Wesenberg said:
I've seen two caps with the same 3-4 short.
Click to expand...

A very frustrated friend was ready to drive his A into the lake when, working in a dark garage, we saw one of the plug strips shorting to the distributor body, which, in turn, had scratches and carbon tracks completing the circuit to ground. Same problem for BOTH of the dist. bodies he had tried! We went thru the five bodies in my collection and found that the oldest, most beat up looking one worked the best--perhaps it was the only original Ford product.

Steve
 
Tom Wesenberg said:
I've seen two caps with the same 3-4 short.
Click to expand...
Tom,
For a temporary "fix" I made a high arched plug strap with a skinny strand of closeline wire & ran it for a month.:D Wonder if liquid tape would insulate a "leaking" cap???
Chief always carried wire in his A Models. When I opened my shop, he brought me 1/2 a roll of wire that he "rescued" from a hay baler he was rebuilding. Bill W.
 
steve s said:
Jim,

Is the problem essentially created when you floor the gas pedal? Is it ONLY in 2nd gear, or just worst in 2nd gear? Is there backfiring?

It's sounding to me like an electrical breakdown under load--when the pedal is floored at relatively low rpms, the engine is able to breathe deeply, raising the pressure in the combustion chambers, making it harder for the spark to jump the plug gap, making it more likely for high voltage spark to find an alternative path to ground. This should be worst in 3rd gear. If this is what's going on, there are many possible culprits providing either too-weak spark or too-easy alternative paths-to-ground.

Steve
Click to expand...
No backfire and I only noticed it in second. It is too cold and snowy to work on it right now so, I will leave it till later in the week.
 
gweilbaker said:
Do you have a repro junction box and running an armored ignition?

If so, maybe the proud screw heads of the box are shorting to the firewall when being pulled by the cable from the massive torque of the mill?

Hey, you asked.
Click to expand...
Original junction box with original screws and a armored cable with a repo switch. I build some good motors but that is a stretch.
 
MikeK said:
Zenith floats sometimes scrape slightly in an assembled carb, preventing full drop and complete opening of the valve. Without opening the carb (which would change the situation) remove the drain plug and see if you get the same full-flow stream you had when you disconnected the line.

I've also encountered some new float valves that tinkled worse than a bad prostate.
Click to expand...
I'll check that.
 
BILL WILLIAMSON said:
James,
With my stock cap, sometimes spark going to # 4 would jump through the cap to #3 plug connector strap & POW! I found it in the dark. Bill W.
Click to expand...
Bill, it doesn't misfire, it just quits like it runs out of gas. I let up and let the carb catch up and it runs great. Just don't hold it to the floor. I don't like to have to run with a light throttle.
 
James Rogers said:
Bill, it doesn't misfire, it just quits like it runs out of gas. I let up and let the carb catch up and it runs great. Just don't hold it to the floor. I don't like to have to run with a light throttle.
Click to expand...
Jimbo,
On Minerva, someone set the gas line too deep at the carb & the line touched the screen, worse still, it was touching the 1/4" wide solder joint down the side of the carb screen.:eek: Another time I had a little BLACK BEETLE stuck in the top of my float valve.:mad: Maybe it was a dreaded "CORN BEETLE!" that poops the goo that plugs our jets! (WHY ME??????) Bill W.
 
James I think it is fuel try opening the gav more counterclock wise to richin it up see if this helps, also try and pull the choke just when it falls on its face see if this helps. and like Mike said see if there blockage in the main jet
 
A couple of things to check:

1. Sometimes the plug on the bottom of carb for the main jet will have an indentation inside the plug where a small piece of Gasoline saturated cork or rust will be "floating" around on the bottom the plug.

Under high flow conditions (WOT) the gas flow will suck the cork up and block the main jet temporarily. Then at idle or lower speeds the cork drops back down and all is fine until the next WOT.

The same thing can happen inside the port for the cap jet/ secondary well also. Either one will limit gas flow.

2. Remember the flat thin piece of solder that forms when you flick some hot solder off of your solder iron onto the floor?

If the gas tank has been soldered in the past I have seen a flat thin piece of solder "floating" around in the bottom of the gas tank. Occasionally the solder piece will cover the outlet, stopping or limiting gas flow to the carb.

NOTE if the shutoff valve has a "finger" filter installed then this will not be a problem.
 
If I'm not mistaking when you floor a car and open up the carb the vacuum drops that's why when going high speeds our vacuum whipers slow down if you already have a slight vacuum leek in eaither the carb to Maifold or manifold to block when you floor it open you will loose vacuum and run to lean for and start feeling like your out of gas. Same sinaro happened to me about two yeas ago had a crack in my manifold ran ok (yet on the leen side) till I tryed to goose it. Then bla bla bla bog bog uhg thppp.
 
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